Blood sampling for various biochemical tests such as liver function, kidney function, blood glucose, lipids, etc. requires fasting, and generally no food should be consumed 8-12 hours prior to blood sampling. Some clinical tests require fasting because the concentration of blood becomes greater after eating and may affect the test results. However, not all tests require fasting. For example, fasting for blood glucose testing usually requires 8-12 hours of fasting. For liver function tests, avoiding high-fat and high-protein foods for 2-3 days prior to the blood draw is required, and no alcohol should be consumed within 24 hours. Therefore, it is usually recommended to eat normally, avoid alcohol, and choose easily digestible foods 1 night before the blood test, and to take blood before 9:00 am on the day of the blood draw to avoid affecting the test results. Patients are advised to develop good dietary habits, to eat as light and easy to digest as possible, to avoid overeating, and to avoid smoking, alcohol, strong tea, coffee, carbonated beverages, etc.