A Answers (1)
National Academy of Sports Medicine answered"Your doctor or health professional should let you know if they want you to fast for a specific test. Some examples of tests that require fasting include blood lipid profile, fasting glucose, and resting energy expenditure. o Blood lipid profile evaluates your cholesterol levels, including total cholesterol, LDL (bad) cholesterol, HDL (good) cholesterol, and possibly even triglycerides (the amount of fat in your bloodstream). Eating before this test will certainly raise these numbers. o Fasting glucose is the amount of glucose (sugar) in your blood stream. Once we eat, our body should be working to either utilize or store the glucose so that there are minimal amounts in the bloodstream. Having high amounts of glucose in the blood after many hours of not eating would lead to concerns for insulin sensitivity and diabetes. o Resting energy expenditure measures your metabolism (how many calories you burn) at rest. This test requires fasting so that the body is not in the middle of breaking down and utilizing the energy from foods (this would increase metabolism beyond rested levels). "