Nutrition I

1. Nutrition I General Concepts

2. Classes of Nutrients • Carbohydrates • Proteins • Fats • Vitamins • Minerals • Water

3. Carbohydrates (3 types) • Monosaccharides: glucose, fructose, galactose (hexoses) • Disaccharides: • sucrose = glucose + fructose • [simple] (pop, candy, sweets) • Maltose = glucose + glucose • Lactose = glucose + galactose • Polysaccharides

4. 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

5. Carbohydrates • Two types of polysaccharides: • Animal • Plant • Two forms of plant polysaccharides: • Starch [complex carbohydrate] (pasta, rice, breads) • Fiber (cellulose, gums, hemicellulose, pectin) • What’s good about fiber?

6. Ways to Get More Fiber • Eat more fruits and vegetables • Eat whole grain foods

7. BRAN - B vitamins - minerals ENDOSPERM - dietary fiber - starch - protein - some iron and GERM B vitamins - essential fats - minerals - vitamins (B's , E and folacin) A Grain of Wheat

8. Polysaccharides • What is the major animal polysaccharide? • Approximately how many calories of animal polysaccharide can an 80-kg person store? • Where is it stored?

9. Polysaccharides What is glycogenolysis? What is gluconeogenesis? Liver Glycogen Muscle Glycogen Amino Acids Blood Glucose Muscle Glucose Glucose Energy

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. C 100 A 35% R 50% 80 SIMPLE 55% P B E O R H 60 65% C Y E D 50% 40 COMPLEX 45% N R T A 20 T E S 0 1910 1950 1980 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: measures the rise in blood glucose level after ingestion of 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; fiber slows digestion rate

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?

16. Carbohydrate Utilization in Exercise • 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?

17. Lipids • Common simple fat in body: triacylglyceride. • Molecular structure: glycerol & 3 carbon chains (fatty acids)

18. Sources of Fats • Animal (saturated) • Vegetable (unsaturated) • Poly-unsaturated • Mono-unsaturated

19. 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

20. Dietary Fat Recommendations • Less than 30% of calories in diet from fat • Less than 1/3 of dietary fat should be saturated • Less than 10% of total calories from saturated fat

21. PRO PRO (10-15%) CHO FAT (<30%) FAT CHO (55-60%) Recommended Dietary Intake

22. PRO PRO (13%) CHO FAT (40%) CHO (47%) FAT Actual Dietary Intake (Average American)

23. Caloric Content of Foods Carbohydrates 4 cal/g Protein 4 cal/g Fats 9 cal/g Alcohol 7 cal/g

24. Caloric Density Boloney & Turkey 80% "fat free” 98% “fat free” 30 calories/slice 1 gram fat /slice 52 calories / slice 4 grams fat / slice Calories from fat = 4 g/slice x 9 cal/g = 36 cals Calories from fat = 1 g/slice x 9 cal/g = 9 cals Percent of calories from fat = 36 cals /52 cal total = 69% Percent of calories from fat = 9 cals /30 cal total = 30%

25. Compound Lipid: Lipoproteins • High Density Lipoproteins • Low Density Lipoproteins • Very Low Density Lipoproteins What are the dietary implications of these lipoproteins?

26. Lipids Trans Fatty Acids What makes trans FA dangerous? Fish Oils Contain 2 PUFAs Eicosapentaenoic & Docosahexanoic Improve lipid profile

27. Lipids Role in Body • Energy reserve • 150 lb x .25 x 3500 = 131,250 kcals • Protection of vital organs & thermal insulation • Carrier fat soluble vitamins What aspect of lipid causes it to contain more energy than equal weight of CHO?

28. Protein: (Amino Acids - 20) • Non-essential (11) • Essential (9) • Valine • Leucine • Isoleucine • Threonine • Lycine • Histidine • Phenylalanine • Tryptophan • Methionine How does chemical structure of protein differ from carbohydrate and lipid?

29. Sources of Protein • Animal (complete) • meats, dairy • Vegetable (incomplete) • beans, nuts, legumes, grains • What is synthesis of a nonessential amino acid from C, O, and H called?

30. 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 Why is excessive protein harmful? What does body do with excessive protein?