In today's economy, people are holding on to their money a little tighter. Which might be why wagering on weight loss -- or betting money that you can reach your weight loss goal -- is becoming more popular than ever. After all, if you can't afford to lose your money, then (after placing a bet) you darn well better lose the weight.

Recent studies suggest that people really are motivated by money to lose weight. Websites are popping up all over the web to support this trend. At StickK.com, you can bet a certain amount of money against yourself. If you fail, the money goes to the charity of your choice ... and you can even pick one that you hate.

Other sites like FatBet.com don't actually handle the money, but they offer a place for dieters to keep track of each other's progress. The trend seems to be especially popular among co-workers, and even more so among men.

Is this a healthy way to tackle weight loss? It's an instant motivator, that's for sure, and might get you through the first month. But diet and fitness are life-long goals. Unless you're going to be betting for the rest of your life, I think it's important to find some more internal motivations for eating right and breaking a sweat.

Better, I think, to find a fitness friend who will support you, not bet against you. What do you think? Would you wager on weight loss?