The Carbohydrates: Sugar, Starch, Glycogen, and Fiber Chapter 4

Carbohydrate – Mainly Glucose – Is Made by Photosynthesis

Usefulness of Carbohydrates

How Monosaccharides Join to Form Disaccharides

How Glucose Molecules Join to Form Polysaccharides

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

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

Characteristics, Sources, and Health Effects of Fibers

One Way Fiber in Food May Lower Cholesterol in the Blood

Fiber Recommendations and Intakes Few people in U.S. meet recommendations 14 grams per 1,000 calories 25 g/day for women, 38 g/day for men Too much fiber? Dangers of excess Nutrient losses

Whole Grains USDA food patterns Flour types At least half of daily grains should be whole Flour types Four parts to the kernel Germ Endosperm Bran husk

How Carbohydrate in Food Becomes Glucose in the Body

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 Nutrient consequences?

The Body’s Use of Glucose Basic carbohydrate unit used for energy Body handles glucose judiciously Storage form in body is glycogen Liver 1/3 of supply, Muscle 2/3 of supply Brain, nervous system, red blood cells

Splitting Glucose for Energy Glucose is broken in half Can reassemble Broken into smaller molecules Irreversible Two pathways Aerobic and anaerobic

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

Blood Glucose Regulation

How Is Glucose Regulated in the Body? Tissue glycogen stores Muscles, liver, brain Stores can be depleted in less than 1 day Release of glucose from glycogen Glucagon Epinephrine Gradual release of glucose Meal composition

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

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 build up and less insulin needed Nutrition concerns

Glycemic Index of Selected Foods

Diabetes Uncontrolled blood glucose Dangers of diabetes 126 mg/dL fasting Dangers of diabetes A leading cause of death in US Toxic effects of excess glucose Inflammation: eyes, kidney, heart Damage blood vessels and nerves Loss of circulation and nerve damage

Prevalence of Diabetes among Adults in the United States

Warning Signs of Diabetes

Type 1 and Type 2 Diabetes Compared

An Obesity-Type 2 Diabetes Cycle

Management of Diabetes Primary goal Keep blood glucose level in normal range Proper diet Control amount of carbohydrate more than type Regular meals (several small meals) Exercise Glucose monitoring Medication Weight loss by those who are overweight 5-7 percent

Hypoglycemia Rare, but true disease Abnormally low blood glucose Symptoms: anxiety, rapid heartbeat, and sweating Causes Poorly managed diabetes Medications Alcohol abuse Others

Finding Carbohydrates in Foods Fruits Vary in water, fiber, & sugar concentrations Juice Vegetables Grains Low-fat and low-sugar choices

Finding Carbohydrates in Foods Protein foods Nuts and legumes Milk and milk products High-quality protein Oils, solid fats, & added sugars Naturally occurring vs. added sugars Honey