Some sites award cash for shedding pounds, while others offer programs through which dieters lose money for not losing weight.
Fritz opted for the latter, joining StickK, where users set a goal and have to forfeit a preset amount of money if they don't reach it. The lost money goes to a user-designated friend or foe. Some choose charities, others "anti-charities": Fritz, who dislikes guns, gave herself 12 weeks to lose 1.2 pounds per week or else StickK would send $10 of her money to the National Rifle Association.
"There was one week where I didn't meet my goal. I wasn't pleased, but it made me stick to my plan more the other weeks," she says.
Fritz lost 10 pounds and has kept them off by giving herself incentives to eat healthfully.
"If you do it right, it works. The psychology behind it is sound."
According to a 2008 study published in the Journal of the American Medical Association, those who had a financial incentive to lose weight were almost five times more likely to reach their target than dieters who had no money at stake.
Sam Espinosa, StickK's director of marketing, says that 70 percent of those who have put money on the line through StickK reached their intended goal. The financial incentive, he explains, puts the goal in perspective.
"You might want to stop and get a $5 cheeseburger, but if you know that it may make you gain weight and lose $50 at the weigh-in the next day, it becomes a $55 cheeseburger," he says. "Would you really eat a $55 cheeseburger?"
That logic worked for Jacob Kosoff, an assistant vice president in the risk management department at PNC Bank, who set a goal of losing 20 pounds in 40 weeks through StickK last year. He says that he avoided donating to his anti-charity, a pro-life organization, by studying numbers.
