Bariatric surgery is a key step in helping obese patients to lose weight successfully and is the threshold of health for obese patients. In addition to this, post-operative lifestyle changes are a very important process to ensure the efficacy of the surgery. It has been reported that approximately 20-30% of obese patients regain weight after bariatric surgery due to lack of attention to healthy lifestyle maintenance. After weight loss and diabetes surgery, doctors and case managers (nurses) will give a series of explanations to post-operative patients; including post-operative diet, how to follow up, etc. In the post-operative diet, they will repeatedly explain that they should chew slowly and swallow carefully when eating, which may be difficult to accept among many obese patients, because most obese patients tend to eat faster before surgery, and they describe themselves as eating not in eating but in pouring rice into their stomachs. They describe themselves as not eating but pouring food into their stomachs, and a meal is solved in a few minutes. Once you have had bariatric surgery, such eating is very dangerous; you must learn to chew slowly and swallow carefully, and it is a scientific requirement to chew each bite 28 times before swallowing. Why is this? First of all, one of the basic principles of bariatric surgery, whether it is the eliminated gastric banding or the current classical gastric sleeve resection or gastric bypass, is the reduction of the volume of the stomach, which requires a residual gastric volume of no more than 100 ml, usually 70-80 ml, and a residual gastric volume of 20-30 ml for gastric bypass. –Even on the second day after the surgery, the doctor allowed to eat clear liquid – water, but also small mouth and slow swallowing, 20ml each time, many times to drink, at this time, large mouth to drink, not only will cause reflux, choking feeling, serious may burst the residual stomach, leading to the residual stomach rupture or gastrointestinal anastomosis rupture of serious complications, so that a surgery should be 3 to 5 days after the surgery can be discharged from the hospital incalculable disaster. Secondly, even if the bariatric surgery is safely discharged from the hospital, the doctor agrees that solid food can be eaten. The beginning period, usually 1-2 months, is to eat little and often. Although solid food stays in the remnant stomach for significantly less time than fluid food, its emptying time is still significantly faster than before surgery, in sleeve gastrectomy patients whose postoperative intragastric pressure is increased, and in gastric bypass patients whose pylorus is absent, which is the pathological and anatomical basis for the fast-time emptying of food in the stomach. In all patients with major gastrectomy there is a postoperative complication – dumping syndrome. Its clinical manifestations are palpitations, tachycardia, sweating, weakness, and pallor half an hour after the patient has eaten, and in severe cases, there may be gastrointestinal symptoms such as nausea, vomiting, abdominal cramps, and diarrhea. The occurrence of these clinical symptoms is related to the secretion of large amounts of intestine-derived vasoactive substances by the endocrine cells of the intestine due to the entry of large amounts of hyperosmolar food into the intestine. These clinical problems can also occur in patients undergoing bariatric surgery because the genesis of bariatric surgery is major gastric surgery. It is believed that eating too fast may cause excitement of the hunger center and lead to eating more food, thus causing obesity. Slow chewing satisfies the pleasure of eating and suppresses the excitement of the hunger center, and in the long run, the appetite of obese people decreases, the intake of energy decreases, and the storage of fat decreases, thus achieving a long-term cure. Therefore, changing eating habits after bariatric surgery, chewing and swallowing slowly when eating is not only the key to maintaining the efficacy of bariatric surgery, but also preventing eating discomfort and possible complications after surgery. Slow chewing and swallowing allows obese patients to not only be lean and healthy after surgery, but also to become more gentlemanly in their eating behavior.