Chapter 4: Carbohydrates
Functions of carbohydrate
Supplies energy
Protein sparing
Prevent ketosis
Sweetener
Monosaccharides
Structure
Glucose
Fructose
Galactose
Disaccharides
Formed when two monosaccharides combine
Maltose (Gluc + Gluc)
Sucrose (Gluc + Fruc)
Lactose (Galactose + Gluc)
Disaccharides
(Fig. 3-2)
Complex carbohydrates
Oligosaccharides
Polysaccharides
Dietary fiber
Oligosaccharides
3-10 monosaccharides
Found in beans and legumes
Not digested
Metabolized by bacteria in the large intestine
Polysaccharides
30,000 or more monosaccharides bound together
Amylose
Glycogen
Polysaccharide: Glycogen
Dietary Fiber
Undigested plant food
Insoluble fiber
Soluble fiber
Health benefits of dietary fiber
Promotes softer, larger stool and regularity
Slows glucose absorption
Reduces blood cholesterol
Reduces heart disease
Reduces hemorrhoids and diverticula
Diverticula
(Fig. 3-7)
Recommended CHO intake
No RDA set
50-100 gm of CHO/day to prevent ketosis
Reasonable goal: 45% of total kcals from starch; 55-60% from total CHO
Recommended dietary fiber intake
20-35 gm of fiber/day (10-13 gm/1000 kcals)
Ave. U.S. intake: ~16 gm/day
Too much fiber will:
require extra intake of fluid
bind to some minerals
Recommendation for simple sugar intake
Low nutrient density
Recommend no more than 10-15% of total kcal/day
Ave. U.S. intake: 18% of total kcal/day
Added to food and beverages during processing
The rumors about sugar
Fallacy
The truth about sugar
Facts
Types of Sweeteners
Sucrose
High-fructose corn syrup
Brown sugar
Maple syrup
Honey
Sugar alcohols
Sugar substitutes
Ave. U.S. intake ~24 pounds per year per person
Does not promote tooth decay or blood glucose level
Very low calorie
Sugar substitutes
Saccharin
- 180-200x sweeter than sucrose
- Excessive intake is linked to bladder cancer in lab animals
Aspartame (NutraSweet)
Composed of phenylalanine and aspartic acid
180-200x sweeter than sucrose
Acesulfame (Sunette)
Newest sugar substitute
200x sweeter than sucrose
Other sugar substitutes
Altimane -2000x sweeter
Sucralose - 400 - 800 x sweeter
D-Tagatose- same sweetness, but half the calories
Sweetener paradox
A high-carbohydrate diet
Health benefits of a high-carbohydrate diet
Regulation of blood glucose
Fig. 4-8
Hyperglycemia
Hypoglycemia
Role of the pancreas in blood glucose control
Role of the pancreas
Release of insulin
Release of glucagon
Maintain Homeostasis
Function of Insulin
Net effect: lowers the blood glucose
Function of Glucagon
Net effect: raises blood glucose
Other hormonal influence
Epinephrine/norepinephrine
Cortisol and growth hormone
Diabetes Mellitus--Type I
Insulin dependent
Diabetes Mellitus--Type II
Non-insulin dependent to start
Consequences of uncontrolled blood glucose
Nerve damage, Heart disease, Kidney disease, Blindness, Atherosclerosis
Lactose Intolerance
Reduction in lactase
Primary and Secondary lactose intolerance disease
What you can do if you are lactose intolerance
Dental Caries
