Randy Carlson’s lifelong battle with portion control and unhealthy food choices have earned him a big red "X" on his back: heart disease. But even carrying the label of the nation’s No. 1 cause of death wasn’t enough to motivate Carlson to make changes.

The one incentive powerful enough, however, is money.

"I enjoy taking risks, but I don’t like to lose, especially money," the 58-year-old Maple Grove, Minn., man said of his decision to use HealthyWage.com, an online weight loss program that doles out money to dieters who meet their weight loss goals.

Carlson paid $100 to join the new "10 percent Challenge," which encourages dieters to lose 10 percent of their body weight in six months. If he doesn’t, he loses his $100. But if he reaches his goal, he doubles his money and wins $200.

HealthWage also has a BMI challenge that pays up to $1,000, and a team contest in which groups of five try to win a $10,000 grand prize.

And Carlson isn’t the only person who’s motivated by cash. According to a 2008 study published in the Journal of the American Medical Association, dieters who had financial incentives to lose weight were nearly five times likelier to meet their goals than dieters who had no potential for financial reward.

So far, Carlson is on track to double his bet of losing 26.5 pounds in six months.

"I feel like I’m going to be successful," he said. "There’s just no way I’m going to lose that bet."

Dieters must have a medical professional certify their weight loss in order to win.