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
Explain how complex carbohydrates are broken down in the digestive tract and absorbed into the body.
Describe how hormones control blood glucose concentrations during fasting and feasting.
Explain the term glycemic index and how it may relate to diet planning.

4. 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.

5. Learning Objectives
Compare the symptoms of postprandial hypoglycemia with those of fasting hypoglycemia, and name some diseases associated with the latter type.
Discuss current research regarding the relationships among dietary carbohydrates, obesity, diabetes, and other ills.

6. 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

7. 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

8. Carbohydrate – Mainly Glucose – Is Made by Photosynthesis

9. 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

10. How Monosaccharides Join to Form Disaccharides

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

12. How Glucose Molecules Join to Form Polysaccharides

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

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

15. 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

16. 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

17. Why Do Nutrition Experts Recommend Fiber-Rich Foods?
Health benefits
Reduced risk of heart disease
Reduced risk of hypertension
Reduced risk of diabetes
Reduced risk of bowel disease
Promotion of healthy body weight
Sources of fiber

18. Characteristics, Sources, and Health Effects of Fibers

19. Fiber Composition of Common Foods

20. 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

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

22. 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

23. Diverticula

24. 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

25. 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

26. Usefulness of Carbohydrates

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

28. A Wheat Plant and a Single Kernel of Wheat

29. 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

30. Nutrients in Whole-Grain, Enriched White, and Unenriched White Breads

31. Bread Labels Compared

32. 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

33. From Carbohydrates to Glucose – Digestion & Absorption
Sugars
Split to yield free monosaccharides
Enzymes on small intestine lining
Travel to the liver
Fiber
Fermented by bacteria in the colon
Odorous gas
Gradually increase fiber intakes

34. How Carbohydrate in Food Becomes Glucose in the Body

35. 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

36. 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

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

38. 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

39. 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

40. 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

41. 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

42. Glycemic Index of Selected Foods

43. 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

44. Prevalence of Diabetes Among Adults in the United States

45. Warning Signs of Diabetes

46. Type 1 Diabetes 5 to 10 percent of cases Common age of occurrence
Autoimmune disorder
Own immune system attacks pancreas
Lose ability to produce insulin
External sources of insulin
Fast-acting and long-acting forms

47. Type 2 Diabetes Predominant type of diabetes
Lose sensitivity to insulin
Obesity underlies many cases
Other factors foreshadowing development
Middle age and physical inactivity
Body fat accumulation
Genetic inheritance
Prevention

48. Type 1 and 2 Diabetes Compared

49. An Obesity-Diabetes Cycle

50. Management of Diabetes
Controlling blood glucose is key
Monitoring blood glucose levels
Taking medications
Control body fatness
Establish good eating patterns

51. Management of Diabetes
Nutrition
Goal: blood glucose levels in normal range
Control carbohydrate intake
Amount rather than source seems to matter
Carbohydrate recommendations
Varies with glucose tolerance
Exchange system

52. Management of Diabetes
Nutrition
Carbohydrate timing
Evenly spaced
Sugar alcohols
Advantages
Artificial sweeteners
Weight control

53. Management of Diabetes
Physical activity
Benefits of regular activity
Type 2 diabetes vs. type 1 diabetes

54. Hypoglycemia Rare, but true disease Postprandial hypoglycemia
Abnormally low blood glucose
Postprandial hypoglycemia
Requires test to detect
Fasting hypoglycemia
Symptoms
Methods to reduce symptoms

55. Finding Carbohydrates in Foods
Fruits
Vary in water, fiber, & sugar concentrations
Juice
Vegetables
Breads, grains, cereals, rice, & pasta
Brown color does not equal whole grain
Low-fat and low-sugar choices

56. Finding Carbohydrates in Foods
Meat, poultry, fish, dry beans, eggs, & nuts
Nuts and legumes
Milk, cheese, & yogurt
High-quality protein
Oils, solid fats, & added sugars
Naturally occurring vs. added sugars
Honey

57. Finding Carbohydrates in Foods
The nature of sugar
Teaspoon values
High-fructose corn syrup
Concentrated juice sweeteners
Ways to magnify sweetness without calories

58. Are Carbohydrates “Bad” for Health
Controversy 4

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

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

61. Daily Energy Intake Over Time

62. Accusation 2: Carbohydrates Cause Diabetes
Obesity and diabetes
Refined carbohydrates and diabetes
Native Americans
Glycemic load and diabetes
Whole foods

63. Accusation 3: Added Sugars Cause Obesity and Illness
Current trends
Daily
Per year
Relationship with disease

64. Added Sugars: Average U. S
Added Sugars: Average U.S. Supply per Person Compared with USDA Prudent Upper Intake Limits

65. 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

66. 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

67. Accusation 5: Blood Insulin Is To Blame
Presence of insulin
Body tends to store energy
Claims made about insulin
Expert standing on insulin
Insulin does not cause accumulation of excess body fat