Bariatric surgery

Obesity is a progressive disease that shortens life expectancy and is associated with a wide range of medical problems ranging from diabetes and heart disease through to infertility and cancer. Losing weight can significantly improve or cure these conditions and helps to reduce the chances of future health problems developing. Anti-obesity drugs result in a 10% fall in body weight, but this degree of weight loss has never been shown to confer significant clinical benefit in patients with a body mass index exceeding 40 kg/m2, for whom bariatric surgery is indicated. Gastric banding is less effective than other procedures and it takes longer for target weight loss to be reached, but it is the safest,quickest and least expensive bariatric procedure. Gastric bypass is a more effective option, as weight loss is more rapid and is generally complete within a year. However, the drawback is that the bypass carries more risk. It also induces a mild degree of malabsorption, and affects satiety signalling between the gut and brain. The duodenal switch (DS) shares some features with the gastric bypass in that both operations prevent calorie absorption, although this effect is much more marked after a DS. The advantage of this approach is that excellent, reliable weight loss can be achieved without the need to reduce the stomach (and thus portion) size dramatically. However, patients need to adhere to a strict high-protein diet with vitamin supplementation if nutritional problems are to be avoided.