2. Chapter 4: Carbohydrates

3. Plants Synthesize Glucose

4. “Sugars” Simple-one or two sugar units Monosaccharides Disaccharies Starch or fibers-digestibility Large, more complex structures

5. Monosaccharides Glucose Dextrose or blood sugar Major mono found in the body Fructose Fruit sugar “high fructose corn syrup” Galactose Milk

6. Disaccharides Maltose + maltase= glucose + glucose Fermentation Alcohol production Sucrose + sucrace= glucose+ fructose Sugar Lactose + lactase= galactose + glucose Milk products

7. Complex Carbohydrates Polysaccharides: Starch & glycogen Amylose-long straight chain Amylopectin-highly complex branched chain Dietary fiber-cellulose

8. Glycogen Storage form of CHO for animals & humans Structure similar to amylopectin More sites for enzyme action & storage

9. Dietary Fiber Undigested plant food Body cannot break the bonds Insoluble fiber Cellulos, hemicellulose, lignin Not fermented by the bacteria in the colon Soluble fiber Gum, Pectin, Mucilage Fruit, vegetable, rice bran, psyllium seed

10. Soluble and Insoluble Fiber

11. Health Benefits of Dietary Fiber Absorbs & holds water Soften stool Larger stool promotes peristalsis Promotes regularity-oligosaccharides Lower risk for cardiovascular disease Decrease hemorrhoids and diverticula

12. CHO in Food

14. Types of Sweeteners High-fructose corn syrup cornstarch treated with acid and enzymes conversion of glucose into fructose same degree of sweetness as sucrose cheaper & used in many food products Brown sugar, maple syrup, honey Sugar alcohols (2.6 kcals/gm) Sorbitol & xylitol Absorbed & metabolized slower-fewer calories Large amount causes diarrhea

15. Sugar Substitutes Saccharin-pink Aspartame-blue Sucralose-yellow Neotame Acesulfame-K Tagatose

16. Functions of Carbohydrate Supplies energy & sweetness Protein sparing & prevent ketosis Regulating glucose Glycemic index Glycemic load

17. Recommended CHO Intake No RDA (yet) Consume at least 130 gm to prevent ketosis National Cholesterol Education Program recommends 45-65-0% of kcal from CHO Current intake is ~60% The kind of CHO matters

18. Recommended Dietary Fiber Intake 25 gm of fiber/day for women 38 gm of fiber/day for men About 14 gm/1000 kcals Children: age +5gm/day Ave. U.S. intake: ~16 gm/day Too much fiber (>60 gm/d) will: require extra intake of fluid bind to some minerals develop phytobezoars fills the stomach of a young child quickly

19. Recommendation for Simple Sugar Intake Low nutrient density Recommends no more than 10% of total kcal/day (50 grams) Ave. U.S. intake: 16% of total kcal/day Added to food and beverages during processing Serving sizes! 6.5  20 oz.

20. High Sugar Diets Empty calories Soda replacing milk Calories adding to excess Dental caries exposure to teeth High glycemic index Blood glucose response of a given food Influence by various factors