Drinking milk before going to bed at night can exert the best effect. From the perspective of modern nutrition, the best time to drink milk is before going to bed at night. Medical chronograph tests show that the concentration of growth hormone in human plasma will reach its peak after deep sleep at night 1 hour, when the human body is often in a hypocalcemia state. In order to supplement blood calcium, the body should adjust the nutrition in the body and transfer some calcium from bones into the blood. In the long run, bones will become loose due to calcium deficiency, especially in the elderly. If you drink milk at night, you can supplement the demand for calcium in the second half of the night and avoid the loss of calcium in your bones. In addition, there is a biochemical substance in milk that makes people sleepy-L-tryptophan, and a substance similar to morphine has sedative effect, so milk has hypnotic and sedative effects. If you drink milk half an hour before going to bed, it will help you sleep. According to the research of foreign medical scientists, drinking fresh milk before going to bed can effectively prevent the formation of gallstones. Its principle is that milk can stimulate gallbladder emptying, making it difficult for bile to accumulate and concentrate in gallbladder, thus avoiding the formation of small crystals in gallbladder and preventing gallstones.