Weight loss surgery, such as gastric bypass and Lap-Band surgery, can significantly reduce the risk for Type 2 diabetes in obese people, a new study concludes. Weight loss surgery, compared to normal care, reduced Type 2 diabetes risk in obese people by 80 percent.

The research, led by Martin Gulliford, professor of public health in the Division of Health and Social Care Research at King's College London, compared 2,167 adults with obesity who had weight loss surgery to a control group of 2,167 individuals of the same body mass index, or BMI, age, sex and blood glucose control who did not undergo obesity treatment or surgery. Type 2 diabetes is the most common type and is the result of insulin resistance. The pancreas, which controls insulin production, cannot make enough insulin to regulate glucose levels.

The researchers followed the participants up to seven years and found that 38 people in the weight loss surgery group developed Type 2 diabetes compared with 177 people in the control group. The researchers controlled for other Type 2 diabetes risk factors like smoking, high cholesterol and high blood pressure.

"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. 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," Gulliford said in a statement.

Blood glucose control tests include A1C or eAG, which determines the average level of glucose in the blood over the last two to three months. "Glucose enters your red blood cells and links up (or glycates) with molecules of hemoglobin. The more glucose in your blood, the more hemoglobin gets glycated. By measuring the percentage of A1C in the blood, you get an overview of your average blood glucose control for the past few months," the American Diabetes Association explains.

Jacques Himpens from Saint Pierre University Hospital in Brussels noted some problems with the study. The weight loss surgery group was better monitored and the study did not measure glucose metabolism, he said.

"Although the results of Booth and colleagues bring us a step closer to confirming the effect of bariatric surgery on the incidence of de-novo Type 2 diabetes, many questions still remain unanswered, and more evidence is needed to convince endocrinologists about the nature of this effect," Himpens said in a linked comment.

The study was published in the Lancet Diabetes & Endocrinology journal.