The use of bariatric surgery in obesity when compared with usual care does not appear to be associated with a reduction in mortality, a study of predominantly middle-aged male patients has found. A retrospective, cohort study of bariatric surgery programmes in American medical centres from January 2000 to December 2006 was carried out. The population studied comprised 850 patients, 74% male and 78% white, with a mean age of 49.5 years and a mean BMI of 47.4 undergoing Roux-en-Y gastric bypass. Dr Peter Savill comments on the paper: 'Bariatric surgery is an accepted intervention to reduce weight and therefore mortality in morbidly obese patients. It is currently subject to much scrutiny in our cash-deprived health service. This study suggests that it may not be as effective in reducing mortality as we believe. In summary, this study has not shown a mortality benefit of gastric bypass bariatric surgery although this cannot be ruled out in the longer term. It also does not consider the improvements in quality of life and comorbidities associated with the weight loss seen following such procedures.'