Insulin is a hypoglycemic hormone and the only one in the body that lowers blood sugar. Insulin is also a pro-synthetic hormone that promotes the synthesis of protein, fat and glycogen. When insulin action is relatively or absolutely insufficient for various reasons, abnormal glucose metabolism occurs, resulting in elevated blood glucose. In patients with severe elevated blood glucose, a large amount of glucose is excreted in the urine, and the body carries out lipolysis for energy supply, and patients will experience thirst, overeating, and weight loss. After the use of insulin, the patient’s weight will increase, the possible reasons include the following: 1. blood sugar is controlled, patients with high blood sugar will show symptoms of overeating and wasting, after the blood sugar is controlled the carbohydrates eaten can be fully utilized, if the amount of food is not reduced, weight gain will occur. 2. the role of insulin, insulin can promote the synthesis of glycogen, protein and fat, the use of 3, diet, exercise factors, diabetes diet, exercise treatment should be throughout the diabetes treatment, especially when the blood sugar is controlled, if not reduce the amount of diet will appear weight gain.