Cash Incentives Fail to Help Some Lose Weight, Study Says

Americans have never been fatter. Here's one reason it will be hard to turn that around: You can't even pay people to shed weight.

Out this month in the journal Applied Economics Letters is new research by Nicholas Burger and John Lynham. The study's conclusion is that even when people bet they'll lose weight -- sometimes putting down big money -- they still can't take off the pounds. A full 80 percent of overweight bettors lost their wagers. "Humans are impatient," Lynham, an economics professor at the University of Hawaii, told AOL News. "And we have impulses that go against our long-term best interests -- even when those interests include money."

Lynham and Burger looked at a London betting house, William Hill, which for the past 15 years has accepted bets from people looking to lose weight. At first the house was wary: Why take a bet from someone who can directly influence its outcome? It'd be like letting a gambler go down to the track and club the legs of every horse but the one he put money on. Except -- no, not really. Over time, William Hill noticed that few of the weight-loss bettors were winning. Plus, the bets themselves got lots of play in the British tabloids. (This is how Lynham came to the study. He grew up in Ireland and remembers those fevered stories.)

William Hill makes bettors write out why they would like to place the bet. This is the clever part. Lynham and Burger note that 55 percent of bettors describe to William Hill their struggles in losing weight; 70 percent say they're betting as a way to force themselves to slim down, because little else seems to work.