“A major difference from other studies is that we advised a period of dietary weight loss with no increase in physical activity, but during the long-term follow up increased daily activity is important. Bariatric surgery can achieve remission of diabetes in about three-quarters of people, but it is more expensive and risky, and is only available to a small number of patients.”
The extent of weight loss required to reverse type 2 diabetes is much greater than conventionally advised. A clear distinction must be made between weight loss that improves glucose control but leaves blood glucose levels abnormal and weight loss of sufficient degree to normalize pancreatic function. The Belfast diet study provides an example of moderate weight loss leading to reasonably controlled, yet persistent diabetes. This study showed that a mean weight loss of 11 kg decreased fasting blood glucose levels from 10.4 to 7.0 mmol/L but that this abnormal level presaged the all-too-familiar deterioration of control (87).
Normally, blood glucose levels are tightly controlled by insulin, a hormone produced by the pancreas. Insulin lowers the blood glucose level. When the blood glucose elevates (for example, after eating food), insulin is released from the pancreas. This release of insulin promotes the uptake of glucose into body cells. In patients with diabetes, the absence of insufficient production of or lack of response to insulin causes hyperglycemia. Diabetes is a chronic medical condition, meaning that although it can be controlled, it lasts a lifetime.