How Much Protein? By: Brad Pilon - Amazon...
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Transcript of How Much Protein? By: Brad Pilon - Amazon...
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How Much Protein?
By: Brad Pilon
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Copyright © 2013 by StrengthWorks International Publishing, Inc.
All rights Reserved
No portion of this book may be used, reproduced, or transmitted in any form or
by any means, electronic or mechanical, including fax, photocopy, recording, or
any information storage and retrieval system by anyone but the purchaser for
their own personal use. This manual may not be reproduced in any form
without the express written permission of Brad Pilon, except in the case of a
reviewer who wishes to quote brief passages for the sake of a review written for
inclusion in a magazine, newspaper, or journal, and all of these situations
require the written approval of Brad Pilon prior to publication.
The information in this book is for educational purposes only. The
information in this book is based on my own personal experiences and my own
interpretation of available research. It is not medical advice and I am not a
medical doctor.
The information within this book is meant for healthy adult individuals.
You should consult with your physician to make sure it is appropriate for your
individual circumstances. Keep in mind that nutritional needs vary from person
to person, depending on age, sex, health status and total diet.
If you have any health issues or concerns please consult with your
physician. Always consult your physician before beginning or making any
changes in your diet or exercise program, for diagnosis and treatment of illness
and injuries, and for advice regarding medications.
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Contents
Introduction 5
Protein Builds Muscle 13
Protein Basics 19
The Effect of Resistance Training on Muscle Mass 43
How Muscles Grow 48
The Muscle Building Effects of Protein 56
Building Muscle, Nitrogen Balance and Protein Synthesis 59
Testosterone and muscle growth 84
Non-Responders versus Ultra-Responders 92
Muscle growth and vegetarian diets 94
Muscle growth and low protein diets 97
Muscle growth and Very High protein diets 103
A Big Meta Analysis of the Research 111
Protein and meal timing 115
Post workout protein 119
The research that started all the confusion 122
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Post-Workout Protein – What’s Really Happening? 125
Ultra High Protein fails again 131
Protein and Muscle – An Alternative Hypothesis 134
Why Muscle Grows Easily When We Are Young 143
What Happens When We Don’t Workout 146
Protein and Muscle – Maybe it’s all a Race 151
Conclusions 158
My Best Recommendations 165
What I do not recommend 167
Final Thoughts 169
Eat Stop Eat, Protein Intake and Muscle Mass 172
Frequently Asked Questions 178
References 197
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Introduction
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Introduction
As you begin reading this book, you may be thinking to yourself “does
the world really need another book on protein?” The truth is this book is not
really about protein per se, but rather it is about building muscle. However, you
really can’t separate the two. Over the last 5 decades ‘protein’ has become
synonymous with ‘muscle’. When people think of bodybuilders, they think of
tuna, skinless chicken breasts, and protein shakes – lots of them.
So the purpose of this book is to examine the relationship between the protein
you eat and your ability to build muscle. In other words, I am trying to answer
the question – “Can nutrition – specifically the amount of protein you eat – help
you build muscle?”
Once this question has been properly examined we will then break it down into
two more direct questions – “Can the amount of protein you eat help build
MORE muscle?” and “Can the amount of protein you eat help you build muscle
FASTER?” After all this is really what we all want; MORE MUSCLE FASTER!
Protein is one of the most popular and controversial topics in all of nutrition. It
has become the ‘nutritional golden child’ of muscle building and fat loss. Some
people may try to avoid eating carbohydrates, and others may avoid fat, but
nobody avoids protein these days. In fact, the question has never really been
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“if you should eat protein”, but rather “how much protein should you eat” and
“when should you eat it”.
It may be hard to believe, but protein hasn’t always been considered the
nutrient that can do no wrong. Throughout recent history each of the major
macronutrients (protein, fat and carbohydrates) has taken its turn as the evil
stepchild in the trio.
In the early 1900’s diet gurus such as John Harvey Kellogg (the creator of the
modern cereal food giant Kellogg’s) and Horace Fletcher rallied against the
intake of dietary protein due to its “negative effects on digestion and health”.
[Polland M, 2008]
In the 1950’s Ancel Keys led the charge against fat, saturated fat and
cholesterol as he proclaimed they were the major cause of heart disease. His
campaigning was so successful that even to this day we all live in fear of dietary
fat even though there are hundreds of research papers that have since proven
that different kinds of fat have different properties in the body (including some
that are beneficial) and that dietary cholesterol may not have a cause-and-effect
relationship with the cholesterol our bodies.
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In the late 90’s and early 2000’s Dr. Robert Atkins lead the low carb revolution
claiming carbohydrates were the cause of all of our ills.
We are now living in the wake of the ‘low carb is good for you’ AND ‘fat is bad
for you’ eras. Both ideas are firmly rooted in the nutrition and fitness industries
as well as in the mind of the most people whom are interested in health and
fitness.
Protein has had enough time to get off the ‘bad guy’ list and is perfectly
positioned to take top spot on the podium of healthy nutrients. It has been
almost 100 years since Kellogg and Fletcher were trying to convince the
population that protein was the bad guy. By default protein is the only
macronutrient left that could possibly be good for us. So the stage is set once
again for protein to be the cure for all of our ills.
Fitness magazines constantly repeat the pro-protein message: “If you want to
build big muscles you have to eat your protein”, “If you want to lose fat and look
like a fitness model, then you have to eat your protein”. Browse the pages of
any popular fitness magazine and you will find the following two golden rules of
dietary protein:
1. Eat a minimum of 30 grams of protein every two to three hours.
2. Always drink your post-workout protein shake!
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When I first started working in the sports supplement industry I was a sales
person at a local supplement shop. I believed in these protein recommendations
and followed them with almost fanatical dedication. I drank my protein shakes
and ate my protein bars. In fact, it wasn’t unusual for me to drink 4 to 5 shakes
per day. I would constantly keep my protein intake up around 250 grams per
day. Why? Because I thought it was scientifically PROVEN that more protein
meant more muscle, and more muscle was what I wanted.
When a customer came into the store, it didn’t matter what they were shopping
for, I knew that I could convince them to buy protein. It wasn’t because I was
an amazing sales person, or that I was sinister or deceitful, rather it was
because I believed in protein so much that my enthusiasm became contagious.
I would get people so worked up about how great protein was for them that they
would end up buying two, sometimes three tubs of the stuff!
Nowadays, I realize that much of what I was led to believe as fact was really just
very clever (and powerful) marketing, combined with my inability to truly
understand the available research.
However, I’m not embarrassed by my mistakes. After all, if you’ve ever seen a
protein supplement advertisement you know how convincing they can be. The
protein supplement industry is massive, with projected sales of over 6 billion
dollars by 2011 [Packaged Facts, 2008].
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With this much money on the line, I’m sure you can imagine why so much time
and effort is spent on the marketing of protein supplements. But the sports
supplement industry isn’t the only one that stands to profit from the new
golden era of protein. Beef, poultry, pork, dairy and eggs are the major sources
of protein in the North American diet and you can bet these industries are
capitalizing big time on the new found love affair we have with protein.
These food industries dwarf the supplement industry so they have even more
money to spend on advertising to make sure you are reminded that protein is
the critical piece of your diet and fitness puzzle.
As an example of the food industry’s interest in promoting protein as healthy we
can look to the fact that the funding for the scientific meeting “Protein Summit
2007: Exploring the Impact of High-Quality Protein on Optimal Health” was
supplied by the following industries: Egg Nutrition Center, National Dairy
Council, National Pork Board, and The Beef Checkoff through the National
Cattlemen's Beef Association [Fulgoni VL, 2008].
The pro-protein message doesn’t just come from the industry side. According to
the mass media, there are many different reasons why we should eat more
protein, from improved overall health, to fat burning, to muscle building. On
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any given day you could find an article that says eating more protein will fix any
and all of your diet and fitness shortcomings.
The theory is simple: by eating more protein you can force your body to an
improved level of function, including larger muscles, less fat, and a host of
other health benefits. The question is whether or not the scientific research
actually supports these theories.
Protein has been given so many benefits by the media that it is hard to find a
health benefit that protein does NOT have. From preventing diabetes to building
muscle, protein seems to be able to do it all. These are some pretty big claims,
and it would be amazing if even half of these claims were true. The prospect of
curing many of the world’s health issues by simply increasing the amount of
protein we eat is definitely a very exciting concept, but again, we need to know
if it is indeed backed by scientific research.
Lately, the topic of how much protein has become even more confusing. While
the connection between protein and muscle is still as strong as ever, other
areas of research have shed some doubt on the “can-do-no-harm” view of
protein. Recent research in the area of cancer has suggested that a high protein
intake has a role in cancer development. Other research suggests high protein
diets may play a role in acne pathogenesis and even diabetes.
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This line of research is well beyond the scope of this book. However by the end
of this book I will not only give you my interpretation of the ‘how much protein
to build muscle research’ but I will also give you speculation as to why different
lines of research find different and opposing views as to the ‘healthfulness’ of a
higher protein diet. This being stated, it’s important to realize that this book is
about ‘how much protein to build muscle’ and not ‘how much protein for ideal
long-term health’.
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Protein builds muscle
In order to get to the bottom of this story and figure out just how much protein
we really need, it makes sense for us to start at the beginning.
Of all the claims about protein, the one that almost everyone simply accepts as
fact is that eating protein builds more muscle. Our assumption is that this is a
direct cause and effect relationship. You go out of your way to consciously eat
more protein each day, and this will cause your muscles to grow larger each
day. It is this one simple assumption that leads to so many of the additional
benefits of protein. Surprisingly, this assumption has never been fully proven.
Or more accurately, it has never been properly defined.
I can still remember the time when I first realized that protein might not be the
iron-clad muscle builder it was made out to be. It was during a very exclusive
dinner in Glasgow Scotland, where I had just put the finishing touches on a
new research contract examining the muscle building and ergogenic
(performance enhancing) effects of a new supplement.
It was a night of firsts for me. It was my first time to Scotland, my first time
trying scotch and blood pudding (and later in my trip, Haggis), and it was the
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first time I had ever had a world renowned scientist openly question my belief in
protein, in front of a table full of academics no less.
Charged As a True Believer
It was during the closing comments of the dinner, when the pointed comments
about protein came up. I had made a suggestion that adding protein to the new
formula may in fact increase the muscle building effects. The lead scientist
looked at me and said “Brad, if you BELIEVE in protein, then we will add it into
the formula”. As soon as I heard this statement I realized they understood and
knew something about protein and muscle building that I did not.
At this moment I realized I was missing some vital information about the
connection between protein and building muscle and that everyone else at the
table had this information. I felt as though my understanding was wholly
inadequate, as the concept of ‘belief’ has no place in a conversation about
known scientific facts. And if a scientist needed to caudle my feelings of belief
about consuming protein then they also recognized that I simply had not done
enough research to bring a sound scientific argument to this dinner table. It
was one simple gesture trying to appease me, but at that moment I felt like I
was in my first year of university all over again.
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In the world of science you do not ‘believe’ in anything, you either understand
the facts or you do not. Had the good doctor really been interested in my idea to
include more protein in the formulation he would have asked the simple
question that all scientists love to ask; “Why?”
In science, to believe in something means to have a certain amount of blind
optimism that you use to fill in the gaps where you’re missing the facts, which
is really a kind way of saying you’re already biased towards an outcome (not a
good allegation if you are in science). You will see this kind of biased optimism
from researchers who spend a great deal of time researching one particular
topic. They gain certain notoriety as an expert in the field, and then all of the
research seems to always have some sort of positive spin attached to it. This
has occurred recently with protein research and the research on fish oils. The
bottom line is that ‘belief’ isn’t good for research.
Afterwards, when I had arrived back in my hotel room, I started to think about
that statement “If you BELIEVE in protein”. Was I the only person at the table
who believed in protein? And what did they mean by ‘believe?’ – I thought it was
a scientifically proven fact? I thought they knew this to be true as well. An
uncomfortable feeling starting gnawing at me as I contemplated the very real
possibility that I was dead wrong about how much protein I or anyone else
really needed to eat to build muscle.
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Then my cognitive dissonance started to set in. “Whatever” I thought to myself
“I’m bigger than all those scientists, so what do they know?” Of course, I knew
that being ‘bigger’ did not justify my assumptions as to WHY I was bigger. I
started to feel silly for trying to give the credit of my hard earned muscle to my
protein intake instead of the combination of my years of hard work in the gym
and the genetics I was given from my parents.
After this trip I decided to get to the bottom of the story about dietary protein
and find the true scientific answer to what I thought would be a simple question
“how much protein do I need to build muscle”.
The purpose then of this book is to review the current body of scientific
research and find out if there is any truth to the alleged muscle building
benefits of protein. Specifically, it will examine the benefits of eating high
protein diets (In excess of the 90 grams per day that is the average intake in
North America [Fulgoni VL, 2008]), and it will also examine the muscle building
benefits of post-workout protein intake, and some of the more prominent
opinions on the ideal timing of protein intake.
I would like to take this time to point out that I do agree that it may be
completely possible that some of us need to eat a little more protein than we
typically do, (some people still consume less than the recommended amounts).
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I also recognize that protein malnutrition is a serious and documented health
condition (albeit mostly occurring in very young children), and that protein
supplementation may possibly improve the health of hospitalized adult patients
[Potter J, 1998].
I also absolutely do not want you do think that this is some sort of anti-protein
supplement manifesto. While I do not think that protein supplements are any
better than simple food, I also do not think that they are any worse. They’re just
another protein source in our diets. They are neither the Hero, nor the Villain
of this story.
The actual recommended amounts for daily protein intake vary from country to
country, but generally fall into the range of 40-60 grams of protein per day for a
healthy adult – Roughly the range of protein you might find in one large chicken
breast or 9 ounces of steak. Therefore, I will review the evidence that supports
the theory that we need “super-mega” amounts of protein that are well in excess
(triple or even quadruple amounts) of the recommended 40-60 grams per day in
order to pack on muscle. I will also review the research that supports the
necessity of post-workout protein meals (whether from foods or protein
supplements) for the purpose of muscle growth, and the research supporting
the need for specific timing of protein ingestion – whether or not multiple
feedings is superior to one large protein meal per day.
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As you are reading this book, please keep in mind that I am exploring the
specific question of “how much protein is needed to build muscle mass’. I am
not attempting to answer questions such as “how much protein to increase
longevity?” or “how much protein for optimal life-long health”. In order to keep
this book on topic (and less that 5,000 pages) we have to maintain this specific
focus.
Along the way to discovering how much protein we need to build muscle I will
show you the difference between an exact scientific end point like ‘increased
muscle mass’ or ‘increased muscle size’ and a surrogate end point like
‘increased protein synthesis’ and ‘mTOR activation’ and how these two very
different types of measurements end up being confused and lumped together as
the same thing for marketing purposes.
I also will share with you the exact amount of protein, or range of protein
intakes that an adult human needs to eat to allow for measureable increases in
skeletal muscle mass, and the rationale behind these ranges.
Finally I will explain where the fitness industry gets its information about the
effects of protein and how this information can be and usually is
misinterpreted.
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Protein Basics
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Protein
Carbohydrates
Fat
Protein Basics
In order to keep this book to a reasonable length I am going to quickly
review the basics of protein and protein digestion. Keep in mind that there are
massive textbooks on this topic. Protein metabolism is much more complicated
than this simplified explanation.
Along with fat and carbohydrates, protein is a "macronutrient," meaning that
the body needs relatively large amounts of it. Vitamins and minerals, which are
needed in only small quantities, are called "micronutrients." For example: think
of macronutrients like the wood, drywall and concrete needed to build your
house, and think of your micronutrients as the screws and nails. They are both
essential, one is just much bigger than the other.
Protein is typically found in the highest concentration in meat and animal
products such as milk and eggs. However protein is also found in most of the
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other foods you eat, including fruits and vegetables (albeit in much smaller
amounts).
Protein is made up of organic compounds called amino acids. Amino acids are
the building blocks of all the protein in your body and are found in the all of the
protein that you eat. What makes amino acids uniquely different from sugars or
fats is their Nitrogen content. Every amino acid contains at least one ‘amine’
group – basically a molecule of nitrogen and two hydrogen atoms. It could be
argued that the very reason we eat protein is for the amino acids that become
available once protein is digested. Think of amino acids like Lego blocks that fit
together to build a bigger block of protein.
When you eat protein it is broken down into smaller fragments of di, tri, and
oligopeptides (short chains of amino acids) as part of the digestion process.
These small fragments along with individual amino acids are then absorbed
through the gastro-intestinal tract and enter the blood stream. From there they
are transported throughout the body ultimately being re-incorporated into new
proteins (including muscle, organs, blood proteins etc) or used in various
metabolic pathways.
Amino Acid
Amino Acid
Amino Acid
Amino Acid
Amino Acid
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It is extremely rare to have longer chain or intact proteins enter the blood
stream from your gastrointestinal tract. When this does occur it may trigger an
immune response within the body causing ‘food allergies’. However, to be clear
this only seems to occur in rare instances where there is damage to the
intestinal track and larger proteins accidently slip through into circulation. So
whether you drink a whey protein shake or eat a steak dinner, all the protein
you’ve just consumed is broken down into amino acids. It is these amino acids
that enter your blood stream and not the fully intact ‘whey protein powder’ or
‘steak’.
It is important to note that the function of amino acids in the body involves
much more than just muscle tissue repair and growth. It also includes repair
and development of red blood cells, hair and fingernail growth, regulation of
hormone secretion, the creation of protein based hormones like insulin and
growth hormone, movement (muscle contraction), digestion, maintenance of the
body's water balance, protection against disease, transport of nutrients to and
from cells, the carrying of oxygen and regulation of blood clotting. At times the
protein you eat and even the proteins that are already in your body will also be
used for energy production.
Simply put, amino acids play a much bigger role than solely being building
blocks for muscle. In other words, if you were to eat 100 grams of amino acids
it is not as if those 100 grams would all be used for muscle building!
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As an example, the amino acid Glutamate acts as a brain neurotransmitter,
and the amino acid Glycine plays an important role in the development of red
blood cells.
There are twenty-two different amino acids that combine in various
arrangements to make up all the proteins in your body, including hormones,
enzymes, your internal organs and muscle tissue. Your body can produce the
majority of the amino acids by itself, however there are nine amino acids that
the body cannot manufacture, and thus it is essential to consume these amino
acids from your diet – hence why they are called the ‘Essential Amino Acids’.
The Nine Essential Amino Acids:
• Phenylalanine
• Isoleucine
• Leucine
• Lysine
• Threonine
• Methionine
• Tryptophan
• Valine
• Histidine
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In order for muscle and organ tissue to be built by the body, these nine amino
acids must be present in sufficient amounts, and therefore they must be
provided by your diet on a ‘somewhat’ regular basis.
It is the definition of ‘sufficient amounts’ and ‘somewhat regular basis’ that is
the center of the ‘protein builds muscle’ controversy. To date, we have never
had a scientific consensus on the amount of protein we should eat that
everyone would agree is sufficient, nor do we have consensus on how often and
when we should be eating protein.
In the late 1800’s researchers by the name of Carl Voit and Wilbur Atwater
recommended a dietary protein intake of 118 grams per day for adult humans
doing moderate muscular work.
In 1905 a scientist named Chittenden concluded “one-half of the 118 grams of
protein food called for daily by the ordinary standards is quite sufficient to meet
all the real physiologic needs of the body” [Chittenden RH, 1905]. Obviously this
was a very controversial recommendation – suggesting that the accepted 118
grams was DOUBLE what was actually required by the human body, and that
60 grams of protein daily was more than sufficient for most people.
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It should be pointed out that Carl Voit’s original recommendation of 118 grams
was questioned mainly because meeting this required protein intake would
hardly be feasible without substantial meat consumption, and at the time
vegetarianism was beginning to become a popular way of eating. So even back
in the early 1900’s it was a very convoluted mix of politics and scientific interest
that led to some of the controversy surrounding protein [Heyll U, 2007]
Even today, more than 100 years later this seemingly basic argument of ‘how
much protein’ still rages on, with differing recommendations coming from
different nutrition authorities, and due to very different reasoning.
Even government regulations within the same country do not agree on the topic
of protein. In fact, two such regulations, the DRI and RDA, are quite possibly
the two most confusing and misunderstood guidelines in all of nutrition policy.
DRI stands for Dietary Reference Intakes and it is meant to be the supporting
research and recommendations for governments and related health associations
for setting things like the Recommended Dietary Allowance (RDA). The
development of the DRI was a joint initiative by the United States and Canada
to expand and replace both the RNI (Recommended Nutrient Intakes) for
Canadians and the RDA (Recommended Dietary Allowances) for Americans.
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The process of establishing the DRI’s was managed by the Standing Committee
on the Scientific Evaluation of Dietary Reference Intakes of the Food and
Nutrition Board, the Institute of Medicine, and The National Academies in the
United States, in collaboration with Health Canada. The results appeared as a
series of reports from a panel of American and Canadian scientists starting in
1997 with the final report being released in 2004.
The DRI’s include recommendations for total daily energy (in calories),
carbohydrates, fiber, fat, fatty acids, cholesterol, protein and amino acids. This
DRI document is the supportive data for all the following recommendations;
Recommended Daily Allowance (RDA) in America, the tolerable upper intake
limit (UL), and adequate intake (AI).
The Recommended Daily Allowance (RDA) is the most widely recognized term
and has the greatest influence in daily nutrition practice. An American
committee known as the Food and Nutrition Board developed the RDA in 1941
and it has updated consistently every 5 – 10 years thereafter. The current RDA
uses the DRI as its foundation and is defined as follows:
The Recommended Daily Allowance is an estimate of the minimum daily
average dietary intake level that meets the nutrient requirements of nearly
all (97-98%) healthy individuals.
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So as high protein anti-RDA people like to point out, the RDA is ‘only a
minimum’, but as the low-protein pro-RDA people like to point out, ‘yes, but it’s
a minimum that meets the requirements of nearly 98% of healthy individuals’.
Which then leads us right back to trying to define the term ‘requirements’ and
no closer to understanding how much protein is optimal for muscle building,
and to what extent protein even affects the muscle building process. I’m pretty
sure the ‘minimum requirement’ for ‘most’ people doesn’t account for people
who want to build serious muscle.
The RDA for protein for adults (18 years or older) is 0.8 grams of protein per
kilogram of bodyweight per day (about 64 grams for a 175 pound person). The
RDA for protein was based on the results of all the available research that
estimate the minimum protein intake necessary to avoid a progressive loss of
lean body mass as reflected by a measurement called nitrogen balance.
You may be wondering ‘what the heck is nitrogen balance and what does it have
to do with my muscles?’ In order to determine if you need more or less protein,
scientists first have to determine a way of measuring the effect protein is having
on your body. In the case of the RDA, scientists chose nitrogen balance as their
measurement marker.
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The premise behind the nitrogen balance is relatively simple, amino acids
contain nitrogen, so measuring the balance of nitrogen in and out of the body
should give us some sort of idea as to the amino acid balance of the body.
While nitrogen balance is a scientifically valid measurement of the amount of
nitrogen moving in and out of your body, it does contain one small flaw - There
is no scientific evidence to date that nitrogen balance is an accurate measure of
any relevant physiological end point other than the amount of nitrogen moving
in and out of the body.
In other words, some scientists speculate that nitrogen balance might have the
ability to predict muscle gain or loss, but to date this theory has not been
proven. In fact, it’s the opposite – there is substantial scientific evidence to
show that nitrogen balance is NOT predictive of any long-term changes in
muscle mass, or really of anything other than the amount of nitrogen in your
body.
While this may sound like a very controversial statement, keep in mind that
even the Food and Nutrition Board acknowledge that using Nitrogen Balance to
set the RDA for protein was a major limitation due to its lack of accuracy and
applicability. Or, in there own words – “Because this method does not measure
any relevant physiological end point”[Wolfe RR, 2008].
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If that isn’t enough to raise your skeptical eyebrow, then you may be interested
to know that almost all of the research data used to come up with the RDA for
protein was calculated using college aged men. Few if any studies were done on
men of middle age or older, and almost no research exists on women.
So the current RDA for protein is simply a guess (based on the measurement of
nitrogen balance) at how much protein a healthy young man in college might
need. That’s it.
In reality we do have a general idea how much protein a person needs, but it is
also true that this idea is based on a lot of broad assumptions and estimates.
These assumptions and estimates are based on what we currently know about
human physiology and follow some very logical principles, but this does not
change the fact that they are still assumptions and estimates. Or, in non-
scientific terms, we have to remember that we’re just sort of guessing. And,
we’re guessing at a person’s ‘needs’ for health and not necessarily what is the
optimal amount of protein they need to eat to build muscle, if in fact protein
does help build muscle.
If you’re not confused enough with all of these acronyms and terms I’m going to
introduce you to one more – The AMDR.
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The AMDR stands for The Acceptable Macronutrient Distribution Range
(established by the Institute of Medicine in 2005). The AMDR is similar to the
other forms of recommendations accept that it is slightly more vague and allows
for a much larger range of protein intakes.
The major difference is that the RDA is a strict hard and fast number for
protein– 0.8g of protein for every kilogram (2.2 pounds) of bodyweight per day,
whereas the AMDR is a range with the RDA presumably as its lower end (but
not necessarily).
The AMDR for protein has been recommended at between 10%-35% of a
person’s daily caloric energy intake. This recommendation is dependent upon
how many calories you eat in a day, and how much lean body mass you have.
Total daily calorie requirements change based on day-to-day activity level, so
there is a huge amount of variation to this recommendation.
This still doesn’t help us answer the now not so simple question, “how much
protein?”
The AMDR is a rather large range (10 -35% of total daily calories) and it doesn’t
necessarily account for total activity level (sleeping all day vs. a marathon run),
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type of activity (a 2 hour run vs. a 2 hour power lifting workout), and the
specific goals of the activity (weight loss, muscle gain or fitness).
Lastly, if you look closely you’ll also notice that the AMDR is based on the
amount of calories you are eating, but not the amount of calories you SHOULD
be eating. Meaning if you should be eating 2,000 calories, but you are eating
5,000 calories for whatever reason, there is a range of 50 to 437 grams of
protein! Logically we can say that overeating by 3,000 calories does not
somehow create an essential need for almost 400 extra grams of protein per
day.
At this point you can see that the RDA is set as a minimum and might end up
being too low on high activity days. It therefore doesn’t give us any information
about what is optimum, and gives us absolutely no information about what is
needed to build muscle beyond the amount you naturally have with no weight
training.
On the other hand the AMDR gives us a very wide range that could have us
consuming two or three times as much protein from one day to the next.
It makes sense physiologically, economically and emotionally to avoid
chronically forcing ourselves to eat excessive protein if we know it isn’t
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necessary, especially considering protein food sources are typically the most
expensive and most forms (meat, fish, eggs and dairy) require energy for storage
(ie: fridges) and can spoil easily. However, it is also counter productive to eat so
little protein that we hinder our ability to build muscle mass, or possibly even
hurt our health in the long-term.
Therefore my goal for the rest of this book is to determine how much protein is
needed to build muscle and achieve your fitness goals without grossly under or
overestimating as the RDA and AMDR seem to do. In fact, the one good thing
we can take from the current protein recommendations is that the DRI does not
define a tolerable upper limit for protein. So at the very least it appears that
despite the large discrepancies in suggested protein intakes, there does seem to
be agreement that from a health standpoint there is no level of protein intake
that appears to be detrimental to the health of an average person, and least
from the point of view of these recommendations.
This brings us all the way back to the current scientific view of the amount of
protein that constitutes ‘sufficient amounts’. Some researchers argue that
‘sufficient amounts’ means 2 grams of protein per pound of bodyweight. That is
about 350 grams per day for a man who weighs 175 pounds. Others will argue
that a single dose of as little as 3.5 grams of essential amino acids may be
enough to allow your muscles to grow. This is roughly the amount of essential
amino acids found in one single glass of milk. That is a huge difference from
34
350 grams of protein. So which one is the right answer? Well it’s not that
simple.
A very interesting point about protein digestion is that your body’s ability to
digest protein can be up-regulated or down-regulated depending on the amount
of protein that you normally eat.
In other words, if you constantly eat high amounts of protein at every meal,
your body will be able to absorb high amounts of protein at every meal. If you
are not used to eating large amounts of protein and you suddenly start eating
double or triple the amount of protein you typically would eat, your body will
have a difficult time digesting the extra protein. This typically results in some
very bad Gastro Intestinal (aka: stomach and gut) upset and some rather
pungent flatulence.
Protein Consumption
Protein Absorption
35
If you were to suddenly double your protein intake, it would only take your
body a couple days to get used to all the extra protein. Some people make the
mistake of thinking this is proof that their body has started to build more
muscle once it has adapted to the new higher protein intake, but this is not
necessarily the case.
From examining the protein intake of many different cultures around the world
we are able to see that humans can survive on a wide range of protein intakes.
From levels as low as around 0.3 grams of protein per pound of body mass
(about 50 grams per day for a 180 pound man) all the way up to ten times this
amount in people who survive eating a diet that consists almost exclusively of
meat. Obviously, even though our protein intake can vary by a factor of ten
times, our muscle mass cannot.
There is no culture of people on earth who have ten times more muscle
than another culture.
Even the current champion bodybuilder, with all the amazing genetic potential
and anabolic steroid abuse, still does not have anywhere near ten times the
muscle of an extremely skinny Olympic long distance runner. So while people
can chronically eat massively different amounts of protein, this drastic
difference is not reflected in their muscle mass.
36
In fact, even finding two men of the same height where one has DOUBLE the
muscle mass of the other would be near impossible.
Consider that I weigh around 170 pounds and have about 10% body fat. That
means I have roughly 153 pounds of Lean Body Mass. Not every pound of lean
body mass is skeletal muscle. Organs, skin and bone also would count as Lean
Body Mass. In the average person Skeletal Muscle makes up about 50% of their
lean body mass, while in a well-muscled individual Skeletal Muscle Mass may
make up 55-60% of Lean Body Mass.
So assuming that I am fairly ‘well muscled’ this would mean that I have roughly
85 pounds of actual skeletal muscle mass. So for a man of the same height
(5’10”) to have double the muscle mass as me, they would need to have 170
pounds of Skeletal Muscle mass (just slightly less than the mass of my entire
body!).
If this man had the same amount of ‘other’ lean body mass as me (organs, skin,
blood, etc), then they would have 240 pounds of Lean Body Mass, and weight
roughly 265 pounds with 10% body fat. I have only ever seen this type of
musculature on someone using anabolic steroids…A LOT of anabolic steroids!
37
10 X More Protein 10 X More Muscle
Eating twice as much protein as I do will not turn a man into a 265lbs hulking
behemoth in our above example. In other words the relationship between
protein intake and total muscle mass is simply not linear – There must be some
sort of upper limit.
This is a very important point. One of the major ways we prove cause-and-effect
relationships in science is with something called a ‘dose response’. Meaning if
eating extra protein truly caused you to build extra muscle, then the more
protein you eat, the more muscle you should have. Since we now have evidence
that this does not occur, or at least it doesn’t continue with escalating doses of
protein, we need to examine the reasons why this relationship doesn’t exist.
Our bodies compensate easily to extreme variations in protein intake in a
number of different ways. As stated earlier your body can up-regulate and
down-regulate the amount of protein that is absorbed from the intestinal tract
after a meal. It can also up- and down-regulate the amount of amino acids that
get oxidized as fuel (burned for energy).
After you eat protein and it is broken down to amino acids in your gut the next stop
is the liver. Your liver acts as a regulator, controlling the flow of amino acids that
enter your blood stream. The liver not only serves as a type of stop-‐gate controlling
38
the flow of amino acids into your blood, but also stores some of them for later
release when food is not available – during times of fasting for example. In fact, after
a large whole food meal containing a high amount of protein, amino acids are being
released from your liver to your blood stream for a period of over 8 hours! Even
when amino acids are able to flood into your bloodstream (like when they are
injected during a research study), it still doesn’t mean your body is able to fully
utilize them all.
Research from Robinson et al, published in 1990 has shows that when you
suddenly start eating high protein your body starts to burn more amino acids
as fuel [Robinson et al, 1990]. This adaptation is logical if you consider it from a
supply and demand point of view. Your body can only get energy from the
protein, fat and carbohydrates (and sometimes alcohol) that you consume. If
you choose to eat more protein and less fat and carbohydrates, your body will
adjust to what you are doing and burn more of that protein for fuel.
The answer to the age-‐old question of ‘how much protein can you digest in one meal?’ is:
Your body can learn to digest very large amounts of protein, if given the proper amount of time to adapt
So our bodies can adapt and digest varying amounts of protein, as well as
absorbing varying amounts of amino acids. It can also handle large or small
intakes of protein by increasing or decreasing the amount of amino acids that it
burns for energy, if needed. This is an example of how our bodies are constantly
39
adapting to maintain a state of equilibrium or balance (aka: homeostasis). The
simplest way to view this is just as a healthy body has an incredible ability to
regulate levels of blood glucose, it also has the ability to regulate the levels of
blood amino acids. And, just as spikes occur with blood glucose after a big
meal, spikes can also occur with amino acids, and just like blood glucose these
spikes are typically dealt with quickly and efficiently.
The other major issue with following a chronic high protein diet that is well
above your needs is the possibility that by eating high protein you could
possibly up-regulate all of these ‘protein regulatory processes’. This up-
regulation could reach a point where you end up needing to maintain a high
protein diet just to meet your minimum protein needs. You could be creating a
chicken and egg scenario where chronically eating high protein creates a need
to continue to eat chronically high protein. This would most likely depend on a
number of factors, including not only how much protein you eat but how often
you eat it.
There are many other ‘facts’ about protein that simply do not make sense. For
instance, I have always found it interesting that bodybuilders and athletes have
accepted the goal of using ultra-high amounts of protein to try and force muscle
growth, rather than try to teach the body to be more efficient by attempting to
force muscle growth using normal or even slightly less than normal protein
intakes. After all, it has been suggested that this is one of the ways in which
40
anabolic steroids act to increase muscle size – allowing for a more efficient use
of available proteins and amino acids [Sheffield-Moore et al, 2000].
When I worked in the supplement industry, product development was all about
more protein. If a competitor had 40 grams of protein in their protein shake, we
HAD to have 42 grams. If they had 23 grams of protein in their protein bar, we
HAD to have 25 grams.
It is funny how we strive for creating a very inefficient process rather than
trying to optimize an already very efficient one. This is just one of the
nonsensical points about ultra-high protein diets.
Here is some more little known information about protein. If you were to eat 50
grams of protein on any given day, you would actually be digesting between 100
and 150 grams of protein! This is because your body also digests an additional
50 to 100 grams of endogenous protein every single day. Endogenous protein is
the protein that is secreted into your gastrointestinal tract by your body
(endogenous means that your body produced it without getting it from your
diet).
These proteins come from saliva, gastric juice, pancreatic enzymes and other
secretions as well as intestinal cells and proteins that have leaked into the
41
Daily Protein Supply
Food
Endogenous
Bacteria
intestine from the blood. We basically have a built-in protein recycling
operation, utilizing ‘scrap’ proteins that are no longer needed by the body to
build new proteins that are ‘in demand’.
Here is another piece of astonishing protein information. We may also absorb
amino acids from our colon that are created by our microflora (the bacteria in
our Gastro Intestinal system). In other words, there may be yet another,
previously unknown way that our bodies are supplied with the amino acids that
we require.
These facts make it clear that your body is in a constant state of cycling and
reusing its own proteins. Some of the amino acids in your right biceps may
have at one time been part of your heart, or part of an enzyme system in your
saliva.
The proteins and amino acids in your body are almost like interchangeable Lego
blocks. They can be built up and stored in one part of your body, then taken
apart and built up and reused in another part of your body.
42
Heart
Biceps
Blood Vessel
Enzymes
As long as you have enough Lego blocks available, your body will decide the
best place to use them. The same 20 different Lego block types (the amino
acids) can be used everywhere throughout your body to make millions of
different proteins, cells and structures.
To be clear: All throughout the day you are continually breaking down and
building up proteins in your body. It’s an ongoing cycle of anabolism and
catabolism – they don’t just happen one at a time!
Furthermore trying to only have anabolism by eliminating catabolism in the
name of muscle growth is kind of like only inhaling and never exhaling in the
name of health, it’s a futile attempt at breaking a cycle that already works
perfectly fine.
43
So as you can see, not only is your body incredibly efficient at adapting to
different levels of protein intake (both high and low), it is also very efficient at
making use of its own amino acids, by recycling them in and out of different
body systems and tissues when it has to.
Now that we know the basics of protein digestion and absorption we will answer
the more pointed questions of “how much protein (or more specifically, how
much EXTRA protein) is needed to fuel the muscle building process?” and “Do I
need to eat protein immediately after my workouts in order to gain muscle?”
However, before we answer these questions, we must first examine the effects
that resistance training (weight lifting) has on muscle mass.
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The Effect of Resistance Training on Muscle Mass
45
The Effect of Resistance Training on Muscle Mass
I think just about everyone will agree that working out with weights (or
any other form of resistance) will result in increased muscle mass given that the
effort used is high enough and the rest and recovery is adequate.
It was more than 30 years ago that a group of experts scientifically proved that
the amount you use your muscles is the main factor in influencing how big they
are (other than genetics and height). In other words, how much and how often
you stress your muscles dictates how big your muscles will become [Goldeberg
AL, 1975].
For example, a muscle that is consistently trained with heavy weights gets
bigger and stronger, conversely a muscle that is in a cast and cannot move gets
smaller and weaker (just think of any time you or anyone you know has had a
cast on an arm or leg for any length of time – Once the cast came off I’m sure
you noticed that limb had become significantly smaller and weaker while it was
immobilized in the cast). In fact, the muscle loss that occurs with lack of use
(such as prolonged bed rest or space flight) is not prevented by nutritional
measures. In other words muscles must be used and worked if they are to grow
[Brooks 2012].
46
Muscle growth is also specific to the type of resistance it is forced to endure.
Each muscle fiber in our body is extremely small. Even in bodybuilders the
fibers are still really, really small – And with good reason. In order to remain
functional Muscle fibers require nutrients supplied by the blood, so fibers must
be small enough to allow diffusion of these nutrients from the capillaries to
supply their energy and waste-disposal needs. Depending on the type of
exercise, the fibers have different needs. A muscle that is chronically involved
in long endurance-style training has a requirement to stay within a certain size,
since its needs for nutrients and waste-disposal is high (muscle metabolism
makes a lot of bi-products that need to be removed by the blood).
Weight training on the other hand, does not have as high a nutrient
requirement as endurance training, nor does it create as much waste. It does
however need to produce a lot more force. Therefore weight training increases
the size of a muscle fiber, since it is not limited by its nutrient needs, but does
need to get bigger in order to create the required force.
If you read through all the research on resistance training and muscle growth,
you would find the average amount of muscle mass that is typically gained by a
healthy adult man or woman through resistance training is about 2 to 5
pounds over the course of 8-16 weeks [Cureton KJ, 1988; Abe T, 2000; Abe T
2003; Hartman 2006; Bhasin S, 1996; Treuth MS, 1994; Kraemer WJ, 2003;
Hartman JW, 2006; Hartman JW, 2007].
47
Therefore, from this research we see that in healthy, fully grown adult men and
women a really good resistance training program combined with an adequate
diet (ie: not following a very low calorie diet for an extended period of time) can
cause gains in muscle mass between 2-5 pounds in 2 to 4 months, regardless of
any extra nutrition or supplements.
As a rule of thumb, a really good resistance-‐training program should be able to cause a fully grown adult to gain
2-‐5 pounds of muscle mass in 2 to 4 months, regardless of any extra nutrition or supplements
Based on this finding, 2-5 pounds is what we can call the baseline increase in
lean mass we can expect from a good weight-training program. This baseline
depends on a number of factors including but not limited to age, sex, height,
training background, workout intensity and workout design.
Supplement ads and magazine headlines may tell you that you can gain 15-20
pounds of muscle in a single month, however actual scientific research suggests
that this is simply not possible in fully-grown healthy adult humans without
the aid of anabolic steroids, or without some previous growth stunting
occurring (people recovering from malnutrition or extreme muscle wasting will
see large increases in muscle mass, but only as they return back to what would
be considered a normal amount for their height and age).
48
Obviously our estimate of an increase in muscle mass between 2-5 pounds in 2
to 4 months is conservative, and meant to represent a very large population of
people. For some people (such as young men between the ages of 18 and 25) the
gains in muscle size may be more than double our estimates (close to 10
pounds), but rarely will they ever approach an increase of 15-20 pounds of true
muscle weight, unless their beginning amount of muscle mass was somehow
artificially low – perhaps due to an underlying illness.
Now that we know the average increase in muscle that is caused by resistance
training, we need to ask how does this occur? Or, more precisely what makes a
muscle become larger?
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How Muscles Grow
50
How Muscles Grow
We know that weight training on its own can add about 2-5 pounds in 2-
4 months, we need to next ask “how exactly do muscles grow?”
Your muscles are made up of a collection of microscopic fibers simply called
‘muscle fibers’. Muscle fibers are long narrow fibers that can run the complete
length of your muscle. In fact, a single fiber in your thigh can be almost a foot
long in length.
51
Inside each of these fibers is the sacroplasm, which is largely comprised of
‘myofibrils’ – the stuff that makes your muscles contract. A typical muscle fiber
can contain anywhere from 100’s to 1,000’s of myofibrils.
Now if you look closely at these fibers you will see little purple dots on them,
these are the nuclei of the fibers, sometimes referred to as myonuclei.
These nuclei are like the governing body of the muscle fiber. They control
everything. However, they can only control a small section of any given fiber.
This area is called their domain (kind of like a castle and its kingdom). The
‘domain’ is the sarcoplasm – the stuff that is packed with the contractile and
metabolic machinery of the fiber, so the nucleus oversees all of the metabolic
processes on your muscle fiber [Luff & Atwood 1971].
52
Because muscle fibers are so long they need multiple nuclei, which is very
important in our quest to understand muscle growth. Research has shown us
that no matter how big a muscle fiber becomes, the ratio of nucleus-to-domain
remains relatively equal. Research has also found that under normal
circumstances, adult skeletal muscle is a very stable tissue with very little
turnover of nuclei [Charge SBP, 2004]. This means that as a muscle fiber
grows, somehow it needs to find more nuclei, and this is where satellite cells
come into play.
Satellite cells are like ‘dormant muscle seeds’ that sit on the outside of the
muscle fiber (hence the name satellite cells). They are present in all skeletal
muscles and are associated with all muscle fiber types - albeit with unequal
distribution (some muscles have more some have less) [Charge SBP, 2004].
When muscle fibers are damaged through resistance training, satellite cells are
activated, and move into the muscle where they provide new nuclei for muscle
fiber growth (now that the muscle has a new nucleus it can add more ‘domain’
around the nucleus) [Robertson 1990; Toth KG 2011].
You can think of satellite cells as the body’s reserve of muscle cell nuclei. In
fact, because muscle cells are ‘post-mitotic’ meaning they cannot create new
nuclei by themselves, they have to rely on satellite cells as the exclusive source
of new nuclei for the maintenance and growth.
In fact, satellite cells are considered ESSENTIAL for the physiological
adaptations that drive muscle growth. Amino acids may be an essential
53
building block for creating new muscle, but it is the satellite cell that truly
makes all the magic happen.
Scientists have tested the importance of satellite cells by using low dose
radiation in animal studies. In this study one of the animals legs are exposed to
radiation while protecting the other leg. The radiation effectively ‘kills’ the
satellite cells in the exposed leg leaving the satellite cells useless, while the
other leg still has its full compliment of satellite cells.
When this happens the muscles exposed to radiation can still adapt to exercise
by becoming more efficient, but with the exception of a small amount of
beginner growth, they simply cannot increase their size. [Rosenblatt 1992;
Adams GR 2002]. In other words, because they couldn’t add more nuclei, they
could not increase their size in response to resistance training. In other words,
all the amino acids in the world don’t help without the ‘brain’ that puts it all
together.
With the exception of the small amount of growth that is possible with the
amount of nuclei already existing in a muscle fiber, muscle growth is absolutely
dependent on satellite cells being activated and moving inside the muscle.
And while this seems like some very dry science, it does become very important
when we start looking at the role that protein plays in muscle growth.
Let’s take a moment to review what we know so far:
54
1. We know that resistance training stimulates satellite cell activation,
which is what drives muscle growth.
2. We know that 4 to 5 pounds of mass gain as a result of 3 months of
training is a conservative estimate of the muscle growth potential in
healthy adults.
What we do not know is the role that dietary protein plays in this process.
However, before we tackle this problem we do need to address some of the
common claims that are made regarding muscle building.
It is easy to argue that the suggestion of gaining 20 pounds in one month is an
unrealistic expectation set by the supplement and fitness industry. I can
remember when a claim of 50 pounds of muscle growth in less than two
months was made in a supplement advertisement, a noted researcher sent me
an email which read:
“I am sorry, but even in an untrained person on 3,000 mg of testosterone a week and
taking growth hormone... they still would not even come close to being able to build that
much muscle.”
So while we do know that muscles can grow, we also know that there are logical
limitations to this growth, and that exaggerated marketing claims of 20 pounds
of muscle growth in as little as one month are not going to be supported by the
available scientific research. So the point of this book is not to try and dispel
these types of grandiose claims, but rather to try and uncover the amount of
dietary protein necessary to support the anabolic effects of resistance training.
55
Lastly, we have the problem of rate – or the speed at which one can build more
muscle. If during an 8 week study, one group of men gains 4 pounds of muscle,
while a second group gains 6, we do not know if the second group saw a higher
absolute gain, or if they simply gained at a faster rate, and if given more time,
say an additional 5-6 weeks, if both groups would gain an equal amount of
muscle at some predetermined muscle gaining ‘limit’. For sake of argument lets
say that group two stopped growing at week 10, plateauing at 7 pounds of total
muscle gain, while the first group plateaued at 7 pounds at week 13. It’s
difficult, if not impossible to tell if studies are showing higher absolute gains in
muscle, or simply faster gains in muscle, with the same inevitable ending point.
The current published scientific research to date has outlined some of the more
important aspects of muscle growth including the role of testosterone and
growth hormone, and the extreme importance of the inflammatory response to
muscle growth. And, all of these components are important. However, none of
them fully explain the role of dietary protein in the muscle growth process and
whether it can affect the absolute amount of muscle a person can gain, or the
rate at which those gains can occur.
Therefore, based on the scientific findings we have discussed to this point, and
excluding the odd genetic freak that we all know, but cannot full explain (may
be genetics, may be drugs, or a combination) we can now ask the question, “If
working out without the addition of ultra-high daily protein intakes can cause a
56
person to gain 2-5 pounds of muscle, what happens if they increase their daily
protein intake above normal amounts?”
Or in more simplified terms, we can call 5 pounds our ‘normal and expected
level of growth’ and look for evidence that eating high amounts of protein can
cause muscle growth beyond this number.
57
The Muscle Building Effects of Protein
58
The Muscle Building Benefits of Protein
High protein diet advocates would like you to believe there are literally
thousands of research studies proving the effectiveness of high protein diets for
building muscle. The truth is that there are relatively few studies done on high
protein diets and muscle building. In fact, there is much more research on low-
protein diets then there is on high-protein diets! [Garlick PJ, 1999]
I’ll be the first to admit that there is a strong theoretical basis for expecting a
beneficial effect from an increased protein intake. I believed this was true for
many years and I’ve even helped formulate several different protein powder
supplements in the hopes of helping people put on more muscle.
I can also tell you that nobody wants protein to work for muscle building more
than I do. If all it takes to build extra pounds of muscle is drinking an extra
whey protein shake or two I am all for it.
We do know that there is a strong relationship between protein intake and
muscle growth – It’s not as if you can simply do away with all of the protein in
your diet for long periods of time and not expect to lose a significant amount of
muscle mass, regardless of whether or not you are weight training. What we
don’t know is whether or not this strong relationship is permissive (you need a
certain amount to allow for the muscle building effects to occur) or if it’s causal
59
(the amount of protein you eat dictates how much muscle you will grow – dose
response).
Increasing the availability of amino acids does increase whole body nitrogen
retention and muscle protein synthesis, at least for a little while. And if amino
acids can increase nitrogen retention and muscle protein synthesis then we
need to define these phenomena and explore how it they are measured.
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Building Muscle, Nitrogen Balance and Protein Synthesis
61
Building Muscle, Nitrogen Balance & Protein Synthesis, is there a difference?
To understand where the story of protein and muscle began, we need to
move away from all the research that actually measured changes in muscle
mass and take a look at all of the tracer studies that show a post workout
increase in something called “protein synthesis”.
You’re probably asking yourself “what is a tracer and why would anybody use it
to study changes in muscle mass? Why not just measure actual changes in
muscle mass?”
Well skeletal muscle turns over very slowly – at a rate of 1.5-2% per day. This
means that even at its absolute fastest muscle growth is an incredibly slow
process. And, this rate is not constant, as it fluctuates throughout the day
[Garlick PJ, 1973]. In fact, it is so slow that it is simply impossible to detect any
changes in muscle mass during a short period like hours or days no matter how
advanced and sensitive the measuring devices are that the scientists are using.
62
This fact posed a significant problem as scientists became interested in how,
when and why muscles grew. Specifically, they wanted to know what caused
muscle growth after only one workout.
Since scientists do not yet have the tools to measure what they actually want to
measure (very small changes in actual muscle mass) they have to look for
something else that might be an indication or “marker” for what they want to
measure.
In research we call this a surrogate endpoint. We use something we can
measure and assume it tells us something about what we cannot measure. In
this case, we measure markers of protein synthesis assuming they are an
indicator of muscle growth. In other words, muscle mass growth is the true end
point we want to measure but cannot.
If we assume that muscles need amino acids to grow, and we can measure the
amount of amino acids going into and out of muscles, we could guess that if
more amino acids are going into and less coming out of a muscle, it must result
in growth.
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Instead of measuring actual changes in muscle mass scientists use the
incorporation of amino acids into a muscle as the surrogate end point that we
can measure.
Definition:
Surrogate endpoints are often physiological or biochemical markers
that can be quickly and easily measured, and that are thought
to be predictive of a true clinical end point.
The most basic explanation of how we measure protein synthesis is as follows:
Scientists use radioactively labeled amino acids to track their movement inside
the human body [Rennie et al. 1982; Wolfe, 1982].
Basically, these amino acids are identical to normal amino acids, with the
exception of having a slightly different mass – so using some fancy methods of
analyzing mass (using mass spectrometric techniques) we can actually ‘see’ and
follow exactly where they go in the body. It’s sort of like putting a tracking
beacon on a car in a busy city and watching it drive through the busy city
streets from a helicopter overhead.
A couple of hours after infusing the body with these labeled amino acids, a
small piece of muscle is removed (this is called a ‘biopsy’) and the amount of
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labeled amino acids that entered the muscle tissue is measured. The amount of
labeled amino acids incorporated in the muscle tissue is used as a ‘marker’ of
the protein synthesis going on in this tissue.
Obviously, this is an overly simplified explanation of how we measure protein
synthesis, but there are some points we need to consider when exploring the
protein synthesis research.
Firstly, since these methods require constant tracer infusions, they are only
suitable for measuring ‘acute’ time periods - a couple hours at most. They also
have to be conducted in a controlled laboratory setting. This is why you rarely
see muscle protein synthesis research that lasts longer than 6 hours.
Secondly, the measurements of the amino acids that are being incorporated
into protein is difficult and has given rise to much debate - So not everyone
agrees on what is actually being measured, or how it should be measured.
Finally, there are actually very different ways of measuring protein synthesis.
There is the ‘constant infusion method’ and there is also the ‘flooding method’.
The most obvious difference between the two is that in the first method in order
to measure synthesis we have to do a biopsy (remove a small amount of
muscle), in the second we calculate synthesis from the amount of labeled amino
acids that disappears from the blood as it passes through the tissue – no biopsy
is needed.
65
The issue with there being different types of measurements is that it makes it
difficult to compare studies. The values from the flooding technique are
typically higher than those measured by constant infusion. In fact, this
discrepancy has led to much debate about the validity of these two methods
overall.
Plus, even if two research studies were identical in every other facet of their
design, but one used continues flooding and the other used constant infusion it
would be very difficult to compare their results.
It has even been suggested that the large amount of labeled amino acid given
during flooding might itself stimulate muscle protein synthesis, thus giving rise
to an artificially high measured rate by this method.
As negative as this may sound, and despite their shortcomings, these
techniques have made a big impact on our understanding of how muscles grow.
Research using these techniques has shown that when amino acids are
provided at a constant rate, muscle protein synthesis increases after about an
hour, stays increased for about 90 minutes, then returns back to normal levels,
even when amino acids are still present [Bohe J 2001].
So while eating protein can increase rates of protein synthesis in your muscles,
these effects are short lived. This process also seems to have a defined upper
66
limit, as providing more amino acids doesn’t make this response any larger, or
last any longer [Atherton et al. 2010].
However, these findings on protein synthesis cannot really be discussed without
also addressing the role that eating protein has on protein breakdown. While
protein synthesis can only be stimulated for a couple of hours, providing the
body with amino acids doesn’t just stimulate protein synthesis, it also serves to
decrease the rate that amino acids LEAVE the muscle (called protein
breakdown).
Muscle growth involves the balance between amino acids entering and amino
acids leaving the muscle. To say it in a simpler way, muscle growth is the
combination of both synthesis AND breakdown. We cannot exclude the fact that
while larger protein meals may do no better at stimulating protein synthesis
than smaller protein meals, they may provide a slow release of amino acids into
the blood stream that may decrease protein breakdown for several hours post
meal.
However, this would be a good place to mention that we would never want
protein breakdown to stop all together, as it is an extremely important way that
our body regulates the health of our body.
If you remember, workouts damage your muscle fibers, and when that damage
is repaired is when our muscles ‘grow’. Well, that damage repair involves the
removal of broken muscle fibers. This is protein breakdown.
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So we WANT protein breakdown, but we only want the optimal amount. Any
extra breakdown would theoretically slow our ability to gain muscle size. If
muscle protein breakdown is too low, we risk build up of damaged tissue inside
of our muscles.
To summarize, research on protein synthesis has allowed us to discover that
the effects of eating protein involve a quick increase in muscle protein
synthesis, that returns to normal after about 2 hours, and then is refractory
(meaning cannot be stimulated again) for 3-4 hours after this, even if amino
acids continue to be present in the blood stream. Protein breakdown research
reveals a much slower, less pronounced affect of eating protein that decreases
the amino acid release from muscles, albeit for a much longer time period
[Humayon MA, 2007].
Despite these advancements there still remains one small problem: The net flux
of amino acids in or out of a muscle does not, and has not been shown to equal
true long-term muscle growth; it is still a scientific assumption, based on
extrapolating information over a very small period of time, and assuming it
remains constant over a much longer period of time.
It seems reasonable to assume that having a net influx of amino acids suggests
the muscle is in a state that would allow it to grow. After a maximal load of
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amino acids your fractional synthetic rate can increase by as much as 90% over
normal, and after a workout it can increase by as much as 250%. However this
increase only lasts for 1-3 hours, even when amino acid levels in the blood
remain elevated [Bohe J et al, 2003; Atherton PJ, et al. 2010].
These are the studies that are typically referenced by the people who advocate
high protein diets and post-workout protein, while stating things like “high
protein after your workout is PROVEN to increase protein synthesis”
Unfortunately, we do not know whether acute measurements of protein
synthesis are PROVEN to indicate long-term increases in muscle mass in all
people and in all cases. And as we have just discussed, we don’t even know if
tracer studies are actually showing muscle growth at all, or just a lot of amino
acid movement in and out of muscles. Remember your body uses amino acids
like Lego blocks and reuses them constantly all over your body, a temporarily
elevated flux doesn’t necessarily mean more muscle growth. It is completely
logical to assume that these markers are indicative of muscle growth, it just
hasn’t really been proven yet.
The important thing to remember with these research trials is that they are
acute. In other words, they examine what happens during a very short period of
time.
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If you were a subject in one of these studies, your day would have gone
something like this...
You would be asked not to workout for 3 days, after which you would show up
at a research lab around 10 PM, and you would go to sleep (no eating). The
researchers would wake you up around 6 AM and start poking and probing you
(again no eating). After a bunch of weighing and measurements, you would
start working out around 9 AM...you still haven't eaten yet.
This would be one of the toughest workouts of your life. Most likely you would
do 10 sets of 8 reps on the leg press machine, followed by 8 sets of 8 reps on
the leg extension machine. All of your reps would be done at close to 80% of
your one rep max. Like I said, a brutal workout.
By the time you finished you would be exhausted and it would be about 10 am.
It would then finally be time to eat.
After your workout you would be given a drink that contains 3 to 6 grams of
essential amino acids (the same amount of amino acids found in a glass of
milk).
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After that, the researchers would take measurements for the next 4 hours and
measure your rate of 'protein synthesis'.
This is pretty much the standard protocol for these types of studies, and in
these studies researchers almost always find an increase in protein synthesis
over the two to four hours that they measure after your workout. (And
remember when I say ‘protein synthesis’ we are actually talking about the
movement of amino acids in and out of muscles that is ASSUMED, but not
proven, to mean protein synthesis)
So what does this prove? It proves that if you haven't worked out in 3 days, and
you have eaten since 10 PM the night before, and you do a brutal workout at 9
AM the next morning, and drink the equivalent of a glass of milk, you will
increase your assumed protein synthesis for four hours.
In other words, more amino acids would be going into your muscle then would
be coming out of your muscle during the 4 hour testing period! That’s it.
So if this is, in fact, a true measure of muscle growth then it definitely disagrees
with the idea of needing at least 30 grams of protein every 2-3 hours. As we
have just seen the people in these studies haven’t eaten in approximately 15
hours when they are supposedly ‘building muscle’.
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Furthermore, the only reason I say protein synthesis increases for 4 hours is
because the researchers stopped taking measurements after 4 hours. Who
knows how long you would have stayed in a muscle building state. Some
researchers have estimated that a single workout can put you into 'muscle
building mode' for as long as 48 hours after your workout [Phillips SM, 1997].
Even more interesting is that researchers have found similar results when they
made people drink the amino acids before their workout, and even when they
made them wait and drink the amino acids a couple hours after their workout
[Tipton KD, 2001; Rasmussen BB, 2000].
While this research does point to a connection between amino acid intake after
either fasting or a single workout and amino acid incorporation into a muscle, it
does not show muscle growth. It does show that amino acids from protein can
stimulate protein synthesis [Bennet WM, 1989] and that they are able to do so
in a ‘dose dependent manner’ – meaning the more amino acids you consume,
the higher this measurement becomes [Bohe J, 2003], but again, it doesn’t
prove actual long-term, measureable muscle growth.
However we also know that massive changes in the amount of protein you eat
does NOT create proportionately massive changes in muscle mass, leading to
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further speculation that the measure of changes in protein synthesis to suggest
changes in muscle mass may be flawed, or that things are happening later in
time to ‘balance out’ the amount of muscle growth that occurs as a response to
feeding. Or, that there is a dose response, but only to a certain ‘point’ at which
everything levels off (basically a muscle building ‘ceiling’).
Even when amino acids are infused into a muscle at very high doses, muscle
protein synthesis increases and peaks at about 120 minutes, but then it
returns to baseline levels, even when amino acid concentrations remain
elevated and anabolic signaling molecules like mTOR remain activated [Atherton
PJ, 2010]. This suggests that muscles have a limit to how quickly they can build
new proteins, and for how long as well.
In fact, because these are acute trials that only measure a couple of hour’s
worth of markers, they actually can NOT show muscle growth. They can only
show the results of a marker that if interpreted incorrectly could make you
assume that the muscle was growing or will be growing.
Even then, the doses of protein used are very small (typically the amount of
amino acids found in a glass of milk) and the timing doesn’t seem to be overly
important (before workouts, after workouts or 2 hours after a workout all
significantly increased these markers). But again, it is essential to remember
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that none of these research studies actually found a measurable increase in
muscle mass. And isn’t that what we’re interested in anyway?
This leads me to a very interesting study published in 1992 that provided some
startling evidence that illustrated the problems with these acute measurements.
Since proteins contain about 16% nitrogen (just a rough average), scientists can
make estimates of the amount of nitrogen consumed in food and the amount of
nitrogen we lose on a daily basis and use this estimate to calculate our
“nitrogen balance”.
The scientific assumption is as follows: if our nitrogen balance is positive we are
using protein to synthesize new tissues, such as enzymes, cell structures, and
structural proteins like organs and muscle. If our balance is negative we are
losing protein in the form of energy or nitrogen containing waste products like
urea.
Using these basic principles, researchers measured both the nitrogen balance
(one of those markers I was telling you about) and gains in muscle mass in
young men who were eating either a high-protein or low-protein diet while
following a resistance training workout program. These subjects were
performing an intensive hour and a half of resistance training 6 days a week for
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4 weeks. This research is very important because it measured both acute
markers measurements (nitrogen balance) AND actual long-term gains in
muscle mass.
After 4 weeks the people on the high protein diet (1.2 grams per pound of
bodyweight) had a significantly higher nitrogen balance than the people on the
lower protein diet (0.61 grams of protein per pound of bodyweight). Based on
our scientific interpretation of nitrogen balance measurements, these people
should have gained muscle mass.
The low-protein diet resulted in a nitrogen balance that was actually
NEGATIVE, suggesting losses in muscle mass.
Incredibly, despite these nitrogen balance findings neither the high or low
protein diet made a significant difference on the amount of muscle mass
increase.
Even the researchers called these findings surprising, stating that if the
nitrogen balance measurements were an accurate indicator of increases in
muscle mass, then over the one month period the high protein diet should have
caused a 17 pound increase in muscle mass! [Tarnopolsky MA, 1992].
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Obviously the massive effects noted in these acute measurements of nitrogen
balance simply do not add up long term, as a 17 pound increase in muscle
mass would have been an absolutely tremendous increase. Similar findings
have been found in other studies where the results of the Nitrogen balance
measurements indicate increases in Lean Body mass that simply did not occur
in the actual study [Lemon 1992; Tarnopolsky MA, 1988].
Research using nitrogen balance does show us that increases in protein intake
will cause a measureable but transient retention of nitrogen in the body. But
unfortunately that is all they seem to show us.
What we do not know for sure is whether this nitrogen retention is a true
marker of muscle growth (or it is just another surrogate endpoint).
Many scientists agree that the use of nitrogen balance as a surrogate endpoint
to show increases in skeletal muscle mass is flawed [Jackson AA, 1999]. And
truthfully, we’ve known about these flaws since as early as 1976 [Hegsted
1976].
There are many other explanations for positive nitrogen balance, which include
use by other nitrogen sources in the body that turn over much more quickly
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than muscle, or even an unrecognized error in the scientific methods of
studying nitrogen balance.
In fact, the weight of the current evidence suggests that the positive Nitrogen
balances associated with a high protein diet do not correspond to increased
lean tissue, and particularly not increases in skeletal muscle [Garlick PJ, 1999].
The bottom line is that to date we have little proof that any of these surrogate
endpoints such as nitrogen balance or tracer studies actually indicate long-
term muscle growth.
This makes sense for a number of reasons. Firstly these trials are done almost
exclusively in acute situations. Only the metabolic effects of the few hours
following one single workout are measured and then these results are used to
guess at what happens after a series of workouts.
Secondly, most researchers are very quick to point out that their findings
indicate transient increases in protein synthesis. Transient is another way of
saying that something is only happening for a very short period of time, and is
most likely going to change or return to existing levels very quickly.
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Even newer, more sophisticated surrogate endpoints like the phosphorylation of
anabolic signaling proteins are still causing scientists to be even more
confused. We now know that many amino acids (specifically leucine) can act
like signaling molecules within the body. In other words, amino acids such as
leucine almost act like a hormone inside our bodies, turning on various
anabolic signaling pathways within the body [Hutson SM, 2001].
So protein (or more accurately the amino acids that make up the protein you
eat) serves many purposes in the muscle building process. The most obvious
being to act as the actual ‘bricks and mortar’ that create the architecture of a
muscle, and they also serve a purpose of being a nutrient signal that turns on
some of the muscle building processes [Jefferson LS, 2001].
And while the link between leucine and the mTOR protein had scientists excited
that we had ‘unlocked’ the mechanisms of muscle growth, It has recently been
shown that an increase in the phosphorylation of the anabolic signaling
proteins ‘PKB’ and ‘p70S6K’ can occur without any changes in protein synthesis
[Greenhaff PL, 2008].
Supporting this finding is the research we discussed earlier with Satellite cells
and radiation. In the legs that were exposed to radiation, weight training
resulted in very limited muscle growth. Despite this fact the mTOR protein
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signaling pathway was still activated. So the signal was still there, but without
the satellite cells, it didn’t/couldn’t cause muscle growth [Kadi 2004].
Now we have evidence that ‘key’ anabolic pathways can be activated without
causing any changes in protein synthesis, and that protein synthesis can
change without causing any measurable changes in actual muscle mass!
While this is bad news for people who market things like mTOR activators, it does not mean that studying these
pathways is a waste of time – It simply means the relationship is more complicated than we thought
With all of the available research it seems evident that the findings in acute
trials simply do not always translate long term.
There are large differences between the acute metabolic effects of dietary protein
that happen as an acute response to single high protein meal versus the
subsequent adaptations that occur to the longer term intake of a high protein
diet.
In fact, most adaptations happen within the first 3 days after an increase in
protein intake.
So while it is true that in a wide variety of studies high protein intake has been
shown to result in continued positive nitrogen balance and even an increased
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protein synthesis. It is not known whether this apparent retention of protein is
real, how long it persists, and what form the Nitrogen is taking within the body.
These responses make sense, since without them we could simply eat a lot of
protein, and eat it very often and our muscles would become bigger. If only it
were this easy.
We know that adults humans in different cultures survive on a wide range of
protein intakes, spanning from a marginal level of 0.3 grams per pound of
bodyweight all the way up to as high as 3 grams per pound of bodyweight per
day. [Garlick PJ, 1999]. Despite these different intakes, there does not seem to
be any significant differences in muscle mass across these populations.
So simply eating more protein is not the key to having more muscle – since
there seem to be limitations to how the body reacts to protein feeding, with both
a limit to how much protein synthesis can occur, and to how long protein
synthesis can occur before the machinery of the muscles need a break.
This is where an extremely important point needs to be made. This data is in
normal human beings; Meaning – not in people who are resistance training.
And, there seems to be some sort of relationship between resistance exercise
and protein intake. Resistance exercise can change the way your muscles
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respond to dietary protein, but in the longer term it may actually decrease your
dietary protein requirements [Todd 1984; Butterfield 1984]
Resistance training can also stimulate muscle protein synthesis. After a period
of weight training, there will be a short latent period where no changes occur,
then muscle protein synthesis will rise sharply between 45 and 150 min and
may be sustained for up to 4 h [Kumar et al. 2009b] in the fasted state, and in
the presence of increased amino acid availability, the increase in protein
synthesis can last up to and beyond 24 h [Cuthbertson et al. 2006].
However, even with exercise, ‘protein synthesis’ does not always mean
measurable muscle growth. Endurance-type exercise such as running or
cycling is also associated with increased synthesis of mixed muscle proteins
acutely (∼50–60%) [Harber et al. 2010]. However, these acute responses are not
associated with significant changes in muscle mass, i.e. growth of larger
muscles.
This has to do with exactly where the protein synthesis is occurring, and is why
resistance training (lifting weights) and resistance training properly (lifting the
right amount of weights) is able to increase the size of your muscles.
As it turns out from the protein synthesis research, not only can resistance
training increase muscle protein synthesis, but it also changes your body so
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that you simply ‘react’ better to protein feedings. Basically, if your are
consistently weight training, using the proper amount of weight and proper
amount of volume, you will react better to protein feeding then someone who is
not weight training. Your ‘anabolic response’ to amino acids will last slightly
longer, just enough to give you a benefit that tips the scale towards anabolism,
or muscle growth.
Despite these facts, the science behind protein and muscle growth is not as cut
and dried as it may seem. There is still a serious debate as to how much muscle
we can add, and how protein influences this number.
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The difficulty arises when we consider the fact that muscle grows very, very
slowly. Your muscle mass will ‘turn over’ at a rate of 2 to 8 times per year
[Smith et al, 2010]. Compare this to your internal organs with a turnover rate
that can be as quick as once every 24-48 hours and you will see that muscle
‘grows’ very slowly, which makes muscle growth difficult to measure during
short or medium length studies (anywhere from 4 weeks to 6 months in
duration).
Nevertheless, the research that actually measures increases in muscle mass (as
opposed to measuring markers of protein synthesis or nitrogen retention) does
not support the theory that there is a dose response relationship between
protein intake and muscle mass (the more you eat the bigger your muscles get),
or that this dose response continues with ultra or mega doses of protein.
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My life experiences tend to support these findings. When I was working out
diligently in my early twenties I did a two month experiment where I drank a
protein shake every three hours, including waking up in the middle of the night
to make a shake, yet at the end of this experiment I did not put on any
measureable amount of muscle (Remember, I had access to an exercise
physiology lab, so my measurements were made using a BodPod and were
accurate and consistent).
I have also experimented with starting every day with a breakfast that consisted
of 100 grams of protein (A protein shake, egg white omelet and two cups of
whole milk). During this experiment, I didn’t change my workout regimen at all;
therefore I could conclude that the extra protein did not result in any
measurable increases in muscle mass. However, this is purely an anecdotal
experience; to truly determine if there is a muscle building effect of protein I
had to ignore my own personal experiences and attempt to use scientific
research to answer the question “Can eating extra protein build muscle?”
To accomplish this I reviewed research that studied changes in muscle mass
using advanced techniques like Dual energy X-ray absorptiometry (DXA),
Magnetic resonance imaging (MRI), air displacement (BodPod) or water
displacement (underwater weighing). These are some of the most advanced
measurement techniques science has to offer that actually measures true
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changes in muscle mass. If any research was going to show a benefit, this
would be it.
I also reviewed the research that used markers of muscle growth such as
‘protein synthesis’, ‘mTOR activation’ and ‘nitrogen balance’ as these were the
studies most commonly used to support the muscle building effects of protein.
My goal was to find research that used healthy individuals (men and women)
between the ages of 18-55 and examine how much change they could see in
their muscle mass, and how long it took for that change to occur.
Using these search criteria I was able to find several examples of significant
muscle growth with and without the intake of extra protein. I will review some
of the better research studies over the next few pages.
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Testosterone and Muscle Growth Studies
One of the most interesting studies showing the effect of resistance exercise
without any extra protein was published back in 1996. 43 men who were
experienced weight lifters took part in research that involved exercise and
weekly injections of anabolic steroids (testosterone enanthate) for 10 weeks
[Bhasin S, 1996].
The men in the study were divided into 4 groups; working out or not working
out, and receiving weekly steroid injections or not receiving them.
* Group 1: NO EXERCISE + NO STERIODS
* Group 2: EXERCISE + NO STERIODS
* Group 3: NO EXERCISE + WEEKLY STEROID INJECTION
* Group 4: EXERCISE + WEEKLY STEROID INJECTION.
It is probably no surprise that after 10 weeks of lifting weights 3 times per
week, the group that was receiving the steroid injections and working out
gained a very impressive amount of muscle (over 13 pounds!).
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It is also not surprising that Group 2, (the group who were working out but
didn’t get any steroids) also increased their muscle mass, packing on almost 4.5
pounds of muscle in only ten weeks – In line with our ‘based’ level of 2-5
pounds.
What was surprising is that the men who were injected with steroids and then
sat around doing nothing for 10 weeks amazingly saw an increase in lean mass
that exceeded what the guys working out but not without steroids gained.
Imagine gaining over 6 pounds of lean mass just by sitting around on your
couch all day not lifting a finger!
Obviously, the group who did not receive any steroids and didn't workout did
not see any change in their lean mass.
So what does a study on steroids have to do with protein? Well, all four groups
were on the same diet. They were all consuming about 0.7 grams of protein per
pound of body weight (roughly 120 grams of protein per day) and about 16
Calories per pound of body weight.
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This research clearly shows that approximately 120 grams of protein per day
was enough for a group of men taking steroids and lifting weights to gain 13.5
pounds of lean mass! Even in their steroid-heightened anabolic state, 120
grams was enough to supply all of the necessary building blocks for a 13.5-
pound gain in lean mass.
Interestingly, it was also the same amount of protein that Group 2 the exercise-
only group ate to gain 4.5 pounds of lean mass. So even though we know that
these men consumed enough protein to provide for a 13.5-pound increase in
lean mass, they only saw a third of this increase. The difference was obviously
due to the anabolic effects of the steroids and NOT due to the protein intake.
15lbs
10lbs
5lbs
0lbs
Muscle Gain
All four groups consumed approx 120 grams of protein per day.
4 2 3
Groups
1
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Since the 120 grams was also the same amount of protein that the control
group ate (who not surprisingly saw no change). It seems apparent the protein
ITSELF did not have any growth promoting effect above the effects of the
testosterone itself.
This study shows us that you can gain an impressive amount of muscle without
increasing your protein intake to super high levels (albeit it, through the use of
anabolic steroids). It also shows that protein alone does not cause the body to
increase muscle mass. In fact, resistance training and the combination of
resistance training and steroids can have dramatically different effects on lean
body mass without any change in protein intake at all.
You could argue that if they did eat double the protein that somehow they
might have all gained double the muscle, however the idea that doubling their
protein intake would have doubled their gains is not supported by any previous
evidence. You could also argue that if they had doubled their steroid dose while
keeping their protein intake exactly the same they would have seen even higher
increases in lean body mass (this suggestion is supported by research showing
a dose response to anabolic steroids). Especially when you consider the results
of the next study.
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In 2005, a similar research paper was published examining the connection
between testosterone and muscle growth. 52 men in their sixties received
varying doses of the anabolic steroid testosterone enanthate in doses ranging
from 25 mg, 50 mg, 125 mg, 300 mg and 600 mg weekly for 20 weeks [Bashin
S, 2005].
During this time frame the men were instructed to avoid any resistance
training or heavy endurance exercise.
The men ate about 90 to 110 grams of protein per day and about 2,400 to
2,700 Calories per day.
At the end of the 20 weeks, without working out or eating massive amounts of
protein, these men put on a very impressive amount of fat-free mass. The group
getting the highest dose of testosterone gained 16 pounds of fat free mass in 20
weeks without any exercise. Even the group getting 125 mg of testosterone per
day gained 9.5 pounds of fat free mass in 5 months.
Therefore, in these studies on steroids, as long as testosterone levels are
elevated, men can gain muscle while eating typical amounts of protein.
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In both of these studies, slightly above average protein intake in the 70-120
gram range (depending on bodyweight) was enough to allow for very large
increases in lean mass.
These studies confirm what many others have already found – There is a direct
and causal link between testosterone levels (in both men and women) and
muscle mass. And, that manipulating testosterone levels can cause massive
decreases and increases in skeletal muscle mass without any change in protein
intake what so ever.
What is very interesting about this connection between testosterone and muscle
mass is that this testosterone induced muscle growth is associated with a dose
dependent increase in the number of myonuclei, and the of number satellite
cells available to the muscle for future growth [Sinha-Hikim 2003]. In other
words it seems that intake of anabolic steroids in combination with resistance
training causes an increased activation of satellite cells, above and beyond what
would normally be found with resistance training alone [Kadi F, 1999]. These
findings effectively line up the role of testosterone in muscle growth with our
understanding of how muscle growth occurs (satellite cell activation and the
addition of more nuclei to the muscle fiber).
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At this point you might be thinking, “True enough, but still - these guys were on
steroids!” The take home message is that in each case protein was not the
limiting factor to muscle growth, it was testosterone. These studies clearly show
these men were consuming more than enough protein to gain impressive
amounts of muscle if enough testosterone was given. The next step is to
determine how much muscle can be added without steroids or added protein.
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Muscle growth and protein – Non-Responders versus Ultra-Responders
We can examine the roll that dietary protein plays in muscle growth by using a
technique called ‘cluster analysis’ to try and determine why some people gained
more muscle than others when using the exact same resistance training
program [Thalacker-Mercer et al, 2009].
In this study, 60 untrained healthy men and women took part in a 16 week
workout program training with weights 3 days per week. At the beginning and
again at the end of the study the researchers measured the cross sectional area
of the vastus lateralis myofibers (the size of the muscle fibers in one of the thigh
muscles). Based on this measurement the subjects were divided into one of the
following groups:
• Non-responders (Change in muscle size was about -16 +- 99 um2, lean
mass increased by a little over half a pound)
• Moderate-responders(Change in muscle size was about 1,111 +- 46
um2, lean mass increased by about 2 pounds)
• Ultra-responders (Change in muscle size was about 2,475 +- 140 um2,
lean mass increased by 3.75 pounds)
After the people in the study were placed into the appropriate group the
researchers analyzed their diet records to see if they could find any correlation
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between what the people ate, and how much their muscle size increased in
response to exercise.
In the results of the study, despite massive differences in the increases in
muscle size the researchers found no recorded difference between any of the
groups in the amount of protein the subjects were eating on a daily basis
(between 70 and 80 grams per day), the amount of Essential Amino Acids
(Between 27 and 31 grams per day) or Branched Chain Amino Acids (Between
12 and 14 grams per day).
Obviously there are limitations to using diet records in research. We’ve known
for a long time that people are notoriously bad at remembering what they ate,
and how much they ate. However, the vast majority of diet records are
uniformly inaccurate, meaning that it’s highly unlikely that one group was any
worse than the other at reporting what they ate (in reality, we’re all really bad at
it!) So while there may be some debate to the amount of protein these people
ate, it’s unlikely that there was a large discrepancy between the groups.
This study showed that slightly higher than average protein intakes (again in
the 70-120 gram range) is adequate, and perhaps even optimal for muscle
growth in some individuals, but it also shows that such an intake does not
guarantee muscle growth in others, even when in combination with a 16 week
long weight training program.
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While it would be easy to suggest that more protein may have helped the ‘non
responders’ gain more muscle, a follow up study published in 2008 suggests
that satellite cells were the culprit for deciding how much muscle a person did,
or did not gain.
In line with our previous findings on how muscles grow, this research found
that the people who started the study with the most satellite cells, ended up
adding the highest increase in muscle mass [Petrella JK, 2008]. In other words
the ‘ultra-responders’ started the study with the most satellite cells, and thus
by the end of the study had gained the most muscle mass.
This cluster analysis research clearly illustrates that the determining factor in
how much muscle you can gain is related to the amount of satellite cells you
have available for muscle growth. It doesn’t discount the role of protein in
muscle growth, but simply illustrates that a wide degree of muscle growth is
possible at relatively equal protein intakes, and without the use of post-workout
supplementation.
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Muscle Growth and Weight Training In Vegetarians
We can look at the research that explored the effect of resistance training on
vegetarians as another way to assess the need for protein. Not only do
vegetarians eat somewhat below average intakes of protein, they also obviously
do not eat any animal meat, which in the sports nutrition world are largely
considered to be the most “anabolic” of all protein sources.
In a study published in the scientific journal ‘Medicine Science, Sports and
Exercise’, two groups of people were asked to follow weight-training programs
for 8 weeks [Burke DG, 2003].
Both groups followed the exact same high volume, heavy load resistance
training workout program for the 8 full weeks.
The only difference between the groups was that one consisted of people who
have all been vegetarians for at least the last 3 years of their lives. They were
either lacto-ovo (milk and eggs only) or even stricter forms of vegetarians. The
other group consisted of people who ate the traditional North American diet that
included all forms of meat.
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The vegetarian group ate almost 450 less calories per day than the non-
vegetarian subjects, while the non-veggie group ate around 1.75 times more
protein than the veggie subjects (79 grams per day versus 138.5 grams per
day). Neither group took any form of post-workout supplement other than
creatine monohydrate (A supplement often used to increase muscle size).
The two groups were further subdivided into two more groups, his time with
people either taking creatine or not taking any form of supplement.
So the study design ended up looking like this:
* Group 1: VEGETARIAN + NO CREATINE
* Group 2: VEGETARIAN + CREATINE
* Group 3: NON-VEGETARIAN + NO CREATINE
* Group 4: NON-VEGETARIAN + CREATINE
By the end of this study all four groups had gained similar amounts of lean
mass (between roughly 2-5 pounds, the exact amount we would expect from a
resistance training program of this length). The only group that was
significantly different was the vegetarian plus creatine group, who gained
slightly more muscle weight than the non-vegetarian plus creatine group.
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This research illustrates that muscle growth is possible without eating ultra-
high amounts of protein, and also suggests that once minimum protein (and
calorie) requirements are met, adding more protein and more calories does not
seem to increase the total amount of lean mass that is gained from a resistance
training program.
From this research we can see that 79 grams of protein per day was enough to
allow for muscle growth, and 138.5 grams of protein per day did not seem to
promote any ADDITIONAL muscle growth. This evidence is in keeping with the
previous studies, in which 70-120 grams of protein was enough to allow for an
impressive amount of muscle growth in most (but not all) people studied.
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Muscle Growth and Low Protein Diets
Now that we have seen a couple different examples of muscle growth with
normal protein intakes, we can also look at the research examining what
happens when people follow a resistance training program while eating a low
protein diet.
It is generally believed that low protein diets instantly cause large losses of
muscle mass. From a scientific point of view this belief may be short-sighted.
When a person is transferred from a high protein diet to a low protein diet there
is a delay before the body comes into balance, and during this time there is a
net loss of nitrogen from the body, which people believe indicates a loss of
muscle mass. However, this loss is only transient and represents a change in
proteins that are easily lost or gained when intake is altered, but doesn’t
necessarily represent a permanent change in muscle mass [Munro et al, 1964].
In other words the temporary negative or positive nitrogen balances which occur
when the intake of dietary protein is drastically altered reflect a lag in metabolic
adaptation [Waterlow et al, 1968]. Research has found that it takes about 7 days to
adapt to a low protein diet, with some nitrogen loss, however it is lost preferentially
from the liver and gut (not your muscles) [Adds et al, 1936].
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So studying short periods of low protein diets may give us a false idea of what
happens over the long term. However, there are groups of people we can study for
long term results of a lower than normal protein diet.
When diets are extremely low in protein (under 0.25 grams of protein per pound
of bodyweight) for extended periods of time, skeletal muscle will have to be
catabolized (broken down) to obtain essential amino acids. This will result in
decreased lean body mass, especially in the elderly [Hansen RD, 2000;
Castaneda C, 2000; Campbell WW, 2001; Morse MH, 2001]. You cannot go
without any protein at all, but we still need to determine, how low is too low?
People with chronic renal insufficiency must eat a very low protein diet as this
disease impairs their ability to process protein. For these people eating even a
normal amount of protein would be dangerous. So any research showing that
these people could gain muscle would prove that muscle growth is possible with
a very low protein intake. It can also show us if eating small amounts of protein
can actually CAUSE losses in muscle mass.
A group of scientists decided to study the effect of resistance training on people
with chronic renal insufficiency [Castaneda C, 2001]. The scientists postulated
that these people would be at risk for losing muscle mass because of their
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inability to eat enough protein. These scientists were working under the
assumption that weight training would be the best way for these people to
maintain their lean body mass and build their muscles.
The people in this study were all over 50 years of age and were eating a very low
protein diet. On average these subjects were eating slightly under 0.3 grams of
protein per pound of body weight. To put that into perspective, a 180-pound
man would be eating about 50 grams of protein per day, for 12 weeks.
According to the current fitness industry dogma, this amount of protein is
probably 3 times lower than the amount of protein needed for building muscle.
At the end of the study, the subjects working out 3 times per week maintained
their body weight, while the group that was not lifting weights lost about 7
pounds. This type of weight loss is very typical with this disease (to be clear a
low protein diet alone will not cause this kind of rapid weight loss).
The group lifting weights also saw increases in muscle strength and muscle
size. Meanwhile the group that was not weight training lost some muscle and a
little bit of strength.
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This study is a great example of people actually maintaining and possibly even
gaining muscle size as a direct result of resistance training while on a low
protein diet.
I realize the study was done on people who were over 50, and had a medical
condition, and who were eating a diet much lower in protein than I would ever
recommend. Despite these facts, this research does show that weight training
alone can build muscle size even in these people who for medical reasons can
barely reach the minimum daily requirement of protein.
It is possible to suggest that these people would have seen better gains in
muscle mass had they been able to eat more protein, but this would have been
extremely difficult in these people given their medical condition.
So we do not know if we would have seen better results if more protein was
consumed, but at least we know that we can still see some results even when
protein is lower than average for an extended period of time.
From this collection of research it seems that the range of 70-120 grams of
protein per day was enough to allow for substantial muscle growth. Going
slightly below this range did not cause muscle loss, but it also did not result in
large increases in muscle mass.
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While we did see evidence that going above this range did not improve the
subjects ability to gain muscle mass, it is logical to suggest that the doses of
protein in the research I have reviewed so far were all too low to see any result.
In fact, it could be that we need ‘super massive’ doses of protein to cause
muscle growth.
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Muscle Growth and Very High Protein Diets
One of highest doses of protein I could find was in a study published by Burke
et al in 2001. In this study Forty-two men between the ages of 18 and 31 were
divided into 3 groups. The first group supplemented their diet wit an additional
0.54 grams of protein per pound of body weight.
To put this into perspective, for a 180-pound man that’s approximately 100
EXTRA grams of protein per day from protein powder. This is the equivalent of
taking about 5 extra scoops of protein powder every day in addition to your
normal protein intake!
The second group took the same amount of extra protein plus an additional
0.045 grams of creatine per pound body weight (about 10 grams of creatine per
day for a 180 pound man). The third group received 0.54 grams of maltodextrin
(a simple carbohydrate) per pound of body weight as their supplement (the
placebo group).
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The whey protein group gained about 5 pounds in six weeks, while the placebo
group somehow managed to gain an insignificant 2 pounds. Impressively, the
group taking creatine gained 8.8 pounds of lean tissue mass! [Burke DG, 2001].
These findings agree with the findings of the other studies that have shown that
resistance training in conjunction with protein intakes above 120 grams of
protein per day do not increase muscle mass above the 2-5 pounds we would
expect to see from resistance training, unless it is accompanied by the use of
creatine monohydrate [Hoffman JR, 2006].
However, if you look closely something interesting did happen with this study.
The subjects had an average increase of about 5 pounds of lean body mass and
they did it in only 6 weeks. This suggests another possibility; protein may not
Muscle Gain
1 lbs
5 lbs
10 lbs High Protein
Placebo
High Protein + Creatine
What you need to know: The high protein groups drank their shakes in 4 equal servings throughout the
day (this was not a post-‐workout trial). This research was funded by MuscleTech Research and
Development Inc..
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make you grow more muscle, but it may help you grow the same amount of
muscle faster than you would without the extra protein.
We’ve seen that massive amounts of protein (well above the 70-120 gram per
day range) do not cause muscle building above the 2-5 pounds we can expect
from a resistance training workout, but it may possibly allow you to build that
2-5 pounds a little faster. The next question to answer is what happens when
we eat a huge amount of calories with our protein?
High Protein + High Calorie Diet and Muscle Growth
In a research study published in 2002 by Rozenek et al, 73 healthy men were
assigned to an 8-week workout program and divided into three diet groups.
• Group 1 consumed an extra 2010 Calories per day that included an extra
106 grams of protein.
• Group 2 consumed an extra 2010 Calories but only 24 extra grams of
protein.
• Group 3 did the same 8 week long workout program, but didn’t have to
drink the extra 2010 calories.
I don’t know if you’ve ever tried this, but drinking an extra 2010 calories per
day is actually very difficult to do. Not only is this an incredibly large, incredibly
thick shake, but it also makes you feel sickly full for hours.
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I once designed a Mass Gaining shake that contained roughly 2000 calories per
serving, and I can distinctly remember trying to avoid doing any of the flavor
testing for this product, because after about 2 servings, I was too full to eat for
the rest of the day! To put this into perspective, it was like downing 2 extra
large fast food style milkshakes every day and then trying to eat your normal
food.
Luckily the people in this specific trial managed to drink all of their shakes AND
eat their normal meals. After 8 weeks all 3 groups made significant gains in fat-
free mass. The high protein group gained a little over 6 pounds, the
Carbohydrate group that only received an extra 24 g of protein gained almost
7.5 pounds of lean mass and the group who did not receive any supplements
still gained over 3 pounds of fat free mass.
Let’s say that again.
Between the two groups who took extra protein, the group who took LESS extra
protein gained MORE muscle.
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To put it into perspective, the group getting no supplements gained a little over
3 pounds of fat-free mass and dropped about 2 pounds of fat while eating
roughly 2,400 Calories every day. The other two groups gained between 6 and 7
pounds of fat-free mass, didn’t lose any fat, and were eating roughly 4,500
Calories every day.
The difference in the amount of protein the men were eating clearly had little to
do with the weight gain as the lower protein group gained more mass than the
high protein group. This suggests that the people in the group eating an extra
24 grams of protein had possibly already maximized the muscle building
Muscle Gain
0lbs
5lbs
10lbs 2010 extra calories + 24 grams extra protein
Placebo
2010 extra calories + 106 grams extra protein
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potential of protein, and that the men in taking the extra 100 grams of protein
were simply eating in excess of what they needed.
An interesting finding in this trial was that even though the 2-5 pounds of the
muscle that was gained was within the range we would expect, the time course
(8 weeks), that it took to gain this muscle was on the lower end of the amount
of time we would expect for these types of gains.
What you need to know: The high calorie groups drank their shakes in the morning and at night (this was not a
post-‐workout trial). The group with the best gains (green bar) still consumed roughly 120 grams of protein per
day.
Hopefully by now you are starting to see a trend. No matter how the story is
spun, if you are working out, taking a little protein, a lot of protein, protein with
carbs, protein with over 2000 extra total calories per day, or no protein at all
you should expect to gain about 2-7 pounds of lean mass after roughly 2-4
months of working out.
Considering our ‘baseline’ muscle gain from working out alone was 2-5 pounds
of muscle, these results hardly seem to support the need for post-workout
protein, or high protein diets.
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There seems to be evidence to suggest that a higher range of protein intake (in
the 70-120 grams per day range) is beneficial, but anything above this amount
does not seem to increase the muscle building effects of a weight-training
program to any degree that is measurable in research studies of 2-6 months in
duration.
The range of 70-120 grams of protein per day was also enough to allow women
involved in a weight loss experiment to actually increase the cross sectional
area of their muscle fibers while on a weight reducing diet – These women
actually gained muscle size while losing over 30 pounds of bodyweight.
[Donnelly JE, 1993].
It was also the amount that allowed women to gain lean body mass while
following a resistance-training program, even though they were also on a
severely calorically restricted diet. [Hunter GR, 2008].
In fact, if we look through actual scientific research what we find is that to
scientists the words ‘high protein’ generally refer to a range of 1.2 to 1.5 grams
of protein per kilogram of body weight – an amount higher than the current
government recommendations but certainly much lower that the 1-2 grams per
POUND of bodyweight that we see in most of the fitness magazines.
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In scientific studies ‘High Protein’ = 0.55 to 0.7 grams of protein per pound of body weight.
In fitness and supplement advertising ‘High Protein’ = 2 to 3 grams of protein per pound of body weight.
When we consider this range to be ‘high’ then it is true that there is an
abundance of research which seems to suggest that for muscle building
purposes there may be an advantage to consuming protein that is above the
generally recommended levels [Haub MD, 2002].
If we look at our current recommendation of 70-120 grams of protein per day
(on average) we see that we could meet the needs of a 220 pound man (100
kg*1.2 g protein =120 grams per day) and the needs of a 110 pound woman (50
kg*1.4 grams of protein = 70 grams of protein per day) while still falling within
the ranges of what scientist consider to be ‘high’ protein.
To answer the question, ‘how much protein do we need to build muscle?’, it
seems that the original recommendations from the late 1800’s of around 100
grams per day seem to be enough to meet the muscle building needs of most
adult men and women who are not using anabolic steroids. Not only this, but
even in people who are using steroids it is enough protein to allow for a
considerable amount of muscle growth!
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If we wanted to build a margin of error into this recommendation of 150%
overage (to account for excessively tall individuals with high lean body mass) we
still see an upper range of roughly 150 grams of protein per day at its highest
levels.
Finally, in order to assess our conclusions we can look to a study that analyzed
the results of several weight training studies and ‘pooled’ the results into one
BIG study.
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A BIG meta-analysis
In a paper published near the end of 2012, Naomi Cermack and colleagues
performed a random-effects meta-analysis of protein intake and how it relates
to the muscle building abilities of resistance training. This just means they
reviewed a bunch of studies on protein intake and muscle building.
They included data from 22 different research studies, combining all of the
people in the studies so they had data on 680 different people, effectively
turning 22 small studies into one big study on the muscle building effects of
protein.
All of the studies had to include a workout program that was longer than 6
weeks, and have people consuming either a high protein supplement or a high
protein diet.
The people in the studies were between 19 and 72 years of age, men and
women and all were in good health.
Of the 22 studies, 3 of them supplemented people with essential amino acids,
11 of them supplemented people with whey protein, 2 used dietary increases in
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protein, 1 used chocolate milk and the other 5 used some form of casein, soy or
milk.
All of the studies had people performing resistance exercise, with 8 of the
studies having people train 4-5 times per week, and the other 15 studies had
people training 2-3 times per week.
The longest study was 24 weeks long while the shortest was 6 weeks long, with
the average being about 12 weeks in length.
Individually, only 5 of the 23 studies found a significant effect of protein
supplementation. Interestingly 4 out of the 5 studies that found an effect from
protein also had high training volumes (2 studies were 4 times a week for 10
weeks, and two studies were 5 times a week for 12 weeks).
Now here is where it gets interesting, when the researchers pooled all the data
together (basically treating a bunch of little studies as one BIG study with over
600 people in it) they found that protein supplementation did in fact, cause a
significant increase in muscle mass.
When all combined together, the group of people consuming the protein
supplements gained about 1.5 pounds more lean mass than the non-protein
supplementing group! On average the non-supplemented groups gained about
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3.9 pounds of Lean Body Mass, while the protein groups on average gained
about 5.4 pounds of Lean Body Mass.
Of course, when you go back and look at the individual protein intake of each
individual study you find that the protein supplemented groups were rarely
consuming more than 120 grams of protein per day, while the non-protein
groups were in the lower end close to 70 grams per day.
In fact, when you add this large meta-analysis to our evidence it strengthens
our arguments that resistance training creates an ‘anabolic advantage’ to how
our body reacts to protein, but that this advantage is relatively small, and has
defined upper limits.
Now that we have a strong theoretical basis for the amount of protein that
seems to help promote muscle growth, the next question to consider is whether
or not there is a particular way in which we are supposed to ‘take’ this protein,
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or whether or not the anabolic advantage is stronger depending on when or how
the protein is ‘dosed’.
In other words we know there is a slight muscle building advantage to eating
more protein then is recommended by the RDA or RDI, but we do not know if
the timing of these protein meals makes a difference to how well, or how quickly
we can increase the size of our muscles.
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Protein and Meal Timing
One of the most common beliefs with protein is that it has to be consumed
every 2-3 hours, otherwise your body will become catabolic and begin eating
away at your muscle mass.
While this recommendation is certainly effective at increasing the amount of
protein you need to buy, it does not seem to be supported by scientific evidence.
Some of the original research on this topic was published in the early 1970s.
This research showed a better utilization of protein when the protein was given
in 4 doses of 15 grams per day, instead of 2 doses of 30 grams. Of course this
research was conducted in children aged 8 to 13, so it’s applicability to our
needs is questionable [Barja I, 1972].
In a very similar study conducted on college-aged men, it was shown that
protein is as well utilized when consumed only at lunch and dinner as when divided
evenly among the three major daily meals [Taylor, YSM, 1973].
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This same group also conducted a second study which illustrated that protein is as
well utilized when breakfast consists only of a glass of skim milk with the remaining
portion of the daily protein and energy intake supplied at lunch and dinner as when
it is provided in a complete lunch and dinner, and breakfast is omitted [Taylor, YSM,
1973].
Keep in mind that both of these studies used a measurement called Nitrogen
Balance, and were not measuring actual changes in Lean Body Mass, skeletal
muscle mass or things like protein synthesis. However, we can examine
research done in 2007 that did measure the effect of meal timing on Lean Body
Mass.
In a research paper published in the American Journal of Clinical Nutrition a
group of healthy men and women were asked to eat all of their daily calories in
either 1 meal or 3 meals for a period of 8 weeks [Stote KS, 2007].
Both experimental diets contained a slightly higher than normal protein
content, consisting of roughly 85 grams of protein, (which lands them right in
the 70-120 gram range I recommended earlier).
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These people either consumed all of their protein in one big meal or ate the
traditional breakfast, lunch, dinner, with each meal containing between 25-30
grams of protein.
At the end of the study, the researchers noted no difference in the lean body
mass of the subjects, illustrating that eating protein only once in a 24 hour
period for 8 weeks straight does not cause you to lose muscle mass (as long as
the protein content is high enough to meet your daily needs).
Eating protein only once in a 24 hour period does not cause you to lose muscle mass (as long as the protein
content is high enough to meet your daily needs).
So either eating all your protein in one meal does not increase your risk of
losing muscle, or the muscle loss was so slow it was undetectable after 8 weeks.
Either way, from the available data it seems as though whether you eat slightly
more protein less frequently, or less protein more frequently, it looks like you
are good no matter how you decide to eat your protein.
Research examining protein synthesis (as opposed to measuring changes in
muscle mass) agrees with this finding. Research examining what happens when
amino acids are provided constantly for 6 hours (supplied intravenously – like
an I.V. drip) has shown that muscle protein synthesis increases after about an
hour of amino acid availability, stays increased for about 90 minutes, then
returns back to normal levels for the remaining 4 hours, even when amino
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acids are still present at measureable levels in the blood [Bohe J 2001].
Based on this evidence there seems to be little reason to eat protein at a high
frequency, at least for men and women who are ‘active’ but not resistance
training. However, we do need to explore whether or not resistance training can
shorten or alter this protein synthesis refractory period.
Research published in 2009 by Moore et al illustrated that resistance training
did not increase the amount of protein that was ‘usable’ showing that the upper
limit of protein needed for maximal increases in protein synthesis was the same
in non-exercised vs exercised muscle (the amount of protein that provides
roughly 10 g of essential amino acids) However, the same amount of protein did
cause a slightly longer, and more prolonged anabolic response in resistance
trained versus non-resistance trained individuals [Moore et al, 2009].
As mentioned earlier, it seems that resistance training creates an anabolic
advantage, where the same amount of ingested protein causes a slightly longer
anabolic response in resistance trained individuals [Pennings B, 2001]. Since
this anabolic effect is prolonged rather than overly heightened, it may mean
that the optimal protein timing for resistance-trained individuals may actually
be slightly less frequent then it is for non-trained individuals, possibly as long
as 6 hours or more in between protein feedings [Atherton PJ, 2012].
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Post-Workout Protein
When it comes to protein and muscle mass, one of the most commonly held
beliefs in the sport nutrition industry is that you need to eat protein after your
workouts to fuel the muscle building process. Even people who do not believe in
the merits of a high protein diet will still be sure to eat protein immediately after
their workouts.
On the surface this theory seems to make sense. Since chronic and consistent
weight-training workouts can stimulate muscle growth, and muscles are built of
protein, and you want more muscle, I can see why some people think that
adding more protein to the mix might enhance the muscle building effect.
The idea that there is a magical window of time immediately after the workout
where protein MUST be taken is what doesn’t make sense to me. Somehow,
people have been lead to believe that they will lose the muscle building benefits
of the workout if they don’t take a protein supplement immediately after their
workout.
It is this belief that leads me to my next question “Do I need to eat (or drink)
protein immediately after my workout to make my muscles grow?”, but to
answer this, I must first answer the question “Can my muscles grow without
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taking protein immediately after my workout?”, and the answer to this second
question seems to be “yes”.
In a study published in 2007, people performed weight-training exercises for 12
weeks while taking one of the following four supplements immediately after
their workout
a) Protein
b) Protein plus colostrum
c) Protein plus creatine
d) Creatine plus colostrum
The two groups of people who were taking post-workout protein only gained 2
pounds of muscle in 12 weeks, while the creatine groups gained about five
pounds in 12 weeks. So in this trial, creatine had a much more potent muscle
building effect than a post-workout protein supplement, but none of the results
were outside of our 2 to 5 pound baseline we came up with at the beginning of
this book [Kerksick CM, 2007].
What you need to know about this study: The average protein intake for all groups combined was 165
grams of protein per day, well above our range of 70-‐120 grams. This study was funded by General
Nutrition Centers Inc. (GNC)
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In another trial published in 2000, scientists studied men who took part in a
resistance-training program for 10 weeks. During the study these men also took
a post-workout supplement containing either 40 grams of whey protein or 40
grams of whey protein with an added 5grams of L-glutamine and an extra 3
grams of Branched Chain Amino Acids (BCAAs).
Note: L-glutamine and BCAA’s are popular muscle building supplements that have
been theorized to be beneficial for gaining muscle. They have been found to have
beneficial effects on short-term protein synthesis measures but have failed to
show any measurable results changes in actual lean body mass measurements.
At the end of the trial the whey protein group gained an insignificant half-
pound of muscle, and the protein plus extras (BCAA’s and Glutamine) gained
an uninspiring pound and a half. Considering that the people in this study were
weight training for 10 weeks, these were not very impressive results [Colker CM,
2000].
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The Research That Started All the Confusion
When it comes to the importance of ‘nutrient timing’ it seems that this popular
notion started with a research paper that was published in 2001 that showed
that when it comes to protein – ‘timing is everything’.
If you read any popular fitness/nutrition publications or websites, you’ll see
this research quoted everywhere! Most of the articles you read in magazines or
online usually quote the same study published in the Journal of Physiology.
The Journal of Physiology is a very reputable journal, so I figured this study
must be a pretty solid piece of evidence supporting all the chatter about the
specific timing of post workout protein supplementation. Obviously I had to see
this research paper myself and see what it said.
When I finally tracked this study down I was surprised to learn that the
subjects in this trial were older men in their 70’s, and the post-workout protein
supplement only contained 10 grams of protein! While this is by no means a
‘design flaw’, it is very unethical for the people quoting this study to omit these
small details.
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10 grams of protein is a far cry from the protein mega doses that are currently
being promoted by all the latest nutrition and fitness gurus, and the nutritional
needs of men in their 70’s is going to be unique from those of younger men
attempting to maximize their muscle mass. And, the inconsistencies between
the study and the current fitness industry dogma don’t stop there.
In this study, the older men participated in a weight-training program 3 days a
week, for 12 weeks. After their weight training they drank a supplement
containing 10 grams of protein and 7 grams of carbs either immediately or 2
hours after their workout.
After 12 weeks the group consuming their protein immediately after their
exercise gained two pounds of lean mass, while the group who took their
protein 2 hours after their workout somehow managed to lose two pounds of
lean mass [Esmarck B, 2001].
In my personal opinion, 70-year-old men gaining two pounds of lean mass after
12 weeks of working out is hardly reason enough for me to start accepting the
idea of large amounts of post-workout protein being needed in younger or
middle aged men. Not to mention that this is only a significant finding because
the non-protein group somehow managed to lose 2 pounds of lean mass, which
is very surprising given their weight-training program (I’d even go so far as to
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say this specific result is fishy, and may be a phenomenon related only to this
age group).
Most likely, these findings are due to either poor study designs (all of their data
was rounded to the nearest whole pound) or data collection errors. In fact, I am
willing to bet that if this study were to be redone using our target population of
people aged 18 to 55 we wouldn’t find any significant results at all.
What you need to know about this study: The supplement in this study was ‘JogMate Protein’ and is
produced by a company called Otsuka Pharmaceuticals. The study was funded by Otsuka Pharmaceuticals.
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Post-Workout Protein – What’s Really Happening?
As it turns out, scientists were correct when they said that post workout
nutrition is vitally important to the muscle building process – the issue was the
definition of ‘post-workout’.
In recent research performed at McMaster University in Hamilton, Ontario
Canada in conjunction with the University of Nottingham in England, it was
found that the first meal after a workout is extremely important to many
markers of muscle growth. They also found that this meal could be as much as
24 hours AFTER a workout [Burd NA, 2011].
In this study 15 recreationally active young men with previous resistance
training experience took part in a study where they either:
A) Consumed a drink containing 15 grams of protein.
B) Completed a weight training workout, then consumed a drink containing
15 grams of protein 24 hours after the completion of their workout.
The researchers found that despite the fact that their protein feeding was 24
hours AFTER their workout, the subjects still found elevated changes in
markers of muscle growth after protocol B when compared to protocol A.
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Absolute changes in the fractional synthetic rate of myofibriliar proteins (a
marker of muscle growth) were elevated higher after protocol B compared to
protocol A. In other words, if the results of protocol A were representative of
what happens normally when you just eat some protein, then protocol B
illustrated that resistance training heightens this anabolic response, even if the
workout occurred 24 hours before the protein feeding.
The researchers also found significant increases in many of the molecular
markers of muscle growth such as mTOR and 4E-BP1.
So while this was not a training study (it wasn’t long term) and it didn’t
measure actual changes in muscle mass, it did measure the main surrogate
endpoints that most people use to support the need for post workout
nutrition/protein.
This study also illustrates the theory of anabolic advantage – eating protein
doesn’t make your workouts more ‘anabolic’, working out makes your protein
intake more anabolic by increasing the anabolic response to protein feedings.
Therefore, as the results of this study show, it is conceivable to say that EVERY
meal you eat is a post-workout meal considering your workouts ‘prime’ your
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muscles to be more responsive to the anabolic effect of eating protein. And that
this effect can be measured up to 24 hours after the workout!
So it is reasonable to suggest that the most important muscle building meal is
the meal you eat after your workout – but that this meal could be as far as 24
hours after your actual workout!
This next study is another excellent example of every meal being ‘anabolic’
when you are weight training.
Most research conducted on the muscle building effects of post-workout protein
have one interesting thing in common – the subjects are almost always fasted at
the beginning of the study.
Typically the people in the study would show up to the lab after an overnight
fast, then they would fast for an additional hour or two while the study is being
set up. After this they would complete a workout usually doing a grueling leg
workout of 8 sets of 8-10 reps using 80% of their 1 rep max on leg press. After
the workout (which takes anywhere from 20-45 minutes) they are then given
their post-workout drink either immediately or within an hour, and then they
sit quietly while the researcher takes measurements for 3-4 hours.
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So in almost all of these studies the time between the subject’s last meal, and
when they are given their post-workout protein can be anywhere from 12 to 18
hours, and in almost all of these studies it was found that protein synthesis
after a workout is higher with the addition of post-workout protein than without
it, at least for the 2-3 hours that they typically measure.
However, one group of researchers were curious if the pre-workout fasting was
a confounder in these studies – If the large spike in protein synthesis found
with post-workout protein was a consequence of the fact that the subjects have
been fasting. Or, more correctly they hypothesized that the large increase in
protein synthesis that occurs when the people in these studies ate protein after
their workout only occurred because they were at the end of a 12 to 18 hour
fast.
So they flipped the design of a typical post-workout protein study.
They had a group of men eat a standard dinner, then go to sleep. When they
woke up they had a standardized breakfast, containing about 500 calories and
30-50 grams of protein (depending on the subject). Then they waited for about
one and a half hours then they exercised 1 leg with 8 sets of 10 reps of both leg
extensions and leg curls at 70% of their 1 rep max, with 2 minutes rest in
between each set. The other leg did no exercise at all.
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Once they were done their workout they had their protein synthesis levels
measured in both legs, then they fasted for 6 hours and had their protein
synthesis levels measured again.
Surprisingly, after six hours of fasting the non-exercised leg had levels of
protein synthesis that would be expected after a large protein meal and the
exercised leg had a rate of mixed muscle protein synthesis that was 20% higher
than the non-exercised leg. The levels reached were the same levels found in
studies where people are fed protein directly after their workouts, showing that
resistance exercises changes the way your body uses protein, directing it more
towards muscle metabolism, and that this occurs when food is followed by a
workout to a similar extent as when the workout is followed by food [Witard OC,
2009].
These last two studies clearly show that resistance exercise substantially
stimulates mixed muscle protein synthesis and create an anabolic response to
protein feedings. This effect is consistent where food intake occurs before
resistance exercise or when food intake occurs after exercise.
The bottom line is that the right weight training with the right intensity and
effort does sensitize the muscles to the anabolic effect of dietary protein, it’s
important to note that this result remains for as long as 24 hours. Therefore, it
seems that protein sufficiency, rather than timing of intake, is the more
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important aspect to successful muscle growth. It seems to make little difference
whether protein is given pre-, during or post-exercise.
Another interesting finding about the relationship between exercise and protein
is that exercise may increase the amount of time that dietary protein can
increase protein synthesis. Studies have found that simply feeding protein can
increase markers of protein synthesis for about 90 minutes, after which
muscles seem to become unresponsive to additional stimulation by amino
acids. However, when amino acids are fed after a resistance training work out
amino acids are able to increase muscle protein synthesis for up to 5 hours
[Moore DR 2009].
The main effect of post-workout protein may be that the muscle is some how
more sensitized to the anabolic effects of amino acids, and while there isn’t a
greater increase in protein synthesis, the elevation in protein synthesis does
seem to last longer (5 hours) then it does when feeding protein with no exercise
(90 minutes).
The key thing to remember is that muscle growth is an extremely slow process,
with most research finding increases that are much lower than 1 pound per
month. Muscle growth that occurs over a 12-week period is the result of the
cumulative effects of dozens of workouts and potentially hundreds of meals,
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with each workout sensitizing the body to the very small anabolic affect of each
protein containing meal.
In other words, to put it in extremely simple terms, eating protein doesn’t make
your workouts build muscle, working out makes eating protein build muscle.
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Very High Dose Protein Fails to Impress Again
In yet another research study examining the effects of protein post-workout,
young healthy men were placed in one of two groups. One group received 10
grams of creatine with 75 grams of dextrose (dextrose is a form of sugar)
immediately post-workout, while the other group received 10 grams of milk
protein plus 75 grams of sugar.
After 8 weeks of a very impressive weight training program the protein group
gained just under 6 pound of lean mass (again, just a bit above our base line of
2-5 pounds).
Interestingly, in this research the creatine group gained almost 9 pounds,
which was much more than the protein group. It is also important to note that
because of the way the statistics were run in this trial the difference between 5
pounds and 9 pounds was not significant.
What this research shows is that even without post-workout protein, the group
taking creatine after their workouts gained more lean mass than the group
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taking protein after their workouts. [Tarnopolsky MA, 2001] (Another example
of creatine performing much better than protein as a post-workout supplement).
As you can see, when we investigate research on post-workout protein that
measures changes in muscle size and weight (as opposed to surrogate
endpoints like Amino acids movement) we see very little evidence to support the
idea that immediately post-workout protein is essential to increases in muscle
weight…it may help, but it is not essential.
What you need to know about this study: Both groups consumed an average amount of protein daily that was
slightly more than 120 grams (125 and 131 grams). This study was funded by MuscleTech Research and
Development, Inc.
Based on this review, I see no reason to AVOID post-workout protein, and if
possible it seems like a logical time to eat protein, but also does not seem like
you need to overly stress if you miss, or have to delay, the meal to a later time.
Bottom line – There may be some benefit, but it is also not an essential
component of your muscle building process.
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The Need for Protein – An Alternative Hypothesis
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When discussing muscle growth it is important to note that there are
actually two different types of muscle growth.
1) Juvenile Muscle Growth
2) Work Induced Muscle Growth
This little known fact could be responsible for many of the high protein success
stories you read about on-line and in magazines.
When you take a close look at these claims, whether they are before and after
testimonials for various diets or workout programs, of if they are articles about
athletes and actors, you will typically find a common theme.
Upon close inspection you will find that most of the people in question are
typically men who are in their late teens and early twenties.
This is note worthy because, for a brief period of your life, you are able to
harness both types of muscle growth.
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Juvenile Muscle Growth
When you are young your body is undergoing a type of growth called ‘juvenile
growth’. Your muscles are growing at an unparalleled rate while your body
grows both in height and maturity.
Consider that after birth, the human body mass doubles in the first 5 months,
then again in the next 30 months, then again in the next 6 years! However, as
we become adults our body mass growth rate eventually reaches zero, with the
exception of the continuing gain in fat mass (for people who live in
environments with enough food to support fat gains) [Lui et al 2011]
During and after puberty, human bodies take on their more adult form, and
this includes a pronounced increase in skeletal muscle mass.
As an example, in the growth chart below provided by the National Institute of
Health Statistics, you will see that the average expected weight gain for an adult
male from the ages 16 to 20 is roughly 20 pounds.
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Now, this growth isn’t ALL muscle, however a good chunk of it certain will be.
After all, we don’t call it ‘filling out’ without reason.
It is this type of muscle growth that is very sensitive to nutrient status,
specifically calorie and protein intake. Research suggests that when we are
young we have a high degree of Anabolic Sensitivity – Meaning our bodies react
to eating protein by increasing the anabolic activity in our muscles – This is in
line with the belief that more protein means more muscle (at least in the
young). It also helps to explain why poorly fed children tend to be smaller than
normally fed children. And it is also why re-‐feeding a group of poorly fed
children will quickly return them to normal ranges of muscle mass. However,
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while overfeeding children can accelerate growth until they have caught up with
roughly where they should be, overfeeding cannot prevent the eventual
stoppage of juvenile growth. Forced overfeeding does accelerate weight gain
however as we age more and more of the weight gain is attributed to fat rather
than muscle [Victoria CG, 2008].
Juvenile growth continues until after you’ve reached full skeletal maturity
(when your bones fuse and stop growing), this typically happens when you’re a
young adult in your early twenties. Once you have reached your full mature
size, this high-‐speed nutrient dependent growth comes screeching to a halt. In
other words, from a biological point of view you are simply done growing.
The stop of Juvenile growth happens in a coordinated fashion leading to
speculation that there is a complex growth-limiting program in our genetics
that turns on in multiple organs (including skeletal muscle) once we hit our
‘adult size’. [Lui and Baron 2011].
To be clear, it’s not just a change in testosterone or growth hormone that
causes juvenile growth to slow [Finkelstein JW 1972; Guistina A 1998]. It is
more than likely a concentrated complex of multiple genetically inherited
factors that decide both the amount of muscle you naturally carry as an adult,
and the amount you can increase this muscle’s size by resistance training – so
we can’t just fix it by taking a supplement or changing how we eat.
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This genetic limit is also thought to be inheritable. In a study of arm strength
and size in 36 male twins it was found that both strength and size showed a
high degree of inheritability [Thomis MA, 1998]. Simply put, if your parents,
brothers and sisters are all well muscled, chances are you have the potential to
be well muscled too.
So while under eating during Juvenile growth will stunt growth to some extent,
overeating will not prevent the decline of juvenile muscle growth. When we
move into our advanced years we become more and more resistant to the
anabolic effects of protein. So even though our ‘basal’ levels of protein synthesis
are no different, our response to amino acid feedings is greatly diminished
[Cuthbertson D, 2005].
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Work Induced Muscle Growth
Work induced growth is the second type of muscle growth. This type of muscle
growth is caused by placing ‘mechanical stress’ (such as lifting weights) on your
muscles, and is driving the incorporation of satellite cells into existing muscle
fibers.
The explanation behind Work Induced Muscle Growth is as follows: As you
stress your muscles and challenge them by making them contract against some
form of resistance, they respond by adapting to become stronger and larger.
Work induced muscle growth is much slower than juvenile muscle growth and
nutrient status (what, or how much you eat) has far less influence over this
type of growth.
In other words, once you are a full grown adult, it is the work you do in the gym
that determines how much more your muscles will grow! (not some magical
diet).
Work Induced Muscle Growth is tied to protein intake in that it seems to
‘sensitize’ your body to the anabolic affects of protein intake. In other words,
during Juvenille Muscle Growth eating protein alone is enough to cause or
allow muscle growth. Once Juvenille Muscle Growth is complete, eating protein
is enough to maintain muscle mass, but not enough to cause measurable
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increase in muscle mass.
Mechanical work such as weight lifting alters this response by increasing the
anabolic sensitivity of your muscles such that the anabolic response is higher
and longer, creating an anabolic effect that, if continued over weeks and
months should create a noticeable increase in muscle size.
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Why You Grow So Quickly When You’re Young
After puberty, sex steroids like Testosterone are at their highest, and other
hormones such as Growth Hormone are also elevated and you have a full
compliment of satellite cells that are fully capable of incorporating into muscle
fibers. And while we have not been able to identify any one hormone as the ‘key’
to muscle building, the important thing about the period after puberty is that
almost ALL anabolic hormones are elevated. In other words, the human body is
in a unique state when work induced AND juvenile growth can happen at the
same time. This typically happens in the early to mid twenties.
This phenomenon explains why young (18-‐25 year old) men with little or no
training experience are always the ones who see the most impressive weight
gain results in clinical research trials (and I suspect this is also the reason why
this is the type of person who is always asked to take part in muscle building
research studies). This is also the reason why most contact-sport athletes hit
their prime between 25 and 30 years of age.
The human body simply responds better to resistance exercise at this age. In
fact, when comparing the Fractional Synthetic Rate response to resistance
training, you will notice that there is a blunted response in men over 65 at
almost all exercise intensities.
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(Older muscle seems to have difficulty responding to
exercise in the same manner as young muscle)
I think this overlapping effect of juvenile and work induced muscle growth is
the reason today’s workout advice confuses so many of us.
In research comparing the effects of exercise between a group of men aged 20-
35 with those aged 60-75 a number of startling findings were uncovered. The
most expected finding was that while following the exact same 3 day per week
workout program (training legs 3x per week) lasting 16 weeks, the young men
gained more lean mass, and more muscle size than the older men. The
surprising part was what happened next.
After the 16 week training period the subjects in this study were then divided
into one of three groups:
1. A detraining group – this group did no exercise at all
2. A low volume group – This group only trained once per week. Doing 3
sets per exercise.
3. A super-low volume group – this group trained once per week, and only
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did one set per exercise.
This new protocol was continued for an additional 32 weeks while scientists
tracked the changes in the subjects muscle mass over time.
In the young men there was a clear dose-response to exercise that continued
after their initial muscle gain. They were able to continue adding muscle mass
with 1/3 of the volume, they could maintain their muscle mass training once
per week with a greatly reduced volume per workout, and only lost muscle
when they were completely detrained.
On the other hand, the older men weren’t so lucky. There was no dose response
in the older group. All three groups lost significant muscle mass in the older
men.
So not only did the older men put on much less muscle then their younger
counterparts, but they were also not able to maintain that new muscle mass
when asked to do a reduced volume of training [Bickel CS, 2011].
In fact, previous research has shown that it would take up to 4 months of
training for the muscle of older adults to reach the same size as UNTRAINED
men 40 years younger in age [Kosek DJ 2006].
The cold hard truth is that if you are older than 30 or you’ve been training for
more than 10 years your days of gaining fifteen pounds of muscle over a
summer are long gone. In fact, at this age you most likely NEED resistance
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training in order to have an anabolic response to protein intake.
For advanced trainers, we are left with nothing but hard work and proper
recovery to stimulate our muscles to grow, and even when they do grow, they
are going to grow very slowly.
Interestingly, these facts all lead to the suggestion that since muscle growth is
slower in older men and women, and that weight training in and of itself is
actually a protein-conserving stimulus it is logical to suggest that weight
training actually decreases the dietary protein needs of an individual, especially
a person who is no longer experiencing juvenile muscle growth [Phillips, SM
2006; Hartman JW 2006]
In fact, it seems as though as we age it is weight training that keeps our body
primed to use protein for muscle growth. Without weight training the anabolic
sensitivity of our muscles would slowly move towards anabolic resistance which
is a dampened response to eating protein.
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What happens when we don’t workout
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Based on the research reviewed so far it’s become apparent that the muscle
building effect of resistance training seems to come from it’s ability to sensitize your
muscles to protein intake.
The basic premise being a person who weight trains would have an ‘anabolic
advantage’ over the person who does not. Simply put, if each person were given 30
grams of protein, the weight training persons muscle would respond with a longer,
higher anabolic response.
To examine the accuracy of the concept of ‘anabolic advantage’ we can look to the
research studying something called 'Disuse atrophy'. Disuse atrophy is when a
muscle shrinks in size as a result of not being used or stressed. It can occur quickly -‐
think of an arm in a cast -‐ or slowly – someone who used to workout then stops.
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In this line of research it’s been found that part of the atrophy of shrinking of
muscles occurs because they have become "anabolic resistant". Anabolic Resistant
means the physiology of the muscles change from being sensitive to the anabolic
affects of eating protein to being resistant to the anabolic affects of protein and
amino acids.
In classic cases of disuse atrophy the anabolic resistance can mean a 45% drop in
whole body protein synthesis in response to a protein containing meal [Greenleaf JE
1982]. In fact, even 14 days of bed-‐rest can cause an almost 50% decrease in rates of
protein synthesis in otherwise healthy individuals [Fernando AA, 1996].
Interestingly, this drop in anabolic sensitivity seems to start to occur after about 8
days of non-‐use. Therefore sometime between 8 and 14 days of non-‐use, MAJOR
things start to happen to the physiology of your muscles where you see a reduced
muscle volume, decreased levels of overall protein synthesis and a blunted response
to eating protein or amino acids [Brocca L, 2012].
This resistance only seems to be reversed by exercise as feeding amino acids or
protein to people undergoing prolonged bed rest doesn't help prevent the muscle
loss that occurs. In fact, some researchers have found that if you feed amino acids to
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people who are bed ridden (and obvious not exercising) they could actually see an
INCREASED rate of muscle volume LOSS [Brooks N 2008; Lemoine KL 2009].
The only thing that does prevent muscle loss during disuse is resistance training,
and this works especially well when resistance training is combined with protein or
amino acids. This means that the muscle building effects of eating protein can only
happen if you are also resistance training.
This provides strong evidence for the Anabolic Advantage theory – wich proposes
that the way resistance training ‘works’ to build muscle is by sensitizing muscle to
the potential anabolic affects of eating protein. In essence it is your workouts that
make eating protein ‘work’.
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Maybe it’s all a Race…
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The most confusing thing about Muscle Growth is that in almost every
research study examining the effect of 2-4 months of resistance training and
muscle growth we see a positive result. However, whenever those results are
extrapolated into the long-term the results flatten. In other words, the amount
of muscle gained in the first 4-6 months cannot be expected to continue over
years. If this were true all men and women who have been training for more
than 10-15 years should be carrying hundreds of pounds of extra muscle, and
this is clearly not the case.
Consider the following – Some studies have found that resistance training can
cause a muscle to increase in size at a rate of about 0.15% (that’s 15% of 1%)
per day. Now assuming (and it is only an assumption) that you could cause ALL
of the skeletal muscle in your body to increase at this rate we can quickly see
an example go from appearing very possible to obviously impossible.
Using the basic equation for compound interest we see how the concept of
constant muscle growth quickly falls apart.
Using an example of an average 5’10” man who has roughly 140 pounds of lean
body mass we know that he would have about 70 pounds of skeletal muscle
mass (skeletal muscle is typically about 50% of lean body mass).
Under these assumptions our man could gain about 7 pounds of muscle in 8
weeks if he were to gain at a rate of 0.15% per day. Seven pounds of muscle in
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two months time would be very impressive, however to the average person it
would also seem like a ‘realistic’ amount of muscle growth. Using the exact
same equation we find that he should also be able to gain about 50 pounds in a
year and almost 300 pounds of muscle in three years if this rate remains
unchanged. Now obviously this is a gross over simplification of how the body
works, but the fact remains – there is an obvious and powerfully controlled
genetic upper limit to how much muscle we can realistically build on a given
frame, regardless of our workouts or protein intake.
This concept is supported by the research on satellite cells, which illustrates
that the ability of satellite cells to incorporate into muscles diminished with
time and it agrees with other research showing that muscle has limitations to
the amount of size it can build [Young VR, 1974].
It is also supported by the research on compensatory hypertrophy and the
research on catch up growth. In all of these studies, when people are
undergoing ‘catch up’ growth (undernourished children who are being re-fed)
they go through a period of highly accelerated muscle growth, but only until the
time where they have caught up to roughly the size that they should be, given
their age and their height.
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Similar results occur in studies looking at people in casts. When a broken limb
(arm or leg) has been immobilized for several weeks it will undergo a significant
amount of muscle loss, but with rehab exercises you can quickly gain back
muscle to the point where the you can’t even tell the arm or leg was once
broken, or that any muscle loss ever occurred.
In fact, this concept is even supported in research studying the muscle growth
potential in high-level bodybuilders eating over 6,000 calories per day,
consuming over 300 grams of protein per day and taking anabolic steroids.
In this study, highly competitive bodybuilders took part in a 24 week study
where researchers examined the growth of their upper arms before and after 24
weeks of a high-level weight training program. After finding minimal results in
these high level bodybuilders compared to non-body builder controls it was
concluded that once a high degree of muscularity has been achieved, further
improvements are minimal [Always SE, 1992].
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This leads to the following hypothesis:
If there is an upper limit to how much muscle you can build then it is possible
that all of the muscle building research is actually illustrating different speeds
or rates of muscle growth but not actually MORE growth. In other words, you
may only be able to gain around 8 pounds of muscle, but you may be able to
gain it slightly faster by taking protein before or after your workouts, or by
increasing your protein intake into or beyond the 90-120 grams range.
It could simply be that protein may be able to slightly improve the rate at which
you build muscle (as can sleep, recovery and the quality of your workouts) but
it is highly unlikely that increased dietary protein, even to ultra-high levels is
able to alter the upper-limit to how much muscle you can actually build and
carry on your given frame with your specific genetic predetermined limits. This
theory would help explain why most research finds similar muscle growth in
similar time frames, despite varying workout regimens and nutritional
interventions.
The bottom line is that this theory suggests that while there is a genetically
defined upper limit to the amount of muscle growth you can carry given your
frame, body type and physiology, the rate at which you obtain this muscle may
be influenced by dietary factors such as protein, as well as your ability to rest,
recover and by the quality of your workout program.
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Once this limit has been reached, a high-protein diet would probably become
unnecessary. This suggests that our range of 70-120 grams is ideal for muscle
growth, after which a more conservative number closer to the RDI could be use
for the maintenance of muscle size [Millward DJ 1990].
This graph illustrates the basic 4 phases of muscle size. Protein intake, physical
activity and overall health and nutritional status can move a person from
dangerously low muscle mass all the way into compensatory hypertrophy. Lean
body mass may enter the area of pathological growth transiently (for a short
period of time) due to periods of massive overeating or large increases in weight
training frequency and volume. However, this is only a transient increase.
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Muscles only enter ‘pathological growth’ chronically when an underlying disease
state is present.
*Please note this graph does not account for the use of anabolic steroids, other
growth enhancing drugs or rare genetic anomalies).
Extra protein isn’t going to move you into ‘pathological growth’ but the
combination of extra protein and chronic resistance training may help you
reach your top levels of compensatory hypertrophy faster than you would have
without the extra protein. And that is the whole point of eating more protein
when you’re consistently weight training.
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Conclusions
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Conclusions
When you look at all the available research, instead of one single study
you begin to see the big picture: Human muscles are equipped with
mechanisms that can regulate both short- and long-term changes in protein
metabolism. Based on this there is an obvious limit to how much a person can
increase the size of their muscles without the use of pharmaceuticals (steroids),
and there may even be another limit that cannot be breached even with high
doses of anabolic steroids.
From the available research it is easy to say that a full grown adult can expect
to gain a conservative estimate of between 2 to 5 pounds of lean mass in 2 to 4
months by resistance training. There is evidence to suggest that you might be
able to gain about 7 - 8 pounds of muscle depending on your genetic potential
for muscle growth, your height, training status and a whole host of additional
factors, some identified by science, and some are still a mystery.
Interestingly, research suggests that an elevated protein intake of between 70
and 120 grams per day does not seem to allow you to gain the more than this 2-
5 pounds of muscle mass, however it may allow you to gain them faster than
you would with a protein intake closer to the recommended 60 grams of protein
per day.
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These results lead me to say that protein still has an extremely important role
in everyone's nutrition plan, and is an essential nutrient that is obviously
important for building and repairing muscles.
In fact, from my understanding of the research it makes sense to try and
consume above the current recommended amounts, aiming for around 70-120
grams of protein per day, and possibly going as high as 150 grams depending
on your body weight and current calorie intake and exercise levels. However, it
also appears evident from the available research that once a certain amount of
muscle size has been gained, continuing to increase your protein intake will not
allow for further increases in muscle size (this is where an increase in weight
training volume or intensity is required or advanced supplementation with
muscle building agents such as creatine).
Even once near maximal increases in muscle mass have been reached, I would
still people on a hypocaloric diet and people taking part in excessive amounts of
exercise (athletes or people combining endurance exercise with resistance
training) aim for the upper end of this scale.
In fact, if I were forced to give a more specific protein recommendation then I
would have to use the recommendations from the 1800s. Back in the 1890’s
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leading researchers of the time studied the diets of undergraduate boat crews (I.E.
young, athletic rich guys) and showed that during intensive training they had high
intakes of protein, -‐ about 155 grams of protein per day.
These findings became the ’Atwater standards’ (named after the head researcher), a
set of protein recommendations based on degree of daily muscular work being done
in any given day.
These standards proposed that men undertaking light to moderate workloads
eating between 112 and 125 grams of protein per day. But that men undergoing
extreme or heavy workloads increase their protein intake to 150 grams per day.
Based on this data I will also say that while 70-120 grams seems ideal for
periods when muscle size is increasing. If you are undertaking an excessive
amount of exercise above and beyond traditional weigh training then possibly
think of increasing this intake briefly to ~150 grams. However, it seems that
due to the body’s protein needs and the protein-conserving nature of resistance
training an intake of protein closer to the RDI (around 60 grams) would likely
be enough to maintain muscle size, especially in a person who is well
conditioned through resistance training. Possible exceptions to this could be the
elderly, or people on long-term calorie restricted diets.
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If a protein containing meal is available post-workout it makes sense to take
advantage of this timing, however if protein is not available I would not be too
concerned seeing as the evidence is fairly clear that muscles hold on to the
anabolic sensitizing effect of a workout for at least 24 hours after a workout. So
I would aim to have a ‘post-workout’ dose of protein within a 24-hour period
after the completion of any workout.
If needed, protein powders can be used to supplement the diet for people who
have difficulty reaching their desired protein intake with food, however the
same can be accomplished with foods. The benefit of protein powder comes
from both the taste (they’ve come a long way since the 1980’s) and convenience.
And, as I have said before, while I do not see protein supplements to be
superior to food in anyway, I also do not see them to be drastically worse. In
fact, I would go so far as to say that protein powder has become exactly what it
was always meant to be - an optional supplement to a food based diet.
So supplementing with protein is fine, as long as you acknowledge that you will
not get a ‘dose response’. In other words it is not as easy as ‘the more protein
you eat, the more muscle you have’.
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The bottom line is as long as you consistently consume an adequate amount of
protein on a regular basis, whether its 1 large serving or 5 to 6 small servings
per day, you will have all the protein you need for your muscles to grow.
Right now, I feel confident in saying ‘if you want to build muscle, try to eat
between 70-120 grams of protein per day, take part in a consistent weigh training
program with a high amount of effort, but that’s about it. If post workout protein
is available I don’t think it will hurt your gains, but I do think that the
effectiveness is overhyped, and most likely diminishes with training status.
The good news is that this means that if you are interested in gaining muscle,
you can concentrate on the real hero behind your muscle gaining, and that is
you and your workouts. The amount of protein you eat is important to the
process, but the amounts needed for muscle growth are both reasonable and
attainable for most people following a diet that includes some forms of meat and
dairy.
Most importantly, outside of your height and genetics it is the quality of your
workouts that will determine how much muscle you are able to add and keep
on your body.
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I also do not see how all people can be recommended the same pattern of
protein intake. The concept that the mTOR pathway has a ‘refractory period’
where it cannot be stimulated despite the presence of high amounts of protein
makes me theorize that not only are multiple protein meals throughout the day
ineffective at further stimulating muscle protein synthesis, but they may
actually be detrimental in the long term do to their ability to increase rates of
overall protein oxidation.
Instead, the theoretical concept that one or two large protein meals per day,
spread 8-12 hours apart may be ideal. We know that the refractory period lasts
at least 4-5 hours, because we’ve measured it to last for 4-5 hours, however to
date we have no scientifically validated the time point at which mTOR is once
again prepared to be activated. It may be at exactly 5 hours plus one minute, or
it may be much, much longer.
Secondly, while it seems that mTOR is maximally stimulated with a protein
does of 20-40 grams of protein (depending on the protein source) it does not
mean that protein above this level are ‘wasted’. While not stimulatory, they can
still serve as the ‘building blocks’ for the protein synthesis that is occurring
inside your muscles. They also serve to lower the rates of protein breakdown in
between meals.
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So while 20-40 grams of protein, 3 to 4 times a day is the most well accepted
suggestion for protein intake in most bodybuilding circles. 40-70 grams twice a
day or even 70-120 grams once per day are also intriguing options as they allow
for large increases in amino acid levels, followed by several hours of a slow
transient release of amino acids into the blood stream (5-‐7 grams per hour) and
then finally a period of decreased amino acid availability that would allow a muscle
to regain its ‘sensitivity’ to the anabolic effect of amino acids.
My Best Recommendation
Probably the very best recommendations I can give is as long as you are eating
meals with a wide variety of foods you should be able to reach the 70-120 gram
target fairly easily (the average intake in North America is already around 90
grams). For times when training volume is dramatically increased (a sudden
increase in training volume or frequency, or inclusion of non-weight training
exercise like running or athletics) it may be advisable to increase your protein
to as high as 150 grams per day. For times when you are not actively trying to
gain muscle, 60 grams of protein per day may suffice, however for the elderly or
people on a long-term calorie restricted diet, intakes higher than 60 grams may
be warranted.
From the available research it becomes clear that the biggest muscle building
benefit of eating protein is only truly present when an individual is resistance
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training. It is the resistance training that makes the extra protein build your
muscles not the other way around.
So the true benefit of the combination of resistance training and protein intake
is the ‘anabolic advantage’ that resistance training creates – sensitizing your
muscles to the potential anabolic affects of protein intake.
This is why total protein intake becomes much more important than when or
how this protein is consumed for people who are doing regular resistance
training.
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What I DO NOT Recommend
Please note that I have not given recommendations as a percentage of your daily
calories or as a percentage of your body weight. This is because neither of these
equations have ever made any sense to me.
Take for instance, the idea of eating 1 gram of protein per pound of body
weight. If a man weighs 180 pounds at 15% body fat when you exclude the
weight of his fat he actually has 153 pounds of lean mass. If he eats 180 grams
of protein, then he is actually eating 1.17 grams per pound lean body mass
assuming your fat cells do not need any measurable amounts of protein.
Now if over the next year or two this particular man happens to gain weight at a
rate of 20 pounds per year (difficult, but not impossible to do) then after two
years he would weigh 220 pounds. So now he should be eating 220 grams of
protein per day by this logic.
But what if the weight he gained was entirely body fat? He would be 220
pounds with approx 30% body fat and would still have 153 pounds of LEAN
mass. So now he is eating 1.43 grams of protein per pound of lean body mass.
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It doesn’t make sense that his protein requirement increased by 40 grams per
day if the only thing that changed was the amount of fat on his body.
Another example of a confusing protein recommendation is eating a certain
percentage of your calories as protein. If a person who eats 2000 calories
follows the recommendation of eating 15% of their calories as protein this would
mean they would eat 300 calories from protein, or about 75 grams of protein
(each gram of protein contains approximately 4 calories).
Now if this same person starts to eat 4000 calories per day, and still follows the
recommendation of eating 15% of calories form protein they are now eating 150
grams of protein per day. Again, I see no logical reason why doubling your
calorie intake would cause a need for a doubling of protein intake.
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Final thoughts on Protein
For the purpose of building muscle mass I think the goal should be a general
recommendation of 70-120 grams of protein per day, and this should be an
average intake. As long as you average around 70-120 grams per day you could
be lower on some days and slightly higher on others, but muscle growth will
still occur.
I have also explained that there may be times during excessive exercise or
extreme hypocaloric diets where an intake closer to 150 grams per day may
temporarily be warranted.
There is no magic to the strict time period of 24 hours. We live our lives in 24
hour chunks out of convenience with the sun’s schedule, but we tend to
assume our nutritional and metabolic needs work this way as well, but this
isn’t the case. There is no reason to stress over the amount of protein you have
eaten over a 24 hour period, some days you’ll be a bit higher, some days you’ll
be a bit lower, it’s the average over weeks and months that matters not hours
and days.
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Finally, since the average protein intake in North America is roughly 90 grams
per day the vast majority of us are already eating enough protein to support
muscle growth. Therefore, we don’t need to obsess over our protein intake the
way fitness magazines and nutrition experts suggest we should.
However, there has been research published that suggests that the current RDA
for protein (0.36 grams per pound bodyweight) may be inadequate for the
maintenance of skeletal muscle in older adults [Campbell, WW 1994], and this
book does agree with the idea that intakes higher than the RDA seem to be
involved in a better (or at least faster) response to muscle building. The range of
70-120 grams of protein is typically above 0.5 grams protein per pound of
bodyweight for most individuals, and would be classified as ‘high protein’ in the
scientific world.
Based on all of this research it seems clear to me that there is a very good
chance that you don’t need to change anything in your diet and can enjoy the
foods you like knowing that you are not hindering your muscle growth.
You don’t need to worry about eating a certain proportion of your diet as
protein, or use special protein sources every couple of hours. In fact, I would
even argue that you do not have to think of foods as protein containing and
non-protein containing foods. Eggs contain an average of 6 grams of protein
and are largely considered to be a protein food. A piece of bread contains
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roughly 5 grams of protein and is NOT considered a protein food. This type of
obsessive compulsive eating and extreme focus on the individual nutrients
contained within foods is simply not required in order to increase your muscle
mass. Especially since more often then not you would consume both the egg
and the bread in a typical meal.
I do not see a reason why protein needs to be consumed every couple of hours,
or evenly spread throughout the day. In fact, I do not see a reason why a large
proportion of the total daily intake could not be consumed in only one or two
meals spread 8 to 12 hours apart. As long as you are resistance training you
will be creating what I call the ‘anabolic advantage’ - this occurs when you use
weight training to sensitize your muscles to the anabolic affects of eating
protein.
Finally, remember that muscle grows very, very slowly. The growth that you
may see after 3 months of a resistance training program is the cumulative
result of close to a hundred workouts and as many as a thousand meals. So it
is the overall consistency of your workouts and your meals that will determine
your muscle growth.
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Eat Stop Eat, Protein Intake and Building Muscle
173
Eat Stop Eat, Protein Intake and Building Muscle
The reason why I wrote this book is twofold. First, I really wanted to
know if I could increase my muscle mass by taking protein after my workouts
and secondly, the necessity of post-workout nutrition was the most asked
question by people who have read my book “Eat Stop Eat”.
It may strike you as odd that the number one question I get about a fat loss
program is about muscle building, but it does make sense. After all, the goal of
losing weight is not to lose just any weight rather it is to lose weight as body fat
exclusively. Therefore following a nutrition strategy like Eat Stop Eat along with
a weight training program for muscle mass naturally leads to the question of
protein and building or maintaining muscle mass.
Eat Stop Eat is a nutrition program that promotes the use of flexible periods of
intermittent fasting combined with resistance training. My philosophy is that
your nutrition habits will be the driving force behind your ability to lose body
fat, and your exercise habits will be the driving force behind your ability to gain
and maintain muscle mass.
Since the current belief is that post-workout protein is vital to the muscle
building process, many people are concerned about lifting weights while in the
fasted state for fear of losing muscle. The fear of muscle loss is especially
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important because losing large amounts of muscle has been associated with a
decreased metabolic rate, especially in older populations.
So ironically the concern about the ability of dietary protein to build muscle is
equally fueled by the desire to build muscle, as it is a desire to burn body fat
without losing muscle.
From the findings in this book I feel confident saying that you can follow Eat
Stop Eat, fast once or twice a week, lift weights and effectively build muscle
mass while still losing body fat.
With the Eat Stop Eat program you never go a day without eating, so you will be
able to eat enough protein to support muscle growth. It’s also important to note
that Eat Stop Eat is the combination of fasting and weight training, but you do
not have to weight train while fasting if you don’t want to, so you can still have
post-workout protein while following Eat Stop Eat if you so choose. On some
days you may eat slightly less protein than other days, but when you average it
all out you’ll easily be able to maintain an adequate protein intake over the
course of a week. You can also work out during your fast if you choose and still
stimulate your muscles to grow, especially since the anabolic effect of a single
workout lasts for at least 24 hours.
175
If on the days when you are eating normally you feel you need to consume extra
protein after your workouts, by all means go ahead. I definitely don’t think it is
going to hurt you in anyway (besides maybe hurting your wallet a bit).
If you are not gaining the amount of muscle mass that you would like to and
you are eating between 70-120 grams of protein per day, then more than likely
there is no need to increase the amount of protein you are eating. In fact, I’d
guess that the problem lies within your workout program, not your protein
intake.
The bottom line is your workouts are what cause you to build muscle. Daily
protein intake does play a part, as does adequate rest and recovery. Most
importantly, missing a post-workout meal once in a while because you are
fasting will not prevent you from gaining muscle.
And we can add that there is even research to suggest that the more
experienced you are at lifting weights the less likely you are to need extra
protein, as you are teaching your body to become more and more efficient at
building muscle.
So the final answer to “how much protein do I need to eat to build muscle” is
the very answer that was first recommended in the late 1800s:
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Eat between 70-120 grams of protein per day in one or multiple meals. Eat
slightly more (up to 150 grams) if you are partaking in higher than average
exercise or a long-term low calorie diet. However, keep in mind that these two
things (excessive vigorous exercise and long-term low calorie diets) are
detrimental to the muscle building process, and simply upping your protein
intake will not completely cancel out these negative affects. My guess is that
stopping the excessive exercise or long-term low calorie diet would be more
anabolic then simply upping your protein intake.
If you need to use a protein supplement to reach these numbers it is fine. If you
can reach these numbers while eating food then there is no need to supplement
with additional protein in the form of shakes, bars or powders. With that said I
have found it rather difficult to eat more than 100 grams of protein per day
without using a supplement.
I hope that this book has helped you understand protein and the muscle
building process. I also hope that you’ve learned not to stress about your
protein intake and that you probably already eat enough protein to build all the
muscle you’ll ever want. Now get to the gym enjoy your workout and enjoy your
food.
177
Frequently Asked Questions
178
Frequently asked Protein Questions
Q: I saw in a bodybuilding magazine that my body can’t absorb more
than 30 grams of protein at time, is this true?
A: No. You’re body does not have a defined upper limit to the amount of protein
it can absorb at a given meal. Your body absorbs and uses all of the protein you
ingest at each meal. The protein you eat is first used to replenish amino acid
pools that are used for a number of cellular processes and are quite literally the
building blocks of all your body’s cells. Any excess protein above this gets
converted into glycogen and stored in your liver or muscle cells.
Q: Do incomplete proteins count in my total protein amount for the day?
A: Yes incomplete protein sources also count in your daily protein amount
because they are still adding to the total amount of protein and amino acid your
body is absorbing. Also most people will be ingesting an incomplete protein with
some other protein source therefore each meal is still delivering all the essential
amino acids.
For example corn is missing the amino acid Leucine, whereas rice is missing
the amino acid Isoleucine. If you eat both of these foods together (it doesn’t
necessarily have to be in the same meal) the meal would provide a source of
complete protein even though each individual food source was incomplete.
179
Q: Does it matter where I get my protein from?
A: Not really. As long as you are eating mixed meals you will almost always be
getting all the amino acids in every meal. In fact, it’s probably best to get your
protein from a wide variety of sources. The amino acid profiles are slightly
different depending if you are eating fish, pork, beef, chicken etc. So while
people have often stated that eggs or some other item (quinoa these days) is the
‘world’s most perfect protein’, in reality a mixture of protein sources is probably
best.
Q: Are some food sources of protein better than others?
A: There are two things to consider when looking at the protein in any food
source.
1) Is the protein complete? A complete protein supplies all of the amino acids
that your body needs for growth and survival. An incomplete protein is missing
at least one of the amino acids your body requires and therefore you would
need to mix an incomplete protein with another source that provides the rest of
the amino acids for proper growth and survival.
2) How much protein does the food have per gram of total foodstuff? For
example 100 grams of chicken breast has much more protein compared to 100
grams of pasta. Both food sources have complete protein however one has
much more protein per gram.
180
Q: I’m a vegetarian, does this mean I need to eat tofu or take protein
powders?
No. You might not realize it but there is lots of protein in foods like multigrain
bread, pasta, grains, nuts, legumes and beans. Be sure to make mixed meals
that include a variety of vegetarian foods, this will ensure that each meal
provides the full spectrum of amino acids. It takes some effort, but it is
possible.
Q: Most bodybuilding magazines say that glutamine is ‘conditionally
essential’ is this true?
A: Glutamine is not one of the essential amino acids. No matter what the
supplement companies tell you, glutamine is not essential, or ‘conditionally
essential’ to bodybuilders. It’s only essential to supplement companies because
it is cheap, tasteless, and mixes easily with water. It makes great ‘filler’ in a
product, and because it is so cheap, you can make a huge profit with it.
Q: Do you destroy the protein in eggs or meat by cooking them?
A: No. Cooking meat, eggs or any protein source does not destroy the protein, it
simply changes the way it is shaped at a molecular level. This change in the
molecular shape of the protein is what causes it to have a different appearance
such as cooked eggs becoming white instead of semi translucent when they are
181
raw. The actual amino acid content of the protein remains the same after
cooking. We typically cook protein sources because it makes them tastes better
and it kills bacteria that grows on raw foods.
Q: Do protein powders really contain as much protein as they say they
do?
A: I would say most quality brands have the real amount of protein that is
stated on the label. However it is possible to make a product appear as though
it has a higher protein content than is actually does. The standard protein test
measures nitrogen content because protein is the only macronutrient that
contains nitrogen, fat and carbohydrates do not.
There are a few inexpensive ingredients that can be added to a protein powder
that also contain nitrogen which will make it appear as though there is more
protein in the product. This is not a very common practice, however it is
possible.
For the most part I would say you get what you pay for with protein. Stick with
a reputable brand and don’t always go for the cheapest protein on the shelf. If
the product gives you gas or bloating or other stomach upset it is probably a
low quality product and you should try a different brand.
182
Q: What about fast and slow digesting proteins?
A: Each protein source will have a characteristic rate of absorption. Protein
powders based with whey will absorb somewhat quicker than casein based
proteins. The rate each protein absorbs doesn’t have any measureable effect on
muscle building or fat burning.
Protein manufacturers use the fast and slow absorbing protein story as a
marketing angle, but I don’t think you will never notice a difference between the
two.
Q: I heard that your body can’t turn protein into fat is this true?
It doesn’t really matter whether or not your body can turn protein INTO fat.
What matters is that no matter what you eat (protein, carbs or fat) if you over
eat, you body will GAIN body fat.
Q: What about all those popular diets that advocate a super high protein
diet?
Believe it or not, even some of the most popular high protein diets DO NOT
advocate super high protein intakes. In fact, two of the most popular diets
“Protein Power” by Dr. Michael Eades and “The Paleo Diet” by Loren Cordain
both recommend protein amounts that are in-line with my suggested intake.
183
In “The Paleo Diet for Athletes” It is recommended that a 200 pound person who
trains with intense exercise for 5 or less hours per week should eat roughly120
pounds of protein.
In “Protein Power” Dr. Eades recommends that we should consume 0.6 grams
of protein per pounds of lean body mass. Even someone who is VERY ACTIVE
(an hour or more of VIGOROUS activity five or more times per week) is
recommended to consume 0.7 grams of protein per pound lean body mass.
To put this into perspective, a 175 pound man with less than 15% bodyfat who
trains with vigorous exercise for more than an hour 6 days per week, still falls
into the range of 70-120 grams of protein.
It is only the bodybuilding subculture that recommends super high protein
diets. Even diets named “Protein Power” still don’t advocate diets that contain
200-300 grams of protein per day as the hardcore bodybuilding culture does.
184
Q: I read that a leading researcher said that high protein was the key to
building muscle, why do you say otherwise?
Here’s the thing most people do not realize – there are dozens of scientists who
study protein and muscle building for a living and they DO NOT agree with
each other. At all. In fact, I’ve been out to dinner with a number of these
doctors and I can tell you that you would NEVER want to have them all in the
same room…it would be a massacre.
So yes, there are some researchers who do condone high protein diets. There
are also some who condone low protein diets. And in the middle are the vast
majority of the scientific experts who condone slightly higher protein diets for
the purpose of muscle growth.
Q: But what about insulin? I thought insulin was needed for muscle
building? So shouldn’t I eat carbs with my protein?
Insulin is a hormone found in the human body that is vital in the metabolism of
carbohydrate, fat and protein. Insulin is considered a storage hormone. It’s main
effect is to cause cells in liver, muscle and fat tissue to take up blood glucose, to stop
the use of fat as an energy source and promote the storage of an energy surplus in
the form of body fat.
185
Most people have heard and accept that glucose (sugar) can increase insulin
secretion, what they don’t normally hear about is that eating protein can also
increase insulin secretion.
In both young and old people, research has shown that 35 grams of casein (a protein
typically found in milk) is enough to spike insulin after an overnight fast.
35 grams of casein provides about 2.5 grams of Leucine and about 7 grams of
branched chain amino acids. So this research is consistent with previous work
showing that even small doses of branched chain amino acids can spike insulin.
This insulin spike from protein occurs very quickly after protein intake, typically
reaching its peak levels at about 15 minutes after ingestion.
If we consider "fasting" insulin to be between 30 and 60 pmol/L, then 35 grams of
casein is able to raise insulin out of the "fasting" range and into what is considered
the "fed state" range (anywhere around 180 pmol/L).
So a small amount of insulin is needed, but this is the amount that is naturally
released into your blood whenever you eat protein.
186
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187
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