The reason why diabetic patients do not lose weight is that it may be related to exercise and dietary factors, insulin resistance or other diseases, so it is recommended to improve the relevant examinations. 1. Exercise and dietary factors: If patients do not adhere to the principle of regular and quantitative diet, eat too many calories or eat too much high-fat food, it is very easy to lead to persistent weight loss or even increase. It is recommended that diabetic patients adhere to a low-fat, low-sugar, low-salt diet, balanced nutrition, small meals. At the same time, adhere to appropriate exercise to reduce weight. 2. Insulin resistance: many patients with diabetes have insulin resistance and hyperinsulinemia in the body, which leads to continuous weight gain, and can be treated accordingly under the guidance of doctors. 3. Combination of other diseases: When combined with other endocrine diseases, such as cortisolism, polycystic ovary syndrome, or long-term use of glucocorticoids in large quantities, can lead to persistent weight loss. When patients with diabetes mellitus have persistent weight loss, it is recommended that they consult a doctor in a timely manner to improve the relevant examinations, find the cause and treat the symptoms.