While bariatric surgery’s primary goal is to aid in weight loss and treat obesity, a growing body of evidence suggests that it may also be an effective treatment for Type 2 diabetes as well. A new review written by a team of researchers led by Dr. David Cummings, an endocrinologist at the University of Washington, sets out guidelines about obesity surgery as a viable treatment option for diabetes.

“We do not claim that surgery should be the first-line therapy,” Cummings said, according to the AP. But because standard care in the past consisting of diet and exercise doesn’t always work, “it’s time for something new.” The guidelines, published in the journal Diabetes Care on Tuesday, were endorsed by the American Diabetes Association, the International Diabetes Federation, and 43 other health organizations, suggesting that making the treatment more routine is well supported by the medical world.

The guidelines reviewed 11 studies that followed diabetes patients as they either received bariatric surgery or standard care of diet and exercise. The researchers concluded that surgery was actually a pretty effective way to reduce diabetes symptoms. Previously, doctors had placed surgery as a last-resort option mainly with the goal of helping people eat less and lose weight. But now, people who have a BMI of 40 or more — or for those with a BMI over 35 whose diabetes isn’t helped by lifestyle changes — should be given bariatric surgery as an option and recommendation by physicians, the authors argue.

When performed for diabetes, bariatric surgery is referred to as metabolic surgery. One 2011 study found that metabolic surgery had a tendency to cure patients’ diabetes quickly — often within days after the surgery — and well before any weight loss occurred. A more recent study found that metabolic surgery was actually far more effective in treating diabetes than typical diet and exercise, and another study showed that it helped alleviate pain and improve patients’ mobility as an added bonus. Doctors aren’t completely sure why this works; they assume it has something to do with changes in hormones, gut bacteria, and other gastrointestinal elements that impact insulin and blood sugar after surgery. That's something that simple exercise and diet can't do immediately.

“[O]ur trial… demonstrate[s] that commonly used bariatric/metabolic operations (RYGB, sleeve gastrectomy, and gastric banding) are all more effective than a variety of medical and/or lifestyle interventions to promote weight loss, diabetes remission, glycaemic control… for at least 1–3 years,” the authors write in the conclusion.

Source: Source: Cummings D, Arterburn D, Westbrook E, Kuzma J, Stewart S, Chan C. Gastric bypass surgery vs intensive lifestyle and medical intervention for type 2 diabetes: the CROSSROADS randomised controlled trial. Diabetologia, 2016.