In the dietary structure, diabetic patients should be polysaccharide (i.e. starchy food) as the main source of energy (55% to 60% of total calories), but can not eat too much, otherwise it is easy to cause excess calories in the body, part of which will be converted into fat, leading to overweight and obesity, and obesity is an important risk factor for the occurrence of diabetes. In addition, because diabetics have a reduced ability to regulate blood sugar, and simple sugars such as monosaccharides and disaccharides are absorbed faster in the intestinal tract, which can easily lead to a significant increase in postprandial blood sugar after eating, so diabetics are better off eating less sweets. As for fruits, diabetic patients do not have to reject all, but what fruits to eat, what time to eat, how much to eat, depending on the condition of each patient. It is worth noting that effective weight loss can prevent the onset of diabetes or significantly reduce the degree of diabetes. For now, bariatric surgery is the only way to obtain long-term and stable weight loss in moderately to severely obese people, achieving the goal of complete remission and long-term remission of diabetes. Gastric bypass surgery is the “gold standard” in bariatric surgery for the treatment of type 2 diabetes.