New research suggests that bariatric surgery significantly reduces the risk of developing type 2 diabetes.

Researchers found that bariatric surgery could reduce the risk of developing type 2 diabetes by around 80 percent in obese people, compared with standard care.

Being overweight or obese is the main modifiable risk factor for type 2 diabetes. More than 80 percent of adults with type 2 diabetes are overweight or obese. In England, just over a quarter of adults (26 percent) were classified as obese in 2010 (body mass index [BMI] 30kg/m2 or over). Up to 3 percent of people with severe obesity (BMI 40kg/m2 or more) develop diabetes each year.

"Our results suggest that bariatric surgery may be a highly effective method of preventing the onset of new diabetes in men and women with severe obesity," researcher Martin Gulliford said in a statement. "We need to understand how weight loss surgery can be used, together with interventions to increase physical activity and promote healthy eating, as part of an overall diabetes prevention strategy."

For the study, researchers used electronic health records from the UK Clinical Practice Research Datalink to assess the effect of contemporary surgical weight loss procedures on the development of diabetes.

They identified 2167 obese adults without diabetes who underwent one of three surgical procedures (laparoscopic adjustable banding, sleeve gastrectomy, or gastric bypass) for weight loss from 2002 onwards. These participants were compared with 2167 controls matched for age, sex, body mass index, and blood glucose control (measured as HbA1c) who did not have surgery or other obesity treatments. Participants were followed up for a maximum of 7 years (median 2.8 years).

During follow-up, 38 new diagnoses of diabetes among participants who had weight loss surgery were recorded, compared with 177 in control participants. Compared with controls, diabetes incidence was reduced by about 80 percent in participants who had surgery, even after controlling for other important factors including smoking, high blood pressure, and high cholesterol.

The findings are detailed in The Lancet Diabetes & Endocrinology.