But Sears’ experience highlights what dieters and doctors alike say is a growing dilemma. Spurred by strict insurance policies that limit surgery to high BMIs of 35 or 40, some obese people are actually striving to gain weight — in order to lose it.

Web sites devoted to weight-loss surgery are full of advice and anecdotes from would-be losers who claim they ate piles of bananas, chowed down on burgers and curly fries or swilled gallons of water to nudge the scale to the correct heights.

“That happens all the time,” said Dr. Robert Michaelson of Northwest Weight Loss Surgery in Everett, Wash., who was a clinical investigator for the FDA trial. “I’ve seen people come in with ankle weights on.”