Clinically, patients with diabetes do not experience progressive weight loss if their blood sugar is smoothly controlled. Weight loss will exist before the onset of diabetes because of the loss of energy material in the body due to elevated blood glucose and loss of urine sugar. After the diagnosis of diabetes, standardized glucose-lowering treatment is needed. After the blood glucose control is stable, the patient’s metabolic disorder can be corrected and the patient’s weight can return to the standard state. However, if the patient does not have standardized glucose-lowering treatment, poor glycemic control and metabolic disorders still exist, the patient will still be at risk of progressive weight loss. Therefore, the change of weight and weight loss in diabetic patients can assess the degree of good glycemic control, and if the patient has progressive weight loss, it often indicates that the glycemic control is not up to standard.