Patients who have Type 2 diabetes and undergo bariatric surgery can often see a very significant drop in the blood sugar levels that doctors long believed was due to the operation. However, new research suggests that it is actually the very low-calorie diets patients are required to follow after bariatric surgery that lead to the improvements in diabetes.


For years, it has not been known whether it was the bariatric surgery or the change in diet that causes the diabetes to improve so rapidly after the surgery. But the results of this new surgery seem to show that the reduction of patients’ calorie intake following bariatric surgery is what leads to the major improvements in diabetes, and not the surgery itself.


The study looked at ten patients who were treated only with the standard low-calorie diet given to patients after bariatric surgery. The researchers measured the effects on blood glucose levels. Then, several months later, the patients underwent gastric bypass bariatric surgery and followed the same diet and were again tested for their blood glucose levels. The patients received less than 2,000 calories per day, which is the customary diet after gastric bypass surgery.


Fasting blood glucose levels dropped around 21 per cent on average during the diet-only phase, and 12 per cent with the surgery-diet combination. After a standard meal the patients’ blood glucose levels decreased by about 15 per cent in the diet-only phase and then 18 per cent after surgery-plus-diet. The authors of the study said the results demonstrate that the extremely restrictive diet imposed after bariatric surgery is responsible for the rapid diabetes remission, which occurs within days of the procedure.



What’s Better for Diabetes – Surgery or Dieting?