When lawyer Carol Fritz decided to add "actress" to her resume last year, one thing stood in her way: She wanted to list her weight as 148, 10 pounds lighter than she actually was.

"I like to think of myself as an honest person," the Powelton Village resident says. "I was ready to post that resume on the Internet with that number, so I needed to get there. I just needed an extra push."

That extra push for Fritz was using a financial incentive to help her reach her weight-loss goal. At a time when nearly two-thirds of Americans are overweight or obese, many people are using monetary motivation to kick-start healthy habits, and a crop of independent websites have popped up to help.

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.

"I'm an economist by training, so I'm always thinking about incentives. It helped me add a new price to things," he says. "It helps you with your day-to-day choices."

Something else that helped Kosoff was adding a social component, using his Facebook page to post photos of his weekly progress.

"People would see the posts and congratulate me. If I started putting on more weight, people would see and I'd feel worse," he explains. "Using peer pressure forces you to have more accountability."

That social accountability is the basis for DietBet, a weight-loss-wager website that launched Dec. 19. The site, which lets groups of people choose how much weight to lose and what is at stake, acts as the infrastructure, recording weight loss and holding bets for the participants.

DietBet founder Jamie Rosen says users can send messages encouraging one another and track progress through an online scoreboard.

"It becomes this fun social experience that's the opposite of what people think of dieting," he says. "It's not lonely or solitary. You see a message from someone saying 'I'm going to skip dessert' and it makes you want to skip it, too.

"Playing with people you care about and being humiliated by knowing that you didn't reach your goal is as powerful as the financial incentive," Rosen says.

While Rosen is convinced this combination works in the short run, he isn't certain about the long haul.

"I don't know about the long run," he says. "That's been a problem that no one in the weight-loss academic world has been able to figure out."

Marjorie Nolan, a national spokeswoman for the Academy of Nutrition and Dietetics, says that while wagering money can be a good way for some people to take the weight off, it isn't the best way to keep it off.

"Once the incentive of money is gone there needs to be another incentive that takes its place," she says. Instead of betting, Nolan recommends that dieters use their money to seek professional advice.

"Often the commitment clients make when paying upfront for weight-loss counseling is all the incentive they need."

If you skip your workout, this app is apt to know

If you just signed up for a gym membership, convinced that you'll go every day this year, keep in mind that you're essentially throwing money away when you don't go. If you need a little more motivation to make the trip and work out, Gym-Pact (www.gym-pact.com) is a new iOS app and webapp that lets you put your money where your mouth is. Go to the gym and check in with your phone and you'll be rewarded with cash payouts. Skip your workouts, and the service penalizes you and your bank account.

From the "habit-building by redistribution of wealth" department, Gym-Pact asks you to set the stakes when you sign up and tell the service how much money you're willing to lose if you miss your workouts, and how frequently you want to go to the gym. The service then uses your phone's GPS to make sure you're actually at the gym and not on your couch at home. If you miss too many days, the service penalizes you by charging you the amount you put on the line. The money it collects from people who don't go to the gym is distributed every week among the people who did go, meaning you're rewarded with cash if you actually work out.

Gym-Pact supports more than 40,000 gyms and fitness centers around the country, and even lets you add more - as long as it's an actual fitness center. No home gyms or office gyms allowed, likely because Gym-Pact worries that would make it too easy to game the system. Signing up may be a bit masochistic, but if you really need motivation to hit the gym, this service will give it to you.

- Alan Henry, Lifehacker.com