Is gastric bypass surgery or lifestyle change better for managing type 2 diabetes?

The major treatment goal for type 2 diabetes (T2D) is control of blood glucose (sugar) levels. High blood glucose can lead over time to multiple complications, including cardiovascular (heart) disease. Lifestyle changes, such as improved diet and weight loss, are known to help with blood glucose control. Major weight loss, however, is difficult for patients to sustain over the long-term.

There is evidence that Roux-en-Y gastric bypass (RYGB) improves diabetes significantly. This surgery is usually only carried out on severely obese patients. Whether lifestyle changes or RYGB are better in improving diabetes is unclear. 

This study included mild-to-moderately obese adults with T2D. 15 patients underwent RYGB surgery. 17 patients underwent a program that included exercise, behavior-change skills, and a dietician-directed diet to aid weight loss and glucose control. Diabetes remission rates (no sign of disease) were compared after 1 year.

Compared to weight before surgery, patients in the RYGB group lost 25.8% of their bodyweight, compared to 6.4% in the lifestyle changes group. 60% of RYGB patients had no symptoms of T2D after one year, compared to 5.9% of the lifestyle changes patients. Reductions in HbA1c (average blood glucose over 3 months) levels were similar between the groups, but reductions did not require medication in the RYGB group. Patients in the lifestyle group were fitter and had more lean body mass. 

The study concluded that RYGB had a much better outcome in mild-to-moderately obese diabetics than very rigorous lifestyle changes. The authors pointed out that the current practice of deciding who gets surgery based on their body mass may need to be revised to include mild and moderately obese patients.

This was a small, fairly short study.