Diabetes is a metabolic disease in which blood glucose rises due to the impaired function of insulin, the body’s main glucose breaker, so people with diabetes need to reduce their sugar intake as much as possible. In fact, there is no direct relationship between excessive sugar intake and the proven pathogenesis of diabetes. Most of the diabetes patients in China are obese people with excessive fat in the waist and abdomen, and there are also some people who appear to be not seriously obese, but the accumulation of fat in the abdomen leads to visceral fat that causes obesity associated with the disease. In general, obese people are a high risk group for type 2 diabetes. Although excessive sugar intake is not directly related to diabetes, the calorie content of sugar is relatively high, and long-term excessive consumption can easily lead to obesity, which in turn easily forms insulin resistance and affects the metabolic level of insulin, which is how obesity type 2 diabetes comes about. In the treatment of diabetes, internal medicine has been used for decades, but it can never change the disadvantage of not being able to cure the disease, and the endless drug expenses and numbing life interventions add to the problem. For this reason, gastric bypass surgery is recommended for patients with type 2 diabetes caused by obesity. The surgery realigns the body’s gastrointestinal tract and is able to limit the amount of food intake and nutrient absorption in the body, effectively reducing sugar intake and absorption. The surgery can also achieve efficient weight loss, repair damaged insulin function and allow the body to function again in breaking down sugar.