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TRAINING MANUAL

Part I

Fundamentals of Nutrition

B.V.Srinivas

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NUTRITION

Foods that we eat provide the energy the body requires to function. The main form of energy used by the body is carbohydrate. Carbohydrates are broken down into individual units of glucose, fructose or galactose. Glucose is the body's favorite form of energy. If sufficient carbohydrates are not available, our body can make glucose from proteins or fats stored in the body. If too much of carbohydrate is consumed, the body is able to store the excess as fat. Therefore, Nutrition can be defined as a process of consuming food and supplements and using it for energy, growth and repair.

Nutrition is the sum total of the processes involved in the taking in and the utilization of food substances by which growth, repair and maintenance of the body are accomplished. It involves ingestion, digestion, absorption and assimilation. Nutrients are stored by the body in various forms and drawn upon when the food intake is not sufficient.

Why is nutrition important?

Our body needs the right food and regular exercise, lifestyle and mental attitude to achieve its true health potential. Nothing is more important than healthy eating!

Maintaining a balanced diet by healthy eating can: Give vitality and energy for life Help stay at a weight that's right Boost your immune system Improve sports performance Delay the effects of aging Help beat tiredness and fatigue Protect teeth and keep gums healthy Enhance ability to concentrate and possible alter mood Ward off serious illnesses like heart disease, certain cancers, maturity onset

diabetes, and gallbladder disease

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Nutrients

A nutrient is an active chemical component of food that an organism needs to perform

one or more of the following functions:

Supply energy

Regulate body processes

Promote growth and repair body tissues.

Types of Nutrients

Organic nutrients include carbohydrates, fats, proteins (or their building blocks, amino

acids), and vitamins.

Inorganic nutrients include dietary minerals & water. A nutrient is said to be

"essential" if it must be obtained from an external source, either because the organism

cannot synthesize it or produces insufficient quantities. Nutrients needed in very small

amounts are micronutrients and those that are needed in larger quantities are called

macronutrients. The effects of nutrients are dose-dependent and shortages are

called deficiencies.

Macronutrients provide energy, which is measured either in kilocalories (kcal) or Joules. 1 kcal = 4185.8 joules.

Food that we eat holds a collection of essential nutrients that are used by our body so that our body can perform these 3 functions of build, repair and regulate. These essential nutrients are:

Macronutrientso Carbohydrateso Fatso Proteins

Micronutrientso Vitaminso Mineralso Water

Nutrition and Chronic Disease

Nutrition during therapy for a chronic disease/illness can significantly affect outcomes. Good nutrition helps in tolerating and completing the course of treatment and fight disease process. It also helps in avoiding excess weight loss and maintain muscle mass and strength, preserving the body’s ability to continue with normal activities - an important factor for measuring the quality of life.

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Maintaining adequate nutritional status improves immune function and less vulnerable to infections that accompanies malnutrition. Also, good nutritional choices may help limit the risk of its recurrence.

Dietary reference intake

The following are the Dietary Reference Intake recommendations used in various countries.

Recommended Dietary Allowances (RDA) or Reference Daily Intake or Recommended Daily Intake (RDI) the daily dietary intake level of a nutrient considered sufficient by the Food and Nutrition Board of the USA to meet the requirements of 97.5% of healthy individuals in each life-stage and gender group

Dietary Reference Values (DRV) is the recommended nutritional intakes for the UK population. The DRVs can be divided into three types:

o RNI - Reference Nutrient Intake (97.5% of the population's requirement is met)

o EAR - Estimated Average Requirement (50% of the population's requirement is met)

o LRNI - Lower Recommended Nutritional Intake (2.5% of the population's requirement is met)

Percentage daily value (PDV), The Percent Daily Value is a guide to the

nutrients in one serving of food. Eg. If the label lists 15 percent for calcium, it

means that one serving provides 15 percent of the calcium that one needs

each day.

The Percent Daily Value is based on a 2,000-calorie diet for healthy adults. Even if the

diet is higher or lower in calories, one can still use the Percent Daily Value as a guide.

Eg. Percent Daily Value can help determine whether a food is high or low in specific

nutrients:

If a food has 5 percent or less of a nutrient, it's considered to be low in that

nutrient.

If it has 20 percent or more, it's considered to be high in that nutrient.

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The dietary values recommended by FDA for a 2000 calorie diet for both adults and children of 4 years and above for macronutrients are as given below:

Macronutrient Daily Reference Value Calories % Energy

TOTAL FAT 65gm 585 30%

Saturated Fatty Acid 20gm

Cholesterol 300mg

TOTAL CARBOHYDRATE 300gm 1200 60%

Dietary Fiber 25gm

TOTAL PROTEIN 50gm 200 10%

Sodium 2400mg

Potassium 3500mg

Factors affecting the energy requirement of Individuals

The daily dietary calorie requirements of an individual dependa on age, sex, metabolism, activity level, and body size. The following factors can affect the calorie requirements of an individual>

Age: The calorie requirements peak at the age of about 25 and then decline by about 2 percent for every 10 years.

Eg. If for a 25 years old, to maintain weight, the calorie requirement is around 2,200, by the time the person turns 35, the calorie requirement comes down to2,156. Similarly, by the age of 45, the requirement will be 2,113 and at the age of 55 it works out to 2,071 and so on.

The aging body replaces muscle with fat, which burns fewer calories than muscle does. Staying active and doing muscle-strengthening exercises keeps muscle mass in tact.

Gender: An adult man has less body fat and about 10 to 20 percent more muscle than a woman of the same size and age. Because muscle burns more calories than fat does, a man’s calorie needs are generally about 5 to 10 percent higher than a woman’s. The exception for women is during pregnancy and breast-feeding.

Metabolism: A living body needs a minimum number of calories to maintain vital functions, such as breathing and keeping its heart beating. This minimum number is called Basal Metabolic Rate (BMR).

Genetic blueprint: The metabolic rate that one inherits from their family in part determines the number of calories that a body requires to function. Inherited metabolic diseases, specifically those that affect thyroid, can cause one to burn

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calories very quickly or very slowly. A malfunctioning thyroid gland can sabotage your best weight-loss efforts.

Body shape and size: The shape and size of the body determines the calories required because muscles burns more calories than body fat does. So if one solid and has a greater proportion of muscle to fat, then the metabolism is higher. Likewise, if one has more body fat and less muscle, then themetabolism is lower, and there is a greater tendency to store fat than someone who is tall and thin.

Activity levels: When one is active, more calories are burnt. If the amount of calories burnt (or expend) is more than the calories consumed, it results inweight loss.

Pregnancy: During the last trimester of pregnancy, energy requirement increases by about 200 kcals/day. Although energy is required in the early stages of pregnancy for the development of the foetus, the body will be able to compensate for the increased requirements by becoming less active and utilising the energy more efficiently.

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Food Pyramid

The food guide pyramid has been adopted by the US Department of Agriculture and the Department of Health and Human Services to encourage people to eat healthily. Six major groups of food are arranged in a pyramid shape to indicate the number of recommended daily servings of each group: the food group with the highest number of recommended daily servings (bread, cereal, and pasta group) form the base of the pyramid; the group with the lowest recommended number of servings (fats, oils, and sweets) form the apex of the pyramid. The guidelines are for the average person. All active people should have at least the lowest number of servings recommended for each food group. Very active people, especially serious athletes and those in physically demanding jobs, may need more than the larger number of recommended servings.

In the UK an alternative diagrammatic guide to the food guide pyramid has been introduced. It is called the ‘plate model’. This diagram takes the form of a plate divided into five sections representing the main food groups: bread, other cereals, and potatoes; milk and dairy foods; fatty and sugary foods; meat, fish, and alternatives; and fruit and vegetables.

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Metabolism

It is a set of all chemical reactions that occur in living organisms, including digestion and transport of substances into and between different cells.

Metabolism is usually divided into two categories. Catabolism breaks down organic matter, for example to harvest energy in cellular respiration. Anabolism uses energy to construct components of cells such as proteins and nucleic acids.

The chemical reactions of metabolism are organized into metabolic pathways, in which one chemical is transformed through a series of steps into another chemical, by a sequence of enzymes. Enzymes are crucial to metabolism because they allow organisms to drive desirable reactions that require energy and will not occur by themselves, by coupling them to spontaneous reactions that release energy. As enzymes act as catalysts they allow these reactions to proceed quickly and efficiently. Enzymes also allow the regulation of metabolic pathways in response to changes in the cell's environment or signals from other cells.

Basal metabolic rate (BMR)

It is the amount of energy expended daily by humans and other animals at rest or sleep

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MACRONUTRIENTS

1. Carbohydrates

Carbohydrates are organic compounds that consist only carbon, hydrogen, and oxygen, with a hydrogen:oxygen atom ratio of 2:1.

Carbohydrates are the structural materials of plants and are produced by one of the most complex processes called photosynthesis. Because they are an integral part of plant life, it is no wonder that carbohydrates are in most fruits and vegetables. And though they are not a dietary requirement in the way that vitamins or essential amino acids are, it is difficult to eat without ingesting some carbohydrates, which are excellent sources of quick-burning energy. Not all carbohydrates are of equal nutritional value, however: in general, the ones created by nature are good for the body, whereas those produced by human intervention—some forms of pasta and most varieties of bread, white rice, crackers, cookies, and so forth—are much less beneficial.

Carbohydrates are divided into groups according to the number of individual simple sugar units. Monosaccharides contain a single unit, Disaccharides contain two sugar units; and Polysaccharides contain many sugar units as in polymers - most contain glucose as the monosaccharide unit.

CarbohydratesMonosaccharides Disaccharides Polysaccharides

Glucose Sucrose Starch

Galactose Maltose GlycogenFructose Lactose Cellulose

RiboseGlyceraldehyde

Most carbohydrates that occur in nature are in the form of monosaccharides (such as glucose), disaccharides (such as table sugar, or sucrose, and milk sugar, or lactose), and polysaccharides (such as starch and glycogen)

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Monosaccharides

These are the simplest carbohydrates in that they cannot be hydrolyzed to smaller carbohydrates. Monosaccharides are important fuel molecules as well as building blocks for nucleic acids..

Disaccharides

These are two monosaccharides joined together by a covalent bond and these are the simplest polysaccharides. Sucrose is the most abundant disaccharide and the main form in which carbohydrates are transported in plants. It is composed of one d-glucose molecule and one d-fructose molecule. Lactose, a disaccharide is composed of one d-galactose molecule and one d-glucose molecule and occurs naturally in mammalian milk.

Disaccharides can be further classified into two types - reducing and non-reducing disaccahrides. A reducing disaccharide is one in which the functional group allows the sugar to act as a reducing agent.

Oligosaccharides and polysaccharides (Complex carbohydrates)

These are composed of longer chains of monosaccharide units bound together by glycosidic bonds. The distinction between the two is based upon the number of monosaccharide units present in the chain. Oligosaccharides typically contain between three and ten monosaccharide units, and polysaccharides contain greater than ten monosaccharide units.

The function of Polysaccharides in a living organism is usually either related to structure or storage. In plants, polysaccharides are stored as starch (a polymer of glucose) while in animals, it is stored as glycogen, sometimes called 'animal starch'. Glycogen's properties allow it to be metabolized more quickly, which suits the active lives of moving animals.

Cellulose and chitin are examples of structural polysaccharides. Cellulose is found in the cell walls of plants and other organisms and is claimed to be the most abundant organic molecule on earth. It has many uses including the manufacture of paper, textiles and rayon. Chitin has a similar structure, but is much stronger compared to cellulose. It is found in arthropod exoskeletons and in the cell walls of some fungi. It also has multiple uses, including the manufacture of surgical threads.

Role and benefits of Carbohydrates

Carbohydrates are the main source of fuel for all of the body's cells and the only source of energy for the brain and red blood cells. Except for fiber, which cannot be digested, both simple and complex carbohydrates are converted into glucose, which is then either used directly to provide energy for the body, or stored in the liver for future use. When a person consumes more calories than required, a portion of the carbohydrates consumed may also be stored in the body as fat. Carbohydrate

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restriction improves glycaemic control, the primary target of nutritional therapy and reduces insulin fluctuations.

Fructose, also known as fruit sugar is mainly found in fruits and honey. It is the sweetest of all the simple sugars. The absorption of fructose into the blood stream is much slower than that of glucose. This leads to less problems associated with roller coaster blood glucose levels that leave us feeling tired.

Refined flour and sugar are perhaps the worst enemies that cause weight gain. Excessive intake of food products rich in these two ingredients can cause blood glucose levels to increase, triggering additional production of insulin, and causing the body to convert carbohydrates to fat. Eating low carbohydrate foods would ensure supply of adequate amount of blood glucose needed by the body. Further, the bodyburns its fat stores instead of carbohydrates that helps in reducing weight.

Table sugar another form of refined sugar comes from two primary sources: sugar cane and sugar beets. Sucrose in its completely refined stage is called table sugar which is devoid of all nutritional and other elements.

Molasses is a by-product of sugar refining—a sweet thickened liquid obtained from the second extraction; and black-strap molasses in the liquid left after the third extraction. Light and dark brown sugar are simple refined table sugar to which is added 12-13% molasses.

Maltodextrin

Maltodextrin is a polysaccharide with a low molecular weight. Maltodextrin is produced by hydrolysing starch. Maltodextrin can be digested easily, and is available as a white powder..

Maltodextrin has wide range of applications as a food additive for its low content of calorie. Generally, 1 gm of maltodextrin contains only 4 calories. It is usually sweet or without any flavor. The characteristic of maltodextrin varies according to the source of starch, i.e., whether it is produced from rice, wheat, corn or potato.

Maltodextrin is ideal as a sugar substitute for people trying to control their weight. It can also be used by people suffering from diabetes, as a sweetener in tea, coffee, etc.

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Fiber

Fiber or "roughage" as it is also known, is essentially a carbohydrate and is found solely in plants. It is found in the walls of the plant's cells and is the only part of the plant that cannot be digested by the human body. The main function of fibre is to keep the digestive system healthy and functioning properly. Fibre aids and speeds up the excretion of waste and toxins from the body, preventing them from sitting in the intestine or bowel for too long, which could cause a build-up and lead to several diseases.

A variety of definitions of fiber exist. In an attempt to develop one definition of fiber that everyone can use, the Food and Nutrition Board assembled a panel that came up with the following definitions:

Dietary fiber: Consists of nondigestible carbohydrates and lignin that are intrinsic and intact in plants. This includes plant non-starch polysaccharides (for example, cellulose, pectin, gums, hemicellulose, and fibers contained in oat and wheat bran), oligosaccharides, lignin, and some resistant starch.

Functional fiber: Consists of isolated, non-digestible carbohydrates that have beneficial physiological effects in humans. This includes non-digestible plant (for example, resistant starch, pectin, and gums), chitin, chitosan, or commercially produced (for example, resistant starch, polydextrose, inulin, and indigestible dextrins) carbohydrates.

Total fiber is the sum of dietary fiber and functional fiber. It's not important to differentiate between which forms of each of these fibers one is getting in the diet. It is the total fiber that matters and fiber is an essential part of everyone's diet. While fiber does fall under the category of carbohydrates, in comparison, it does not provide the same number of calories, nor is it processed the way that other sources of carbohydrates are. This difference can be seen among the two categories that fiber is divided into: soluble and insoluble.

Soluble fiber dissolves in water to form a gel-like substance. Sources of soluble fiber are oats, legumes (beans, peas, and soybeans), apples, bananas, berries, barely, some vegetables, and psylluim. Soluble fibre absorbs water in the intestine, which softens the stool and helps the waste material move through the body more quickly.

It is thought that soluble fibre may help to reduce the level of cholesterol in the blood. This is due to the fact that soluble fibre binds the cholesterol from food or from bile acids, which are made up of cholesterol, preventing it from being absorbed into the bloodstream. This is then eliminated as waste, as the fibre cannot be digested.

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Soluble fibre also slows down digestion and the sudden release of energy, especially from carbohydrates into the bloodstream. This means that blood sugar levels are more stable, which is good for people with diabetes, and energy or glucose is released slowly and steadily, preventing sudden feelings of tiredness, lack of energy or hunger pangs.

Sources of soluble fibre

Soluble fibre-rich foods include fruits, vegetables, lentils, peas, beans, oats, barley, oatmeal, potatoes, dried fruit, soya milk and soya products.

Foods that are low in fibre

Eating a diet that does not contain enough fibre can lead to bowel irregularities and stomach discomforts. Foods that do not contain any or contain very little fibre include refined cereals and white bread, meat and animal products, dairy produce and fast foods.

Dietary fiber is also classified into 2 types: insoluble and soluble. Both types of fiber are composed of dense indigestible polysaccharide carbohydrates whose structure cannot be converted into glucose by human digestive enzymes. Paradoxically, the indigestibility of fiber makes it a very healthy addition to our daily diet. Insoluble fiber (eg. cellulose, a few hemicelluloses and lignin in plants and whole grains) benefits digestion by stimulating peristalsis - the muscle movements that propel food along the colon. Being bulky, the fiber allows the colonic muscles to get a better "grip". Point is, if food moves faster through the large intestine, the risk of digestive disorders (eg. constipation, diverticulitis, even colon cancer) is reduced.

Insoluble fiber Fiber passes through the body virtually unchanged along with other digested food until it arrives at the large intestine. What happens next depends on which type of fibre is present. increases the movement of material through your digestive tract and increases your stool bulk. Sources of insoluble fiber are whole wheat foods, bran, nuts, seeds, and the skin of some fruits and vegetables.

In the case of insoluble fibre, it promotes the growth of a certain friendly bacteria that ferments and makes the waste material soft and bulky, which in turn helps it to pass through the intestines quicker to the bowel and out of the body.

Insoluble fibre prevents constipation, which consists of small, hard and dry faeces that are hard to pass, by adding bulk and liquid to aid movement, and promote regular bowel movements. A larger and softer stool is able to pass through the intestines and bowel more easily and fluidly and is easier to evacuate.

As waste material passes through the body quickly and does not stay in the intestines or bowel for very long, toxins are not able to build up and accumulate. This is important in the prevention of distressing diseases such as bowel cancer or other cancers, constipation, irritable bowel syndrome, haemorrhoids and diverticulitis.

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Sources of insoluble fibre

Insoluble fibre can be found in foods such as bran, wholemeal flour and breads, brown rice, whole grain cereals, vegetables, edible peels of fruit, nuts and seeds.

The following foods are good sources of fiber:

o Whole grains (bran has the highest fiber content); this includes breads and cereals, whole-grain pastas, and brown rice

o Nuts and seedso Legumes (such as dried peas, beans, lentils)o Fruitso Vegetableso A dietary supplement of fiber products such as Citrucel or Metamucil, which are

mixed with water and provide about 4 to 6 grams of fiber in each 8-ounce glass

When foods are processed, fiber is often removed. Foods made from white flour (bleached or unbleached) are poor sources of fiber, including white breads, pizza crusts, and regular pasta. In general, foods that are less processed are higher in fiber.

Fiber Intake for Women/Men

AgeFiber grams/day for

WomenFiber grams/day for

Men

19 to 30 years 25 g/d 38 g/d

31 to 50 years 25 g/d 38 g/d

51 to 70 years 21 g/d 30 g/d

70+ years 21 g/d 30 g/d

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Resistant Starch

A resistant starch is a starch that resists the enzymatic action and doesn’t break down into sugar molecules. For example, raw cornstarch. Because they don’t break down into sugar, resistant starches aren’t absorbed into the bloodstream. Instead, they pass largely undigested into the large intestine.

What are the Benefits of Resistant Starches?

Improve bowel function. Resistant starches act a lot like fiber. As with fiber, adding resistant starch to the diet can improve regularity and bowel function. Some people find that when they up their fiber intake, especially if they do it suddenly, they have bloating, gas pains, and other effects usually lumped together under the heading of “GI distress.” One nice thing about resistant starch is that it doesn’t have this unwelcome side effect.

Appetite Control. Another fiber-like benefit of resistant starch is that it appears to help with appetite control, helping one feel fuller, longer, even when one is eating fewer calories

Regulate blood sugar. When resistant starches are included in a meal, it slows down the absorption of sugars from other foods. That means that there js a more gradual rise and fall in blood sugar levels after eating. That’s particularly helpful for diabetics, who need to keep their blood sugar levels steady.

Reduce calories. Foods containing a lot of resistant starches are somewhat lower in calories than other carbohydrates because at least some of the food energy stays locked up in the resistant starch and doesn’t get digested and absorbed.

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Calories

Calorie is a measurement of energy available in the food and consumed by the body. It is the unit of heat that is required to raise the temperature of one kilogram of waterby 1 degree Celsius. Our body uses energy for many functions such as breathing, pumping blood, resting, sitting, working, and exercising. Consumption of more calories than usage results in deposition as fat leads to weight gain. Burning more calories than consumption leads to weight loss.

Recommended daily calorie intake varies from person to person. The average calorie requirement to maintain a desirable weight in men requires around 2,700 calories/day and in women about 2,000 calories/ day. These figures apply to adults with low activity levels. Factors that effect ones personal daily calorie requirements include age, height and weight, level of daily activity and body composition.

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2. Proteins

Proteins are the main building blocks and functional molecules of the cell, Every cell and tissue in the body contains protein including the muscles, bones, hair, nails and skin, accounting to around 20 percent of total body weight. Proteins are necessary for building the structural components of the human body, such as muscles and organs Different proteins work as enzymes, hormones, neurotransmitters, antibodies and specialised proteins such as haemoglobin and others, constantly repair body tissues to keep it healthy. Proteins also provide energy when the body is starved of carbohydrates. They provide 4kcals/gm of protein.

Proteins are large molecules made up of several building blocks called amino acids.Amino acids are linked together to form peptides, which are small chains of amino acids. The peptides are then linked together to form larger molecules called proteins. There are 20 amino acids. that can be arranged in millions of different ways. Depending on the sequence in which they are combined, the resulting protein carries out specific functions in the body.

The body gets amino acids from protein-containing foods. Digestive enzymes break proteins into amino acids which are then absorbed by the body to rebuild them into new sequences that are needed for body’s growth, maintenance and control of body processes.

Based on the functions, Proteins are classified as below:

Enzymatic

Enzymatic proteins are enzymes that speed up chemical reactions in the body. These enzymes increase metabolism and converting glycogen into glucose. Glycogen stores energy in the liver and muscles and glucose is the simple sugar that gives the energy.

Structural

Structural proteins consist of keratin, elastin and collagen that exist in the outer coverings of humans and animals and these make up skin, fur, scales, feathers, fingernails, hair, teeth and hooves. Other structural proteins are myosin and actin that exist in smooth muscle tissue such as in the lungs, uterus, intestinal tract and blood vessels, and maintain the structural integrity of the cell.

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Storage

The main function of storage proteins is to store metal ions such as iron in the body. Our body requires iron to transport hemoglobin for cell metabolism. The storage protein ferritin also helps regulate any bad effects of too much iron. The amino acids in storage protein aid in embryonic development. Casein and ovalbumin are two storage proteins found in egg whites and breast milk.

Transport

The transport protein calbindin carries calcium along the intestinal wall for absorption. Another transport protein is serum albumin that carries lipids in the blood. Hemoglobin is also a transport protein that brings oxygen to the lungs and tissues. Myoglobin takes oxygen from the hemoglobin and holds it until the muscles need oxygen.

Hormonal

Hormonal proteins are hormones found in the endocrine glands. Some of these proteins are peptides, while others are steroids. Each of the hormonal proteins target a specific part of the body, such as insulin that targets the pancreas or the human growth hormone released from the hypothalamus. Examples of steroid hormonal proteins are estrogen and progesterone.

Receptor

Receptor proteins are located at the exterior of the cell plasma membrane and regulate substances and nutrients in and out of the cells, similar to a pump. Hormones, antibodies, nutrients and growth factors attach themselves to the receptor proteins.

Our body has three types of protein receptors that function in different ways. One of these receptors causes enzymes to transform from inactive to active. The second type of receptor stimulates cells to open and allow sodium to pass through the membranes. The third protein receptor stimulates the glands to release epinephrine if the blood sugar is too low and to release insulin if the blood sugar is too high.

Contractile

Contractile proteins, also called motor proteins, control contractions in the heart and muscles. These proteins regulate the speed and strength of the contractions. The two major contractile proteins are myosin and actin, which interact with each other to produce the muscle contractions. If the contractile proteins produce contractions that are too severe, it can lead to heart disease.

Defensive

Defensive proteins are antibodies that help the immune system fight off disease. The antibodies are made in the white blood cells and bind to viruses and bacteria, making them inactive.

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There are thousands of different proteins that carry out a large number of functions in the human body. Even though so many different proteins at work in the body, we don't have to worry about consuming each individual protein from the foods we eat. Our body will make those proteins. All we need to do is to make sure our body has ahealthy supply of all 20 different amino acids. Having enough of these amino acids is easy because our body can make 12 of them from other compounds already in our body. That leaves eight amino acids that we must get from our diet. Those eight amino acids are called "essential amino acids."

There are two types of amino acids-essential and non-essential. The essential amino acids cannot be made in sufficient amounts in the body, and must therefore be supplied in the food. The non-essential amino acids can be made from other amino acids in the diet. Foods containing animal protein, such as meat, milk and eggs, contain ample amounts of all the essential amino acids. Vegetable protein sources have one or more of the essential amino acids missing or have less than the adequate amounts. These foods, however, can be combined in a diet that supplies the required amounts.

Most people need to have 10-15 per cent of their total calorie intake in protein; this is about 0.75 grams of protein per kilogram of body weight per day. Hence, a 70-kilogram man and a 55-kilogram woman need 50 to 60 grams and 40 to 50 grams per day, respectively. Two or three servings of animal protein foods or four servings of mixed vegetable-protein sources, such as whole grain cereals, vegetables, legumes, nuts and seeds can easily provide the needed protein.

The body cannot store amino acids so it is constantly breaking down and remaking proteins. This 'protein turnover' or recycling process must be constantly fuelled by proteins in the diet. There will often be excesses of some amino acids and of total protein. The liver converts these to glucose to be used to provide energy.

The non-essential amino acids are not called "non-essential" because we don't need to get them from our diet but our body can build them from the chemicals already present in our body. They are important and our body requires them to perform several functions.. The non-essential amino acids include:

o Alanineo Arginineo Aspartic acido Cysteine & Cystineo Glutamic Acido Glutamineo Glycineo Ornithineo Prolineo Serineo Taurineo Tyrosine

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Amino acids Arginine, Cysteine, Glycine, Glutamine and Tyrosine are sometimes considered to be "conditionally essential." Most people manufacture them on their own, but in some with certain illnesses or disease states it needs to be supplied through diets.

The nine essential amino acids are called "essential" because our body can't manufacture them and therefore, we have to eat proteins that contain these amino acids. The essential amino acids include:

o Histidineo Isoleucineo Leucineo Lysineo Methionineo Phenylalanineo Threonineo Tryptophano Valine

Amino Acid Function Deficiency seen inAlanine Important source of energy for muscle.

The primary amino acid in sugar metabolism.Boosts immune system by producing antibodiesMajor part of connective tissue

Hypoglycemia, muscle breakdown, fatigueviral infections, elevated insulin and glucagon levels

Arginine Essential for normal immune system activity.Necessary for wound healing.Assists with regeneration of damaged liver.Necessary for production and release of growth hormoneArginine is the most potent amino acid in releasing insulin.Assists in healing through collagen synthesisDecreases size of tumors.Necessary for spermatogenesis.

AIDSImmune deficiency syndromes, including CFS and Gulf War SyndromeCandidiasis

Aspartic Acid&

Arginine

Aspartic Acid is interconvertible with Asparagine, and therefore the two amino acids have many functions in common.Increases stamina.Helps protect the liver by aiding the removal of ammonia.Involved in DNA and RNA metabolism, immune system function by enhancing immunoglobulin production and anti- body formation.

Calcium and magnesium deficiencies. Because of this association, low aspartic acid levels should lead the clinician to test for calcium and/or magnesium deficiencies.

Cysteine&

Cystine

Cysteine and Cystine are interconvertible. Two molecules of Cysteine make Cystine.Antioxidant.Protects from radiation, pollution, ultra-violet light and other causes of increased free radical production.Natural detoxifier.Essential for growth, maintenance, and repair of skin and a key ingredient in hair.

Chemical SensitivityFood Allergy

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Glutamic Acid Precursor to Glutamine and An excitatory neurotransmitter.Helps stop alcohol and sugar cravings.Increases energy.Accelerates wound healing and ulcer healing.Detoxifies ammonia in the brain by forming glutamine, which can cross the blood-brain barrier, which Glutamic Acid cannot do.Plays major role in DNA synthesis.

Excesses in brain tissue can cause cell damage -mechanism by why strokes kill brain cells through release of large amounts of Glutamic Acid.

Glutamine Precursor to the neurotransmitter GABA. Essential for helping to maintain normal and steady blood sugar levels.Involved with muscle strength and endurance.Essential to gastrointestinal function; provides energy to the small intestines. The intestines are the only organ in the body that uses Glutamine as its primary source of energy.Glutamine has the highest blood concentration of all the amino acids.Involved in DNA synthesis.

Chronic Fatigue SyndromeAlcoholismAnxiety and Panic Disorders

Glycine Part of the stucture of hemoglobin.Main inhibitory neurotransmitterPart of cytochrome - enzyme involved in energy production.Inhibits sugar cravings.Involved in glucagon production, which assists in glycogen metabolism.

Chronic Fatigue SyndromeHypoglycemiaAnemiaViral InfectionsCandidiasis

Histidine Found in high concentrations in hemoglobin.Useful in treating anemia due to relationship to hemoglobin.Has been used to treat rheumatoid arthritis.Precursot to histamine.Associated with allergic response and has been used to treat allergy.Assists in maintaining proper blood pH.

Rheumatoid arthritisAnemiaDysbiosis (Imbalance of intestinal bacterial flora)

Isoleucine A branched-Chain Amino Acids (BCAA)Involved with muscle strength, endurance, and muscle stamina.Muscle tissue uses Isoleucine as an energy source.Required in the formation of hemoglobin.

ObesityHyperinsulinemiaPanic DisorderChronic Fatigue Syndrome

Leucine A branched-chain amino Has all of the properties discussed with Isoleucine.Potent stimulator of insulin.Helps in bone healing.Helps promote skin healing.Modulates release of Enkephalins, which are natural pain-reducers.

HyperinsulinemiaDepressionChronic Fatigue Syndrome Acute hungerKwashiorkor (starvation)Vitamin B-12 deficiency in pernicious anemia

Lysine Inhibits viral growth L-Carnitine is formed from Lysine and Vitamin C.Helps form collagen, the connective tissue present in bones, ligaments, tendons, and joints.Assists in the absorption of calcium.Essential for children, as it is critical for bone formation.Involved in hormone production.Lowers serum triglyceride levels.

HerpesEpstein-Barr VirusChronic Fatigue SyndromeAIDSAnemiaHair lossWeight lossIrritability

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Methionine Assists in breakdown of fats.Helps reduce blood cholesterol levels.Antioxidant.Assists in the removal of toxic wastes from the liver..Helps prevent disorder of hair, skin, and nails Required for synthesis of RNA and DNA.Natural chelating agent for heavy metals, such as lead and mercury.

Chemical ExposureMultiple Chemical Sensitivity (MCS)Vegan Vegetarians

Phenylalanine Enhances mood, clarity of thought, concentration, and memory.Suppresses appetite.Major part of collagen formation.While the L-form of all of the other amino acids is the one that is beneficial to people, theD and DL forms of Phenylalanine have been useful in treating pain.Powerful anti-depressant.Used in the treatment of Parkinson's Disease.

DepressionObesityCancerAIDSParkinson's Disease

Proline Critical component of cartilageInvolved in keeping heart muscle strong.Works in conjunction with Vitamin C in keeping skin and joints healthy.

Serine Critical in maintaining blood sugar levels.Boosts immune system by assisting production of antibodies and immunoglobulins.Required for growth and maintenance of muscle.

Total body gamma and neutron irradiationHypoglycemiaCandidiasis

Threonine Required for formation of collagen.Helps prevent fatty deposits in the liver.Aids in production of antibodies.Needed by the GI (gastrointensinal) tract for normal functioning.Threonine increases thymus weight.Threonine is helpful in treating the depression.

DepressionAIDSMuscle SpasticityALS (Amyotrophic Lateral Sclerosis)VegetarianismEpilepsy

Tryptophan Effective sleep aid and reduces anxiety.Effective in some forms of depression, migraine headaches.Stimulates growth hormone.Effective in lowering cholesterol levels.Lowers risk of arterial spasms.

DepressionInsomniaChronic Fatigue SyndromeALSFDA ban of Tryptophan

Tyrosine Effective anti-depressant for norepinephrine-deficient depressions.

DepressionChronic Fatigue SyndromeGulf War SyndromeHypothyroidismParkinson's DiseaseDrug addiction and dependency

Valine Improves muscle strength, endurance, and muscle stamina..Used directly by muscle as an energy source.Any acute physical stress (including surgery, sepsis, fever, trauma, starvation) requires higher amounts of Valine, Leucine and Isoleucine Needed for the absorption of, all of the other amino acids by the GI tract.

KwashiorkorHungerObesityNeurological deficitElevated insulin levels

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3. Fats

Fats are organic compounds and belong to a group of substances called lipids. Fats made up of 3 molecules of fatty acids and 1 molecule of glycerol and are present in both solid and liquid forms. Fats are essential for normal health, growth and development. Fat is a good source of energy that is stored in the body and provides 9 kcal/gm.

Fats are derived from both animals and plants. Fats obtained from plants are called Vegetable fat e.g. Margarine and Vegetable oil. Fats obtained from animal sources are called Animal fat e.g. Butter, Cream and Lard.

Fats are often considered unhealthy but they are essential to our bodies. According to the Dietary Reference Intakes published by the USDA 20% - 35% of calories should come from fat Some of the key benefits of fats are:

Help body absorb, digest and transport vitamins like A,D,E & K Maintain body temperature Fat provides the structural components not only of cell membranes in the brain,

but also of myelin, the fatty insulating sheath that surrounds each nerve fiber, enabling it to carry messages faster..

Energy: Gram for gram fats is the most efficient source of food energy. Each gram of fat provides nine calories of energy for the body, compared with four calories per gram of carbohydrates and proteins.

Healthier skin: One of the more obvious signs of fatty acid deficiency is dry, flaky skin. In addition to giving skin its rounded appeal, the layer of fat just beneath the skin acts as the body's own insulation to help regulate body temperature.

Healthy cells: Fats are a vital part of the membrane that surrounds each cell of the body. Without a healthy cell membrane, the rest of the cell couldn't function.

Making hormones: Fats are structural components of some of the most important substances in the body, including prostaglandins, hormone-like substances that regulate many of the body's functions. Fats regulate the production of sex hormones, which explains why some teenage girls who are too lean experience delayed pubertal development and amenorrhea.

Protective cushion for our organs: Many of the vital organs, especially the kidneys, heart, and intestines are cushioned by fat that helps protect them from injury and hold them in place.

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Fatty Acids

Fatty acids are acids produced when fats are broken down. They are considered “good fats.” These acids are not highly soluble in water, and they can be used for energy by most types of cells. Fatty acids are found in oils and other fats that make up different foods. They are an important part of a healthy diet, because the body needs them for several purposes. Fatty acids help move oxygen through the bloodstream to all parts of the body. They aid cell membrane development, strength, and function, and they are necessary for strong organs and tissue.

Fatty acids can also help keep skin healthy, help prevent early aging, and may promote weight loss by helping the body process cholesterol. More importantly they help rid the arteries of cholesterol build up. Another purpose of fatty acids is to assist the adrenal and thyroid glands, which may also help regulate weight.

Fatty acids serve as energy for the muscles, heart, and other organs as building blocks for cell membranes and as energy storage for the body. Fatty acids that are not used up as energy are converted into triglycerides. A triglyceride is a molecule formed by attaching three fatty acids onto a glycerol compound that serves as a backbone. Triglycerides are then stored in the body as fat (adipose) tissue.Saturated fatty acids contain single bonds only. Fats containing saturated fatty acids are called saturated fats. Examples of foods high in saturated fats include lard, butter, whole milk, cream, eggs, red meat, chocolate, and solid shortenings. An excess intake of saturated fat can raise blood cholesterol and increase the risk of developing coronary heart disease.

Monounsaturated fatty acids contain one double bond. Examples of foods high in monounsaturated fat include avocados, nuts, and olive, peanut, and canola oils. Scientists believe that increased consumption of monounsaturated fats (for example, eating more nuts) is beneficial in lowering LDL cholesterol (the "bad" cholesterol) and lowering the risk of coronary heart disease, especially if monounsaturated fats are used to substitute for saturated fats and refined sugars.

Polyunsaturated fatty acids contain more than one double bond. Examples of foods high in polyunsaturated fats include vegetable oils, corn, sunflower, and soy.

Essential fatty acids are polyunsaturated fatty acids that the human body needs for metabolic functioning but cannot produce, and therefore has to be acquired from food

Saturated fats. Found in both animal and plant products such as whole milk, meats, coconut and palm oils. They can increase "bad" (LDL) cholesterol which increases the risk of hardening of the arteries or atherosclerosis and therefore, should be a limited part of the diet. These fats contain maximum amount of hydrogen which results in solidification. Saturated fats can stack themselves in a closely packed arrangement, so they can freeze easily and are typically solid at room temperature. For example, animal fats tallow and lard are high in saturated fatty acid content and are solids. They yield maximum energy during metabolism.

Un-saturated fats. Found in fish and most vegetable oils. They are healthier sources of fat, but still have a lot of calories. Since an unsaturated fat contains fewer carbon-

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hydrogen bonds than a saturated fat, they do not solidify and will yield slightly less energy during metabolism compared to saturated fats. e.g. Olive and linseed oils.

Un-saturated fatty acids are classified as Monounsaturated fats and polyunsaturated fats and are derived from vegetables and plants.

o Monounsaturated fats (MUF) are liquid at room temperature but begin to solidify at cold temperatures. This type of fat is preferable to other types of fat and can be found in olives, olive oil, nuts, peanut oil, canola oil and avocados. Some studies have shown that these kinds of fats can actually lower LDL (bad) cholesterol and maintain HDL (good) cholesterol.

o Polyunsaturated fats (PUF) are also liquid at room temperature. These are found in safflower, sesame, corn, cottonseed and soybean oils. This type of fat has also been shown to reduce levels of LDL cholesterol, but too much can also lower your HDL cholesterol.

Trans fats. These are largely artificial fats. A small amount of trans fats occur naturally in meat and dairy products. Trans fats are made by a chemical process called partial hydrogenation. Liquid vegetable oil (an otherwise healthy monounsaturated fat) is packed with hydrogen atoms and converted into a solid fat. It was found suitable for use in food industry because of its high melting point, creamy, smooth texture and reusability in deep-fat frying. They were considered as a healthier alternative to saturated fats: Numerous studies now conclude that trans fats are actually worse. While saturated fats raise total and bad (LDL) cholesterol levels, Trans fats do the same, but they also strip levels of good (HDL) cholesterol, the kind that helps unclog arteries. Trans fats also increase triglyceride levels in the blood, adding to our risk of cardiovascular disease.

Cholesterol. is a fat produced by the liver and is crucial for normal body functioning. Cholesterol exists in the outer layer of every cell in our body and has many functions. Many people get additional cholesterol by eating meat and dairy products. Too much dietary intake may raise blood cholesterol levels, and lead to heart disease. Cholesterol is transported through the bloodstream by lipoproteins.

What are normal cholesterol levels?

The NCEP guideline recommends the following values for Cholesterol.

LDL Cholesterol (mg/dl)

<100 Optimal

100-129Near

Optimal

130-159Borderline

High160-189 High

> 190 Very High

Total Cholesterol (mg/dl)

<200 Desirable200-239 Borderline

>=240 High risk

HDL Cholesterol (mg/dl)

<40Low

(undesirable

>60Hight

(desirable)

Triglycerides (mg/dl)

<150 Normal

150-199Borderline High

200-499 High>500 Very High

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What are the functions of cholesterol?

o It builds and maintains cell membranes (outer layer)o It is essential for determining which molecules can pass into the cell and which

cannot (cell membrane permeability)o It is involved in the production of sex hormones (androgens and estrogens)o It is essential for the production of hormones released by the adrenal glands

(cortisol, corticosterone, aldosterone, and others)o It aids in the production of bileo It converts sunshine to vitamin Do It is important for the metabolism of fat soluble vitamins, including vitamins A,

D, E, and Ko It insulates nerve fibers

Cholesterol is carried in the blood by molecules called lipoproteins. A lipoprotein is any complex or compound containing both lipid (fat) and protein. There are three main types of lipoproteins

o LDL (low density lipoprotein) - often referred to it as bad cholesterol. LDL carries cholesterol from the liver to cells. If too much is carried, too much for the cells to use, there can be a harmful buildup of LDL. This lipoprotein can increase the risk of arterial disease if levels rise too high. Most human blood contains approximately 70% LDL - this may vary, depending on the person.

o HDL (high density lipoprotein) - people often referred to it as good cholesterol. Experts say HDL prevents arterial disease. HDL does the opposite of LDL -HDL takes the cholesterol away from the cells and back to the liver. In the liver it is either broken down or expelled from the body as waste.

o Triglycerides - these are the chemical forms in which most fat exists in the bodyas well as in food. They are present in blood plasma. Triglycerides, in association with cholesterol, form the plasma lipids (blood fat). Triglycerides in plasma originate either from fats in our food, or are made in the body from other energy sources, such as carbohydrates. Calories we consume but are not used immediately by our tissues are converted into triglycerides and stored in fat cells. When our body needs energy and there is no food as an energy source, triglycerides will be released from fat cells and used as energy -hormones control this process.

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OMEGA -3 FATTY ACIDS

Omega-3 fatty acids are a class of essential polyunsaturated fatty acids that cannot be synthesised by our body but is vital for metabolism. Foods high in omega-3 fatty acids include salmon, halibut, sardines, albacore, trout, herring, walnut, flaxseed oil, and canola oil. Other foods that contain omega-3 fatty acids include shrimp, clams, light chunk tuna, catfish, cod, and spinach.

Nutritionally important Omega−3 fatty acids include α-linolenic acid (ALA),eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA), all of which are polyunsaturated. These fatty acids are known to reduce the risk of coronary heart disease, boost immune systems and also have anti cancer properties. Also known as polyunsaturated fatty acids (PUFAs), omega-3 fatty acids play a crucial role in brain function, as well as normal growth and development. They have also become popular because they may reduce the risk of heart disease. Omega-3 fatty acids can also reduce inflammation and may help lower risk of chronic diseases such as heart disease, cancer, and arthritis. Omega-3 fatty acids are highly concentrated in the brain and appear to be important for cognitive (brain memory and performance) and behavioral function. In fact, infants who do not get enough omega-3 fatty acids from their mothers during pregnancy are at risk for developing vision and nerve problems. Symptoms of omega-3 fatty acid deficiency include fatigue, poor memory, dry skin, heart problems, mood swings or depression, and poor circulation.

What are the benefits of omega-3 fatty acids?

Scientific evidence is mounting that fish oil (predominantly omega-3 fatty acids) can reduce the risk of sudden cardiac death. Some scientists also believe that omega-3 fatty acids can improve one's blood lipid (cholesterol and triglyceride) levels and decrease the risk of coronary heart disease.

Omega-6 fatty acids are a class of essential polyunsaturated fatty acids with the initial double bond in the sixth carbon position from the methyl group (hence the "6"). Examples of foods rich in omega-6 fatty acids include corn, safflower, sunflower, soybean, and cottonseed oil.

Omega-3 and omega-6 fatty acids are also referred to as n-3 and n-6 fatty acids, respectively.

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OMEGA -6 FATTY ACIDS

Omega-6 fatty acids are considered essential fatty acids: They are necessary for human health but the body can' t make them -- you have to get them through food.

Along with omega-3 fatty acids, omega-6 fatty acids play a crucial role in brain

function, as well as normal growth and development. Also known as polyunsaturated fatty acids (PUFAs), they help stimulate skin and hair growth, maintain bone health,

regulate metabolism, and maintain the reproductive system.

A healthy diet contains a balance of omega-3 and omega-6 fatty acids. It is suggestedthat greater health might be achieved if a 4:1 ratio of Omega-6 and Omega-3 is used.

Omega-3 fatty acids help reduce inflammation, and some omega-6 fatty acids tend to promote inflammation. In fact, some studies suggest that elevated intakes of omega-6

fatty acids may play a role in Complex Regional Pain Syndrome.

There are several different types of omega-6 fatty acids, and not all promote inflammation. Most omega-6 fatty acids in the diet come from vegetable oils, such as

linoleic acid (LA). Be careful not to confuse this with alpha-linolenic acid (ALA), an

omega-3 fatty acid. Linoleic acid is converted to gamma-linolenic acid (GLA) in the body. It is then further broken down to arachidonic acid (AA). GLA is found in several

plant based oils, including evening primrose oil (EPO), borage oil, and black currant seed oil.

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Phytochemicals

Phytochemicals are non-nutritive plant chemicals that have protective or disease preventive properties. They are nonessential nutrients i.e not required by the human body for sustaining life. Plants produce these chemicals to protect themselves but in recent studies it is shown that they can also protect humans against diseases. There are more than thousand phytochemicals including lycopene in tomatoes, isoflavonesin soya and flavanoids in fruits. Different phytochemicals work differently and includes:

Antioxidant - Most phytochemicals have antioxidant activity and protect our cells against oxidative damage and reduce the risk of developing certain types of cancer. Phytochemicals with antioxidant activities are: allyl sulfides (onions, leeks, garlic), carotenoids (fruits, carrots), flavonoids (fruits, vegetables), polyphenols (tea, grapes).

Hormonal action - Isoflavones, found in soya imitate human estrogens and help reduce menopausal symptoms and osteoporosis.

Stimulation of enzymes - Indoles, which are found in cabbages, stimulate enzymes that make the estrogen less effective and could reduce the risk for breast cancer. Other phytochemicals, which interfere with enzymes, are protease inhibitors (soya and beans), terpenes (citrus fruits and cherries).

Interference with DNA replication - Saponins found in beans interfere with the replication of cell DNA, thereby preventing the multiplication of cancer cells. Capsaicin, found in hot peppers, protects DNA from carcinogens.

Anti-bacterial effect - The phytochemical allicin from garlic has anti-bacterial properties.

Physical action - Some phytochemicals bind physically to cell walls thereby preventing the adhesion of pathogens to human cell walls. Proanthocyanidins are responsible for the anti-adhesion properties of cranberry. Consumption of cranberries will reduce the risk of urinary tract infections and will improve dental health.

How do we get enough phytochemicals?

Foods containing phytochemicals are already part of our daily diet. In fact, most foods contain phytochemicals except for some refined foods such as sugar or alcohol. Some foods, such as whole grains, vegetables, beans, fruits and herbs, contain many phytochemicals. The easiest way to get more phytochemicals is to eat more fruit (blueberries, cranberries, cherries, apple) and vegetables (cauliflower, cabbage, carrots, broccoli). It is recommended take daily at least 5 to 9 servings of fruits or vegetable. Fruits and vegetables are also rich in minerals, vitamins and fibre and low in saturated fat.

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MICRONUTRIENTS

1. Vitamins

Vitamins are essential nutrients that your body needs to help the cells function properly. They contain no calories and do not provide the body with energy but they are required for a number of important functions. Vitamins are distinguished from minerals because they are organic compounds (they come from plants and animals) whereas minerals are inorganic (they come from the soil and water).and are required in small quantities for growth and for maintaining good health. Vitamins cannot be synthesized in the body in sufficient quantities and must be obtained from the diet. Some of the vitamins serve only one function in the body, while other vitamins serve a variety of unrelated functions. Therefore, some vitamin deficiencies tend to result in one type of defect, while other deficiencies result in a variety of problems.

Vitamins are used for three reasons.

o To treat a vitamin deficiency

o Prevent the development of an expected deficiency.

o Reduce the risk of diseases that may occur even when vitamin deficiency cannot be detected.

List of vitamins

Each vitamin is typically used in multiple reactions, and, therefore, most have multiple

functions.

Vitamin Chemical name Solubility RDA Deficiency disease

Vitamin A Retinol Fat 900 µg Night-blindness,

Vitamin B1 Thiamine Water 1.2 mg Beriberi

Vitamin B2 Riboflavin Water 1.3 mg Ariboflavinosis

Vitamin B3 Niacin Water 16.0 mg Pellagra

Vitamin B5 Pantothenic acid Water 5.0 mg Paresthesia

Vitamin B6 Pyridoxine Water 1.3–1.7 mg Anemia

Vitamin B7 Biotin Water 30.0 µg Dermatitis, enteritis

Vitamin B9 Folic acid Water 400 µg Megaloblastic anemia

Vitamin B12 Cyanocobalamin Water 2.4 µg Megaloblastic anemia

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Vitamin C Ascorbic acid Water 90.0 mg Scurvy

Vitamin D Cholecalciferol Fat 5.0 µg–10 µg Rickets

Vitamin E Tocopherols Fat 15.0 mgDeficiency is very rare; mild hemolytic anemia in newborn infants

Vitamin K Phylloquinone Fat 120 µg Bleeding diathesis

Vitamins are classified as either water-soluble or fat-soluble. There are a total of 13 vitamins: 4 fat-soluble (A, D, E, and K) and 9 water-soluble (8 B vitamins and vitamin C).

Fat Soluble Vitamins: Fat-soluble vitamins are soluble in fat and absorbed through the intestinal tract with the help of bile acids. Once absorbed, the body stores them in fat. When required, the vitamins are released form the fat and used. These vitamins should not be consumed in excess because they are more likely to accumulate in the body leading to hypervitaminosis.

Vitamin A

Vitamin A is a group of compounds that play an important role in vision, bone growth, reproduction, cell division & cell differentiation. Vitamin A helps regulate the immune system to prevent or fight off infections by making white blood cells that destroy harmful bacteria and viruses. Vitamin A also may help lymphocytes fight infections more effectively. Vitamin A promotes healthy surface linings of the eyes and the respiratory, urinary, and intestinal tracts. When those linings break down, it becomes easier for bacteria to enter the body and cause infection. Vitamin A also helps the skin and mucous membranes function as a barrier to bacteria and viruses.In general, there are two categories of vitamin A, depending on whether the food source is an animal or a plant.

Vitamin A found in foods that come from animals is called preformed vitamin A. It is absorbed in the form of retinol, one of the most usable (active) forms of vitamin A. Sources include liver, whole milk, and some fortified food products. Retinol can be made into retinal and retinoic acid (other active forms of vitamin A) in the body.

Vitamin A that is found in colorful fruits and vegetables is called provitamin Acarotenoid. They can be made into retinol in the body. Common provitamin A carotenoids found in foods that come from plants are beta-carotene, alpha-carotene, and beta-cryptoxanthin[. Among these, beta-carotene is most efficiently made into retinol. Alpha-carotene and beta-cryptoxanthin are also converted to vitamin A, but only half as efficiently as beta-carotene

Vitamin D

Vitamin D aids calcium absorption, bone growth and remodeling and healthy neuromuscular and immune function. When human skin is exposed to ultraviolet B radiation from the sun it converts cutaneous 7-dehydrocholesterol into vitamin D, but food sources of vitamin D are relatively limited. Vitamin D from food sources comes in two varieties: vitamin D3, which is found in animal products, and vitamin D2 which is

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found in mushrooms. Mushrooms artificially exposed to ultraviolet light have even higher levels of vitamin D2. Foods that don't normally contain high levels of vitamin D are also fortified with vitamin D3 to supplement dietary intake. Animal sources of vitamin D include cod liver oil, salmon, mackerel, tuna, fortified milk and juices, sardines, beef liver, fortified cereals and eggs.

Vitamin E

Vitamin E actually refers to eight different chemical compounds with antioxidant properties, but only one of the eight is considered to be bioavailable to humans. Theoretically, antioxidants help the body fight free radicals, or molecules with an unshared electron that can damage cells and may play a role in the development of heart disease and cancer. Adults should consume 22.4 IU of vitamin E per day. Wheat germ, nuts, seeds, green leafy vegetables, kiwi, mango and tomatoes are among the best sources of vitamin E.

Vitamin KVitamin K promotes normal blood clotting and healthy bone growth, according to Colorado State University. The RDA of vitamin K is 120 mcg per day for adult males and 90 mcg per day for adult females. Vitamin K is produced by intestinal bacteria, but can also be found in green leafy vegetables, soybean oil, cottonseed oil, olive oil and canola oil.

Water soluble Vitamins: Water-soluble vitamins dissolve easily in water and are easily absorbed and excreted from the body. Because they are not readily stored, consistent daily intake is important. They get destroyed by over cooking.

Major food sources of Water-Soluble Vitamins

Grains Fruits Vegetables Meats, Eggs Legumes, Nuts, Seeds Milk, Dairy

Thiamin X X X

Riboflavin X X

Niacin X X X

Biotin X X X

Pyridoxine X X X

Pantothenic acid X X X X X X

Vitamin B12 X X

Folate X X

Vitamin C X X

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Water-soluble vitamins and their characteristics

Sources Major functions Deficiency symptoms Stability in foods

VITAMIN C (Ascorbic Acid)

Citrus fruits, broccoli, strawberries, melon, green pepper, tomatoes, dark green vegetables, potatoes.

Formation of collagen, helps hold them together; wound healing; maintaining blood vessels, bones, teeth; absorption of iron, calcium, production of brain hormones, immune factors; antioxidant.

Bleeding gums; wounds don't heal; bruise easily; dry, rough skin; scurvy; sore joints and bones; increased infections.

Most unstable under heat, drying, storage; very soluble in water, leaches out of some vegetables during cooking; alkalinity (baking soda) destroys vitamin C.

VITAMIN B1 (Thiamine)

Pork, liver, whole grains, enriched grain products, peas, meat, legumes.

Helps release energy from foods; promotes normal appetite; important in function of nervous system.

Mental confusion; muscle weakness, wasting; edema; impaired growth; beriberi.

Losses depend on cooking method, length, alkalinity of cooking medium; destroyed by sulfite used to treat dried fruits such as apricots; dissolves in cooking water.

VITAMIN B2 (Riboflavine)

Liver, milk, dark green vegetables, whole and enriched grain products, eggs.

Helps release energy from foods; promotes good vision, healthy skin.

Cracks at corners of mouth; dermatitis around nose and lips; eyes sensitive to light.

Sensitive to light; unstable in alkaline solutions.

Niacin (Nicotinamide)

Liver, fish, poultry, meat, peanuts, whole and enriched grain products.

Energy production from foods; aids digestion, promotes normal appetite; promotes healthy skin, nerves.

Skin disorders; diarrhea; weakness; mental confusion; irritability.

VITAMIN B6 (Pyridoxine)

Pork, meats, whole grains and cereals, legumes, green, leafy vegetables.

Aids in protein metabolism, absorption; aids in red blood cell formation; helps body use fats.

Skin disorders, dermatitis, cracks at corners of mouth; irritability; anemia; kidney stones; nausea; smooth tongue.

Considerable losses during cooking.

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Folic Acid (Folacin)

Liver, kidney, dark green leafy vegetables, meats, fish, whole grains, fortified grains and cereals, legumes, citrus fruits.

Aids in protein metabolism; promotes red blood cell formation; prevents birth defects of spine, brain; lowers homocystein levels and thus coronary heart disease risk.

Anemia; smooth tongue; diarrhea.

Easily destroyed by storing, cooking and other processing.

VITAMIN B12 (Cynacobalamin)

Found only in animal foods: meats, liver, kidney, fish, eggs, milk and milk products, oysters, shellfish.

Aids in building of genetic material; aids in development of normal red blood cells; maintenance of nervous system.

Pernicious anemia, anemia; neurological disorders; degeneration of peripheral nerves that may cause numbness, tingling in fingers and toes.

Pantothenic Acid

Liver, kidney, meats, egg yolk, whole grains, legumes; also made by intestinal bacteria.

Involved in energy production; aids in formation of hormones.

Uncommon due to availability in most foods; fatigue; nausea, abdominal cramps; difficulty sleeping.

About half of pantothenic acid is lost in the milling of grains and heavily refined foods.

Biotin

Liver, kidney, egg yolk, milk, most fresh vegetables, also made by intestinal bacteria.

Helps release energy from carbohydrates; aids in fat synthesis.

Uncommon under normal circumstances; fatigue; loss of appetite, nausea, vomiting; depression; muscle pains; anemia.

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2. Minerals

Dietary minerals (also known as mineral nutrients) are the chemical elements required by living organisms, other than the four elements carbon, hydrogen, nitrogen, and oxygen present in commonorganic molecules. Examples of mineral elements include calcium, magnesium, potassium, sodium, zinc, and iodine

Minerals are required by the body for building bones, making hormones and regulating heartbeat etc There are two types of minerals: macrominerals and trace minerals. Macrominerals are minerals where the body needs in larger amounts. Theseinclude calcium, phosphorus, magnesium, sodium, potassium, chloride and sulfur. Microminerals are those where the body needs just small amounts of trace minerals. These include iron, manganese, copper, iodine, zinc, cobalt, fluoride and selenium.

Minerals and their function

CalciumMacro Builds bones and teeth, muscle contraction, heart action, nerve

impulses, blood clotting

SulfurMacro Helps in protein synthesis which is needed for healthy hair and

nails.

MagnesiumMacro Bones, liver, muscles, transfer of intercellular water, alkaline

balance, neuromuscular activity

PhosphorusMacro Builds bones and teeth, energy production, acid-base balance,

necessary in metabolism and cell membranes, calcium absorption

Sodium Macro Electrolyte balance, body fluid volume, nerve impulse condition

ChlorideMacro Needed to maintain adequate amounts of water in different parts of

the body

PotassiumMacro Cell membrane potential, nerve impulse conduction, heart rhythm,

acid base balance

ZincTrace Protein synthesis, carbon dioxide transport, sexual function, insulin

storage, carbohydrate metabolism, wound healing

CopperTrace Hemoglobin formation, production of RNA, elastic tissue formation,

cholesterol utilization, oxidase enzyme activator

IronTrace Hemoglobin formation, electron transport, oxygen transport,

enzyme activator

ChromiumTrace Glucose utilization, insulin activity, heart muscle, cholesterol

utilization

Manganese Trace Carbohydrate metabolism, protein metabolism, connective tissue,

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joint fluid production, nerve tissue, Vitamin B1 utilization

Molybdenum Trace Enzyme activator, uric acid formation, oxidative enzymes

SeleniumTrace Peroxidase scavenger, glutathione peroxidase, anti-carcinogenic,

Vitamin F synergist

SiliconTrace Bone formation, collagen formation, cartilage formation, elastic

tissue

Boron Trace Reduces calcium loss

VanadiumTrace Strength of bones and teeth, lowers blood lipids, inhibits cholesterol

synthesis

Tin Trace Growth, protein synthesis

Nickel Trace Activates some liver enzymes

The body contains many different minerals. Minerals by themselves are inactive chemical elements. But in the body, minerals are used for many different purposes including:

o Development of bones and teeth.o Maintaining acid-base balance thereby to keep the body pH neutral.o Regulating body processes, such as in enzyme systems.o Help in nerve impulse transmission and muscle contraction.o Help release energy from food.

Minerals do not work alone but work in balance with one other as well as with the metabolism of proteins, carbohydrates, fats and vitamins. When one mineral is in excess, it steals from others, thereby causing a chain-reaction of deficiencies.

Excessive Calcium Loss of Magnesium & Zinc

Excessive Sodium & Potassium Deficiency of Calcium & Magnesium

Excessive Calcium & Magnesium Deficiency of Sodium & Potassium

Excessive Sodium Loss of Potassium

Excessive Potassium Loss of Sodium

Excessive Copper Loss of Zinc

Excessive Zinc Loss of Copper & Iron

Excessive Phosphorus Loss of Calcium

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Routes of administration of food supplements

Parenteral nutrition (PN) is feeding a person intravenously, bypassing the usual process of eating and digestion. The person receives nutritional formulas that contain nutrients such as salts, glucose, amino acids, lipids and added vitamins. It is called total parenteral nutrition (TPN) or total nutrient admixture (TNA) when no food is given by other routes.

TPN may be the only feasible option for nutrition patients who do not have a functioning gastrointestinal tract or who have disorders requiring complete bowel rest, including bowel obstruction, short bowel syndrome, prolonged diarrhea regardless of its cause, high-output fistula, some stages of Crohn's disease or ulcerative colitis, and certain pediatric GI disorders including congenital GI anomalies.

TPN is associated with complications including infections, blood clots, fatty liver etc. Therefore, TPN administration should follow asceptic techniques and the treatment needs individualisation.

Enteral Nutrition is feeding patients through a tube to provide nutrition who otherwisecannot obtain nutrition by swallowing. The process of feeding is called enteral feeding or tube feeding.

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Placement of the tube may be temporary for the treatment of acute conditions or lifelong in the case of chronic disabilities. A variety of feeding tubes is used in medical practice and is usually made of polyurethane or silicone. They are classified by site of insertion and intended use.

1. Nasogastric feeding or NG-tube is passed through the nostril down the esophagus and into the stomach. This type of feeding tube is generally used for short term feeding, usually only 2 weeks maximum.

2. Gastric feeding tube or G-tube is a tube inserted through a small incision in the abdomen into the stomach and is used for long-term enteral nutrition. One type is the percutaneous endoscopic gastrostomy (PEG) tube. It is passed through the mouth and esophagus into the stomach.

Gastric feeding tubes are suitable for long-term use, though they sometimes need to be replaced if used long term. The G-tube can be useful where there is difficulty with swallowing because of neurologic or anatomic disorders (stroke, esophageal atresia, tracheoesophageal fistula), and to avoid the risk of aspiration pneumonia. However, in patients with advanced dementia or adult failure to thrive it does not decrease the risk of pneumonia.

3. Jejunostomy feeding tube or the J-tube is a tube surgically inserted through the abdomen and into the jejunum (the second part of the small intestine). The procedure is called a jejunostomy.

Oral administration (per os) is a route of administration where the nutrition is taken through the mouth either mixed with water or milk. This is the most preferred route as it is easy and convenient to administer.