Focus on: Carbohydrates

Nutrients: Energy Yielding or Not? Nutrient   Yields  Energy?  

Yes! No!Macronutrients!Carbohydrates! ✔ 4 kcal/gram!Fats! ✔ 9 kcal/gram!Protein! ✔ 4 kcal/gram!Micronutrients!Vitamins! ✔!Minerals! ✔!Miscellaneous!Water! ✔!Alcohol! ✔ 7 kcal/gram!

Concept Check

o 1  gram  carbohydrate  →  4  calories  per  gram  o 1  gram  protein  →  4  calories  per  gram  o 1  gram  fat  →  9  calories  per  gram  o 1  gram  alcohol  →  7  calories  per  gram  o Vitamins  &  minerals  don’t  yield  calories  or  energy  

Overview

Carbohydrates:

Should constitute the majority of kcals in a balanced diet

Provide 4 kcals/gram

Groups of compounds made up of ≥ 1 sugar molecule

Can be abbreviated CHO

Made up of carbon, hydrogen & oxygen

From grains, fruits, vegetables, milk, legumes

Simple Carbohydrates

Monosaccharides

CHO made up of a single sugar unit

Includes glucose, galactose & fructose

Disaccharides

CHO made up of two sugar units

Includes: maltose, sucrose & lactose

Simple Carbohydrates - Monosaccharides & Disaccharides:

Glucose  is  the  most  abundant  monosaccharide  –  it  circulates  in  the  blood  

Galactose  is  a  monosaccharide  –  it  is  the  molecule  that  makes  up  ½  of  milk  sugar  

Fructose  is  a  monosaccharide  –  also  referred  to  as  fruit  sugar  

Image:  Jose  Paolo  S.  Borromeo  

Disaccharides Maltose

Glucose + Glucose

Sucrose

Glucose + Fructose

Also known as:

Lactose

Glucose + Galactose

Also known as:

What does each disaccharide have in common?

Maltose  is  a  disaccharide  –  it’s  formed  when  starch  is  digested  and  is  broken  down  by  salivary  amylase  

Sucrose  is  a  disaccharide  –  also  referred  to  as  table  sugar;  in  US,  it’s  the  only  sweetener  that  can  be  called  “sugar”  on  labels  

Lactose  is  a  disaccharide  –  also  referred  to  as  milk  sugar;  people  with  lactose  intolerance  lack  or  don’t  make  enough  of  the  enzyme  lactase  to  break  down  lactose  

Image:  Jose  Paolo  S.  Borromeo  

Complex Carbohydrates

Glycogen

Storage form of glucose in humans & animals

Where is glycogen stored?

Starch

Storage form of glucose in plants

Complex Carbohydrates: Polysaccharides

Fiber

Indigestible, nonabsorbable plant remnant

How many kcal/gram does fiber yield?

Glycogen  is  a  polysaccharide  made  of  highly  branched  chains  of  glucose  –  branching  allows  for  quick  breakdown  to  glucose  

Starches  consist  of  either  straight  or  branched  chains  of  glucose  –  starchy  foods  include  breads,  legumes  and  starchy  vegetables  

Fiber  is  made  up  of  either  straight  or  branched  chains  of  monosaccharides  –  human  enzymes  can’t  break  sugar  links  

Image:  Jose  Paolo  S.  Borromeo  

Dietary Sources of Carbohydrate

Dairy Milk & Yogurt (12 g/cup) – no CHO in cheese

Fruit Medium-sized piece or ½ cup cut = 15 g CHO

Vegetables Medium-sized or ½ cup cooked = 5 g CHO

Bread 1 oz, 1 slice, ½ cup cooked starch = 15 g CHO

Beans (Legumes, dried beans), 15-20 g CHO/½ cup

Meat No carb

Oil & fat No carb

Sugars 1 tsp = 4 g CHO (1 Tbs = 12 g CHO)

Determining Carbohydrate Needs

Acceptable Macronutrient Distribution Range 45-65% total calories

Recommended Dietary Allowance (Carbohydrate)

0-0.5 y.o. 60 g/day

0.5-1.0 y,o. 95 g/day

1-50+ y.o. 130 g/day

Pregnant 175 g/day

Lactating 210 g/day

What do you notice about a 1 yr old vs. 45 yr. old’s CHO needs?

Application: Carbohydrate Needs

o  23  year  old  male,  elite  athlete,  endurance  runner  o His  daily  esMmated  kcal  needs  are  3,500  kcal/day  o As  he  approaches  compeMMon  –  goal  is  70%  kcal  from  carbohydrate  

How many grams of carbohydrate per day does he need?

Application: Solution

o QuesMon  is  asking  you  grams  of  carb  per  day  o  70%  of  3,500  calories  come  from  carb  o  3,500  X  0.7  (70%)  =  2,450  calories  from  carb  o QuesMon  doesn’t  ask  you  cal  from  carb  –  we  want  grams  of  carb  

o  2,450  calories  from  carb  divided  by  4  cal/g  carb  =  612.5  grams  –  round  to  613  grams  of  carb  per  day  

For More Information o  MedlinePlus,  Carbohydrates:  

h^p://www.nlm.nih.gov/medlineplus/carbohydrates.html    o  CDC,  NutriMon  for  Everyone,  Carbohydrates:  

h^p://www.cdc.gov/nutriMon/everyone/basics/carbs.html    o  FAO,  Carbohydrates  in  human  nutriMon:  

h^p://www.fao.org/docrep/w8079e/w8079e00.htm    o  UCSF  PaMent  EducaMon,  Carbohydrates:  

h^p://www.ucseealth.org/educaMon/carbohydrates/index.html