Nutrition I

1
Nutrition I

• Macronutrients

2
Role of Nutrients in Diet

• Growth and development
• Provide energy
• Regulate metabolism

3
Classes of Nutrients

• Carbohydrates
• Proteins
• Fats
• Vitamins
• Minerals
• Water

4
Carbohydrates (3 types)

• Monosaccharides glucose, fructose, galactose
• Disaccharides
• sucrose glucose fructose
• simple (pop, candy, sweets)
• Maltose glucose glucose
• Lactose glucose galactose
• Polysaccharides

5
Carbohydrates

• Digestion convert all CHO to glucose
• Glucose fates
• Cell energy glycolysis
• Stored as glycogen in muscle and liver
• Converted to fat for energy storage
• Carbon skeleton for synthesis of non-essential
  amino acids

6
Carbohydrates

• Two types of polysaccharides
• Animal
• Plant
• Two forms of plant polysaccharides
• Starch complex carbohydrate (pasta, rice,
  breads)
• Fiber (cellulose, gums, hemicellulose, pectin)

7
Ways to Get More Fiber

• Eat more fruits and vegetables
• Eat whole grain foods

8
A Grain of Wheat
9
Animal Polysaccharide

• Glycogen the major animal polysaccharide
• Storage (80 kg person) 500 grams
• 400 g muscle
• 100 g liver
• Glycogen ? glucose glycogenolysis
• Amino acid ? glucose gluconeogenesis
• Insulin ? ? or ? blood sugar?
• Glucagon ? liver glycogenolysis gluconeogenesis
  ? ? or ? blood sugar?

10
Carbohydrate Role

• Energy Source
• Protein Sparer
• Metabolic Primer (fats burn in carbohydrate fire)
• Fuel for central nervous system

11
Recommended Carbohydrate

• What is the typical amount of carbohydrate
  consumed as of total calories?
• What is the recommended carbohydrate intake as
  of total calories for physically active man and
  woman?

12
Trends in Carbohydrate Consumption
13
Carbohydrate Confusion

• Consumption of low-fiber processed starches
  stimulates overproduction of insulin which
  increases TGs fat synthesis
• Variables for metabolic syndrome
• Abdominal fatness
• Triacylglycerides
• Low HDL
• High BP
• High fasting blood glucose

14
Carbohydrate Confusion

• Glycemic index compares equal quantities of
  carbohydrate containing food
• Glycemic load quantifies overall glycemic effect
  of a portion of food
• Low glycemic index foods - slower passage of food
  into small intestine why

15
Carbohydrate Utilization in Exercise

• What is the primary fuel during intense exercise
  of short duration?
• What is the utilization of CHO during initial
  stage of moderate but prolonged?
• What is the utilization of CHO during middle
  stage of moderate but prolonged?
• What is the utilization of CHO during last stage
  of moderate but prolonged?

16
Carbohydrate Use in Exercise
17
Lipids

• Simple
• Most common simple fat in body?
• Molecular structure of simple lipid.
• Saturated fatty acid characteristic?
• Food sources of saturated fatty acids.
• Beef, lamb, pork, chicken
• Egg yolk
• Dairy fats cream, milk, butter, and cheese

18
Fatty Acids

• Saturated (animal)
• straight
• Unsaturated (plant)
• bent
• Poly-unsaturated
• Mono-unsaturated

19
Dietary Fat Recommendations

• Less than 30 of calories in diet from fat
• Less than 10 of calories in diet should be
  saturated fat
• Avoid trans form of unsaturated fatty acid

20
Composition of Oils ()

• Type Sat Poly Mono
• safflower 9 75 16
• sunflower 10 66 24
• corn 13 59 28
• soybean 14 58 28
• sesame 14 42 44
• peanut 17 32 51
• palm 49 9 42
• olive 14 8 78
• canola 7 35 58

21
Recommended Dietary Intake
22
Actual Dietary Intake (Average American)
23
Caloric Content of Foods

• Atwater factors
• Carbohydrates 4 cal/g
• Protein 4 cal/g
• Fats 9 cal/g
• Alcohol 7 cal/g

24
What is Baloney?
25
What about Sliced Turkey?
26
Recommendations to Decrease Intake of Fat

• Minimize "fast" foods
• Minimize processed foods
• Use better cuts of meats
• Use low fat alternatives
• Decrease use of condiments
• Eat lower fat snacks

27
Lipoproteins

• High Density Lipoproteins
• Low Density Lipoproteins

What are the dietary implications of these
lipoproteins?
28
Protein (Amino Acids - 20)

• Non-essential (11)
• Essential (9)
• Valine
• Leucine
• Isoleucine
• Threonine
• Lycine
• Histidine
• Phenylalanine
• Tryptophan
• Methionine

29
Sources of Protein

• Animal (complete)
• meats, dairy
• Vegetable (incomplete)
• beans, nuts, legumes, grains

30
Proteins Role in the Body

• Primary constituent for plasma membrane and
  internal cellular material
• Comprise hair, skin, nail, bone, tendons,
  ligaments, muscles, enzymes
• Regulate acid-base quality of body fluids

31
Metabolic Fate of Protein

• Body tissues obtain a.a. from blood to synthesize
  proteins specific to cell needs
• Tissue
• Enzymes
• Creatine from nitrogen
• Body cells cannot store excess amino acids
• Deamination removes amino group (NH2)

32
Fate of Protein (contd)

• Deamination leaves alpha-ketoacid
• Liver forms ammonia from the N, which is
  converted to urea and eliminated by kidneys
• Alpha-ketoacid fates
• Recombined with another amino group to form
  another amino acid
• Channeled into metabolic pathway as fat or
  carbohydrate

33
Protein Requirements

• RDA average .8 g/kg/day
• RDA athlete 1.2-1.6 g/kg/day

High levels of protein intake above 2 g/kg/day
can be harmful to the body