The surgery, which includes a range of procedures that are collectively known as bariatric surgery, is often a last-resort option for people who are seriously overweight, and with a body-mass index in excess of 40.
Because of its relative success in helping people lose weight, more and more people have been choosing it, even though the surgery is still seen as controversial and, in the US, many health insurers will not pay for it.
It also comes at a high price in terms of human life. Researchers studied the outcomes of 16,683 operations in Pennsylvania between 1995 and 2004, and discovered that 440 patients - or 2.6 per cent - died. Of these, nearly half were the result of some heart problem that occurred within the first 30 days following surgery, while it is estimated that the remainder committed suicide.
(Source: Archives of Surgery, 2007; 142: 923-8).