According to the United States and Britain, medical experts found that milk contains two kinds of past people unknown hypnotic substances, one of which is able to promote sleep to serotonin synthesis of tryptophan, due to its role, often only a cup of milk can make people fall asleep; another is similar to anesthesia sedation effect of natural morphine-like substances. Therefore, if you drink milk in the morning, it will inevitably inhibit the human cerebral cortex, affecting the daytime work and study. In addition, drinking milk in the morning is not conducive to digestion and absorption, this is because the milk protein through the stomach and the small intestine after the decomposition of amino acids can be absorbed by the body, and the morning fasting state, the stomach, intestinal emptying is very fast, so the milk can not be digested in time to be discharged to the large intestine. In addition, the protein absorbed in the food only on the basis of sufficient calories to form part of the human body tissue, if the calories are insufficient, the protein absorbed quickly into the calories and was consumed, which is undoubtedly a waste of a great deal of effort.