Dieters do better when bribed, study shows

Willpower apparently can be bought. The chance to win or lose $20 a month enticed dieters in a yearlong study to drop an average of 9 pounds — four times more weight than others who were not offered dough to pass up the doughnuts.

Many employers, insurers and Internet programs dangle dollars to try to change bad habits such as smoking or not exercising, but most studies have found this doesn’t work very well or for very long.

The new study, done with Mayo Clinic employees, was the longest test yet of financial incentives for weight loss. Doctors think it succeeded because it had a mix of carrots and sticks — penalties for not losing weight, multiple ways to earn cash for succeeding, and a chance to recoup lost money if you fell off the “diet wagon” and later repented.

Incentives are “not like training wheels where people learn healthy habits and then will continue them on their own” — you have to keep them up for them to work, said one study leader, Dr. Steve Driver of Mayo in Rochester, Minn.

And if you’re looking to set up a system like this at work or among friends, the key is to make it self-sustaining, Driver said. The Mayo one did that by having people who didn’t lose weight put penalties into a fund that paid rewards to those who did.

It’s also a good idea to make people pony up in advance. One woman flew into a tizzy when she stepped on a scale at a weigh-in and was told she’d have to pay.

“She headed for the door” but later came back and paid, Driver said. “People in Minnesota are pretty honest.”

Driver will discuss the study this weekend at an American College of Cardiology conference in San Francisco. The group released results Thursday. Mayo paid for the study and Driver owns stock in Gympact, a company with an Internet program that gives financial incentives for exercising.

The diet study involved 100 obese employees at Mayo Clinic but was not a workplace wellness program. Half were given weight-loss counseling, monthly weigh-ins and a three-month gym membership. The others had those things plus financial incentives.