Britain's National Health Service could save millions of pounds a year by offering more weight-loss surgery for obese patients, a medical study said Wednesday.
Around a million people in England meet recommended criteria for so-called bariatric surgery, but only 3,600 NHS weight-loss operations were carried out last year.
Obesity and related medical conditions directly cost the NHS 4.3 billion pounds a year, while the impact on the wider economy runs into millions.
The Office of Health Economics estimates that 1.3 billion pounds would be saved within three years, if a quarter of those eligible underwent surgery.
Savings of between 35 million and 150 million pounds could also be made in welfare payments as people return to work, the study, titled "Shedding The Pounds", said.
John Black, president of the Royal College of Surgeons, which commissioned the report along with the National Obesity Forum, described the figures as "simply staggering".
"The NHS cannot afford to ignore the mounting evidence that shows that bariatric surgery, for those patients where all other treatments have failed, is not only proven to be successful but also hugely cost effective," he said.
The report was funded by health firms Allergan and Covidien, which make medical equipment used in weight-loss surgery.
Almost a quarter of adults in England were obese in 2008 -- a figure expected to double by 2050.
The National Institute for Health and Clinical Excellence (NICE) says people with a body mass index (BMI) of more than 40 -- or between 35 and 40 if they also have a condition such as diabetes or high blood pressure -- are eligible for surgery.
British health minister Paul Burstow said: "Whether to prescribe drugs or recommend surgery is rightly a clinical decision.
"Independent guidance on obesity from NICE recommends that drugs and surgery should always be a last resort -- a better diet and more exercise should be tried first."