The desire to sleep after eating at night may be caused by a combination of reasons: 1, due to overworked body fatigue during the day, after eating to help digestion, blood redistribution, supplying the gastrointestinal system blood flow increased, so the cerebral artery blood supply elephant pairs reduced, brain ischemia and hypoxia will easily lead to sleepiness. 2, in the process of digestion and absorption, the vagus nerve excitability increased, sympathetic nerves are inhibited, people are also prone to 3, increased blood viscosity, this group of people after eating food digestion and absorption, will aggravate the degree of blood viscosity, slowing down the blood flow, can aggravate the situation of cerebral ischemia. 4, increased blood sugar, seen in the diabetic population, after eating insulin secretion is relatively insufficient, blood sugar rapidly increased, the human body in a state of high blood sugar love to sleep.