1. Chapter 4 Carbohydrates: Sugar, Starch, Glycogen, and Fiber
Nutrition: Concepts & Controversies, 12e Sizer/Whitney

2. Learning Objectives
Describe the major types of carbohydrates, and identify their food sources.
Describe the various roles of carbohydrates in the body, and explain why avoiding dietary carbohydrates may be ill-advised.
Summarize how fiber differs from other carbohydrates and how fiber may contribute to health.

3. Learning Objectives
Describe the scope of the U.S. diabetes problem and educate someone about the long- and short-term effects of untreated diabetes and prediabetes.
Name components of a lifestyle plan to effectively control blood glucose and describe the characteristics of a diet that can assist in managing type 2 diabetes.

4. Carbohydrates Ideal nutrients
Energy needs
Feed brain and nervous system
Keep digestive system fit
Keep your body lean
Digestible and indigestible carbohydrates
Complex vs. simple carbohydrates

5. A Close Look at Carbohydrates
Contain the sun’s radiant energy
Green plants
Photosynthesis
Glucose
Plants do not use all of the energy stored in their sugars
Carbohydrate-rich foods
Plants
Milk

6. Carbohydrate – Mainly Glucose – Is Made by Photosynthesis

7. A Close Look at Carbohydrates - Sugars
Six sugar molecules
Monosaccharides
Glucose, fructose, galactose
Disaccharides
Lactose, maltose, and sucrose
Digestion of mono- and disaccharides
Chemical names end in -ose

8. How Monosaccharides Join to Form Disaccharides

9. A Close Look at Carbohydrates – Starch
Polysaccharides
Starch
Plant’s storage form of glucose
Glycogen
Fiber
Nutrition
For a plant
For a human

10. How Glucose Molecules Join to Form Polysaccharides

11. A Close Look at Carbohydrates – Glycogen
Storage form of glucose
Animal bodies
Chains are longer than starch
More highly branched
Undetectable in meats

12. A Close Look at Carbohydrates - Fibers
Human digestive enzymes cannot break bonds
Bacteria in large intestine
Fermentation
Soluble vs. insoluble fibers

13. The Need for Carbohydrates
Critical energy source
Nerve cells and brain
Preferred dietary sources
Starchy whole foods
Complex carbohydrates
Vital roles in the functioning body

14. The Need for Carbohydrates
Weight loss
Caloric contribution
Conversion into fat storage
Refined sugars
Increase fiber-rich whole foods
Reduce refined white flour and added sugars

15. Characteristics, Sources, and Health Effects of Fibers

16. Fiber Composition of Common Foods

17. Why Do Nutrition Experts Recommend Fiber-Rich Foods?
Lower cholesterol and heart disease risk
Complex carbohydrates
More than just fiber
Viscous fiber
Cholesterol synthesis
Blood glucose control
Whole grains
Soluble fibers

18. One Way Fiber in Food May Lower Cholesterol in the Blood

19. Why Do Nutrition Experts Recommend Fiber-Rich Foods?
Maintenance of digestive tract health
All kinds of fiber
Ample fluid intake
Benefits of fiber
Constipation, hemorrhoids, appendicitis, diverticulosis

20. Diverticula

21. Why Do Nutrition Experts Recommend Fiber-Rich Foods?
Digestive tract cancer and inflammation
Ways fiber works against cancer
Dilution
Folate
Resident bacteria
Butyrate
Recommended dietary sources
Healthy weight management
Appetite control

22. Fiber Recommendations and Intakes
Few people in U.S. meet recommendations
20-35 grams of fiber daily
Based on energy needs, age, and gender
Adding fiber to diet
Too much fiber?
Dangers of excess
Binders in fiber
Chelating agents
Cause of deficiencies

23. Usefulness of Carbohydrates

24. Refined, Enriched, and Whole-Grain Foods
Bread supplies much carbohydrate for many people
Kernel (whole grain) has four main parts
Germ
Endosperm
Bran
Husk

25. Refined, Enriched, and Whole-Grain Foods
U.S. Enrichment Act of 1942
Required additives
Addition in 1996
Advantages of whole grains vs. enriched grains
Finding the whole grains in foods

26. Bread Labels Compared

27. From Carbohydrates to Glucose – Digestion & Absorption
Starch and disaccharides are broken down
Monosaccharides for absorption
Starch
Begins in the mouth
Splits starch into maltose
Digestion ceases in the stomach
Digestion resumes in small intestine
Pancreas
Resistant starch

28. How Carbohydrate in Food Becomes Glucose in the Body

29. Why Do Some People Have Trouble Digesting Milk?
Ability to digest milk carbohydrates varies
Lactase
Made by small intestine
Symptoms of intolerance
Nausea, pain, diarrhea, and gas
Milk allergy
Nutritional consequences
Milk tolerance and strategies

30. The Body’s Use of Glucose
Basic carbohydrate unit used for energy
Body handles glucose judiciously
Maintains an internal supply
Tightly controlling blood glucose concentrations
Brain, nervous system, red blood cells

31. Splitting Glucose for Energy
Glucose is broken in half
Can reassemble
Broken into smaller molecules
Irreversible
Two pathways

32. Splitting Glucose for Energy
Glucose can be converted to fat
Fat cannot be converted to glucose
Dependence on protein when insufficient carbohydrate
Protein-sparing action
Ketosis
Shift in body’s metabolism
Disruption of acid-base balance
DRI minimum of digestible carbohydrate

33. How Is Glucose Regulated in the Body?
Two safeguard activities
Siphoning off excess blood glucose
Replenishing diminished glucose
Two hormones
Insulin
Signals body tissues to take up glucose
Glucagon
Triggers breakdown of glycogen
Epinephrine

34. Handling Excess Glucose
Body tissue shift
Burn more glucose
Fat is left to circulate and be stored
Carbohydrate storage as fat
Liver breakdown and assembly
Costs a lot of energy
Weight maintenance
Dietary importance and composition

35. Glycemic Index of Food Elevation of blood glucose and insulin Diabetes
Food score compared to standard food
Diabetes
Glycemic load (GL)
Lower GL = less glucose guild up and less insulin needed
Limitations of glycemic index
Resist notion of “good” or “bad” foods

36. Glycemic Index of Selected Foods

37. Diabetes Prevalence of diabetes Prediabetes Perils of diabetes Adults
Children
Prediabetes
Importance of testing
Perils of diabetes
Toxic effects of excess glucose
Inflammation
Circulation problems

38. Prevalence of Diabetes Among Adults in the United States

39. Type 1 and 2 Diabetes Compared

40. An Obesity-Diabetes Cycle

41. Accusation 1: Carbohydrates Are Making Us Fat
Americans are fatter
Greater consumption of calories
per day
Epidemiological studies
Weight loss

42. Percentage of Calories from Energy Nutrients, U.S., 1977-2006

43. Accusation 4: High-Fructose Corn Syrup Harms Health
Villainy has been exaggerated
Nature of HFCS
Half of added sugar in U.S. food supply
Obesity
HCFS not a proven cause
Liquid sugar and calorie control
Appetite regulation
Fructose does not stimulate insulin release

44. Accusation 4: High-Fructose Corn Syrup Harms Health
Effects on lipid metabolism
Fructose causes fats to accumulate in blood and liver
Metabolic activities of concern