Digestive System and Nutrition Quiz

Carbohydrate Metabolism and Exercise

• Fructose is absorbed more slowly than glucose, leading to a blunted insulin response and a more stable blood sugar.
• Large amounts of fructose may cause diarrhea.

Carbohydrate Intake and Exercise

• Carbohydrate intake helps maintain blood glucose during exercise.
• It reduces ratings of perceived exertion.
• It provides energy to muscles.
• It increases carbohydrate oxidation.
• It delays fatigue.

Muscle Glycogen and Fatigue

• Low muscle glycogen is related to the development of fatigue during aerobic exercise.
• Muscle glycogen is the primary fuel for endurance athletes, such as marathon runners.

Lactic Acid Production and Fatigue

• Lactic acid production is associated with high-intensity anaerobic exercise.

Hormones and Blood Glucose Levels during Exercise

• Epinephrine stimulates the liver to release glucose.
• Glucagon facilitates gluconeogenesis.
• Cortisol facilitates the breakdown and release of amino acids in muscle tissue.

Insulin and Blood Glucose Levels during Exercise

• Insulin levels normally drop during exercise to help maintain normal serum glucose.
• Exercise may increase sensitivity to insulin, allowing more glucose to be transported into muscle for the same level of insulin.

Hypoglycemia and Liver Glycogen

• Depletion of liver glycogen eventually leads to hypoglycemia (45 mg/100ml).
• Symptoms of hypoglycemia include feelings of dizziness, weakness, and fatigue.

Carbohydrate as an Energy Source

• Carbohydrate is an important energy source for exercise, especially in high-intensity anaerobic events and high-intensity aerobic events lasting over an hour.
• Carbohydrates can be used more efficiently when exercising in the heat and at high altitudes.

Glycogen and Gluconeogenesis

• Gluconeogenesis is the conversion of glycerol to glucose.
• Consuming foods with a lower glycemic index can lead to more stable blood sugars.

Dietary Fiber

• Dietary fiber is found in whole grains and contains nondigestible fiber, such as gum and cellulose.
• Functional fiber can be isolated or extracted from foods or manufactured synthetically.

Liver Glycogen and Aerobic Exercise

• After about 1 hour of aerobic exercise, the body utilizes about half of liver glycogen, which can hold about 75-100 g of glycogen.

Celiac Disease and Lactose Intolerance

• Celiac disease is a disease that causes damage to the lining of the small intestine.
• People with lactose intolerance have low levels of lactase enzyme, which can cause gastrointestinal distress.

High Fiber Diet

• A high fiber diet can reduce the risk of coronary heart disease, treat or prevent diabetes, and prevent colon cancer.
• Whole grain products are a good source of carbohydrates.

Periodontal Infection and Systemic Diseases

• A diet higher in sugars and starches is related to periodontal infection and various systemic diseases, such as heart disease, stroke, and diabetes.

Good and Bad Carbohydrates

• Good carbs include whole grains, making half of all grains whole grains, and total fiber.
• Bad carbs include added sugars and refined carbohydrates.

Carb Loading and Exercise

• Carb loading enhances performance in prolonged, intermittent, high-intensity exercise tasks and prolonged aerobic endurance exercise tasks.
• Athletes who benefit from carb loading include those who sustain high levels of continuous energy expenditure for prolonged periods, such as long-distance runners, swimmers, bicyclists, triathletes, and cross-country skiers.

Carbohydrate Replenishment after Exercise

• Rapid restoration of muscle glycogen is important after prolonged exercise.
• Low-GI foods may help maintain a higher blood glucose level.