Obesity is a major risk factor for type 2 diabetes. Worldwide, 80 per cent of people with type 2 diabetes are overweight or obese at the time of diagnosis. Diabetes is normally treated by using insulin injections and drugs to control blood sugar. However, many diabetic patients who had stomach surgery to lose weight found that their diabetes improved, even before they had lost any weight.

However, the medical profession is keen to point out that weight loss surgery is not a cure for type 2diabetes, but it can improve blood sugar control, according to a new study published in the British Journal of Surgery. Whereas some previous studies have claimed that up to 80 per cent of diabetes patients have been cured following gastric bypass surgery, researchers at Imperial College London found that only 41 per cent of patients achieve remission using more stringent criteria.