Digestive System and Nutrition Quiz

Study Notes

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.

Description

Test your knowledge on the digestive system and nutrition with this quiz covering topics such as diseases affecting the small intestine, enzymes, fiber in the diet, carbohydrate sources, and their relationship to overall health.