Yogurt contains a large number of probiotics, such as lactobacillus, which are needed by the human body. If yogurt is consumed on an empty stomach, the level of lactobacillus in the body will rise sharply, causing disorders in the intestinal flora and accelerating intestinal peristalsis, which will lead to diarrhea. At the same time, yogurt contains lactose, and the human body needs lactase to digest lactose, so lactase secretion in the body is low in fasting state, which cannot fully digest and decompose lactose, which will cause lactose intolerance and diarrhea symptoms. Yogurt has strong health effects, such as preventing osteoporosis, lowering blood pressure, improving immunity, preventing gynecological infections and controlling appetite. However, care should be taken not to consume yogurt on an empty stomach and not to heat it when drinking it, otherwise it will destroy the lactic acid bacteria in yogurt and reduce the health effects of yogurt. Patients with diabetes, atherosclerosis, cholecystitis and pancreatitis should avoid consuming full-fat yogurt to avoid aggravating their condition.