Grapes are a nutritious, sweet and sour fruit. Eating grapes in moderation can replenish nutrients and promote digestion, whether during the day or at night, and eating grapes at night can also promote sleep. But if you eat grapes inappropriately, no matter what time of day you eat, it may cause gastrointestinal discomfort, oral disease, obesity and elevated blood sugar. A. Benefits 1, supplemental nutrients: grapes are rich in fructose, the human body must be glutamic acid, arginine, tryptophan and more than a dozen amino acids, vitamin B, vitamin C, vitamin P and other vitamins, calcium, potassium, phosphorus, iron and other minerals, as well as other beneficial ingredients, can supplement the body consumption, is conducive to supplemental nutrition, relieve fatigue; 2, promote digestion: grapes contain acidic substances and dietary fiber, eaten in moderation at night can promote gastrointestinal motility, is conducive to help digestion and prevent constipation; 3, promote sleep: grapes contain melatonin, melatonin can improve sleep quality, shorten the time to fall asleep, long-term bedtime consumption is conducive to promoting sleep. Second, the bad 1, gastrointestinal discomfort: common in people with weak digestive function, eat a lot of grapes at night or eat cold grapes, in the cold and acid stimulation, may cause nausea, diarrhea, abdominal pain and other symptoms; 2, oral diseases: grapes contain acid may corrode teeth, if you do not brush your teeth on time after eating grapes, grapes in the sugar left in the teeth will become a breeding ground for oral bacteria If you do not brush your teeth regularly, the sugar left in your teeth will become a breeding ground for oral bacteria, which may cause tooth decay, pulpitis and other oral diseases; 3, obesity and elevated blood sugar: glucose contains sugar, which can produce a lot of heat and cause elevated blood sugar. If the calories are not consumed through exercise, it may lead to obesity. For diabetic patients, elevated blood sugar without timely medication may cause ketoacidosis in serious cases.