There has been a 785 per cent rise in weight-loss surgery over five years, NHS figures have shown.
Data compiled by the NHS Information Centre revealed a rapid rise in the number of operations carried out for the most obese people in England.
Data for 2003/04 showed there were 480 procedures, rising to 4,246 in 2008/09. Of operations carried out in 2008/09, 42 involved removing part or all of the stomach.
Another 1,378 included fitting a gastric band to make the stomach smaller, 504 were for stomach stapling and 2,210 involved a gastric bypass. Some 124 operations involved inserting a "bubble" in the stomach to fill it up.
The NHS Information Centre says its data is the most reliable available for the total number of operations carried out on the NHS.
The National Institute for Health and Clinical Excellence recommends the surgery only for the morbidly obese (body mass index of 40 or more, or 35 if there is another existing condition which could improve with surgery, such as diabetes). But people must have failed on other methods, such as traditional diets, first.
Tam Fry, from the National Obesity Forum, said: "These figures just show how bad things have got with the obesity epidemic. We have alternative ways of losing weight but when people realise this is a possibility, they could go for it.
"Worse still, there is a premise that if you feed yourself up you get to the bar - 35 BMI with co-morbidities or 40 without - then the operation would be yours.
"Those patients will be demanding this on the NHS, and a lot of doctors will think if it's preventing years of diabetes, cardiovascular conditions or other ill health, then it's worth it. It takes an age for a patient to slim down, but one flick of the surgeon's knife will address the problem."