Drinking milk on an empty stomach is unscientific and undesirable. As water occupies a large proportion in milk, drinking more milk on an empty stomach dilutes the gastric juices, which is not conducive to the digestion and absorption of food. Fasting, intestinal peristalsis is very fast, milk in the gastrointestinal tract through the time is very fast, the retention time is very short, nutrients are often too late to be absorbed, rushed into the large intestine was excreted. Milk is rich in high-quality protein, the main components of these proteins are the main nutrients that make up the human body and have a repairing effect on the tissues. If you drink milk on an empty stomach, not only will the milk be expelled from the stomach quickly, but the valuable proteins mentioned above will also be decomposed by the body and consumed as calories, which will not fully play the role that protein should play. If you drink milk on an empty stomach, the protein in the milk will be converted into sugar and protein energy due to the lack of sugar and fatty food supply, so it is not advisable to drink milk on an empty stomach.