Bariatric surgery is the most effective and long-lasting weight loss treatment for people who are severely obese and have a combination of obesity-related diseases, also known as bariatric surgery. Because of the advantages of reduced postoperative pain, fewer surgical complications and shorter hospital stays, laparoscopic bariatric surgery has become the current standard for weight loss surgery and is already the most commonly performed gastrointestinal surgery in the United States, with approximately 80,000 procedures performed each year. More importantly, weight loss surgery can treat type II diabetes, with one group reporting that 73% of patients with type II diabetes were cured after gastric banding combined with medication. Weight loss surgery can be divided into two types according to the principle, one is the type that restricts eating and the other is the type that restricts absorption. The former is mainly done by reducing the amount of food needed to achieve satiety. An adjustable band is placed laparoscopically around the upper part of the stomach, dividing it into two parts and creating a “new stomach”. The patient will feel fuller when eating and will consume less food to achieve weight loss. The most important feature of this procedure is that it does not destroy the structure of the stomach and the tightness can be changed according to the patient’s needs. It can be inserted through laparoscopic surgery with fewer complications, less pain and quicker recovery, and a short hospital stay of two to three days. However, patients often experience severe discomfort when eating after surgery, and need long-term follow-up and adjustment of the gastric band, with poor long-term results, and some patients have the band dislodged or need to be removed. This procedure is more commonly used in the southern region of China. There are various procedures for the absorption-limiting type, such as gastric reduction, gastrointestinal diversion, biliopancreatic bypass, and duodenal diversion. Gastric reduction surgery: The sleeve-shaped part of the stomach is removed in a longitudinal way to keep a small tubular stomach, thus limiting the amount of food to achieve the best weight loss effect, but there are risks of gastric leakage and abdominal infection. The patient’s postoperative comfort is good and the weight loss effect is similar to that of gastric bypass surgery, which can be said to be a very suitable weight loss surgery for Asian people, and it can improve type II diabetes, hypertension, high cholesterol and obstructive sleep apnea. The second is gastrointestinal rerouting, which is the removal of most of the stomach and a gastrojejunostomy to achieve a smaller amount of food and poorer absorption. Advantages: good weight loss, fast, more weight loss, and significant improvement in quality of life. Disadvantages: The surgery is more complicated, complications are about 1%, sequelae are high, and about one third of patients will have anemia and vitamin deficiency. Another type of surgery is biliopancreatic bypass and duodenal diversion, which is more complicated, based on gastric sleeve resection, the stomach and ileum are anastomosed, and the biliopancreatic fluid is separately diverted to the colon, so that fat cannot be absorbed.