The duration of gastric bypass surgery for diabetes is related to the postoperative dietary modifications and to whether the surgery is properly planned. If the patient cooperates with the surgery and the surgery plan is reasonable, it is usually possible to achieve long-term relief of diabetes mellitus. 1. Postoperative dietary adjustments: After gastric bypass surgery, the gastrointestinal environment of the patient has changed, and it takes at least half a year of dietary adjustments after the surgery. Patients should regulate their diets under the guidance of their physicians and health care providers, which will play a fundamental role in guaranteeing long-term remission of diabetes mellitus. 2. Whether the surgical plan is reasonable or not: the formulation of the pre-operative surgical plan varies from person to person, and it is very much related to the experience of the surgeon in charge. Whether the surgical plan is reasonable or not is also closely related to the duration of diabetes maintenance and dietary adjustments after surgery. Therefore, the duration of diabetes after gastric bypass surgery depends on many factors, and it is recommended that the patient should follow a standardized diet under the guidance of the physician and dietitian, and undergo regular follow-ups.