Transcript for Dieting Website Has Users Bet to Lose, in Order to Win
When you're a size fourteen address. On standing next to bride who looks like this can be daunting -- Fit but Christina Mari is up to the -- could really like to be. Crossed our fingers to channel those pounds Christina is quite. Literally putting her money where her mouth things I started the diet that three months ago each month she pays 385. Dollars to healthy wage. A company that allows you to place a bet that you can lose the weight. The wager if she loses forty pound six -- she'll win 5000 dollars. Plus get all her money back for a grand total of 7310. Dollars. I am now down twenty pounds which is creeks and so I have another twenty to -- -- goal in what is. But if Christina doesn't lose the weight she's out thousands of dollars I really need to get my act and -- gear so that I didn't you know. Witnessed that because I cannot afford not -- With all her money on the line this could be just the ultimate motivation to shed the pounds but can she -- it. According to studies people using money as a motivate here are five times more likely to reach their goal -- The future of dieting -- for weight loss is -- Betting on your retirement at Caesars not according to Dave's -- -- camp fitness expert and author of eight to beat people. Go on these short term weight diet crashes. And then they immediately wanna reward themselves at the end of on and they do that with a bag of -- -- Healthy -- says it's party paid out more than two million dollars in prize money. Yet only 13 of participants. Actually win their bets. In -- -- there's always a win somewhere mean that people through the number of people who make a -- and then just call off the radar buried here. Almost everyone loses some way the question is are you going to accomplish your goal. Christina is hoping she can beat the odds and actually win. Her weight has been a lifelong struggle. -- -- Being six years old and thinking that I was -- I got on us down -- spat at her heaviest she was 295. Pounds and -- tried everything. Everything that you can imagine I almost feel like -- and such an expert on losing weight it's just the actual follow through that -- you know struggled with over the years. After a promising start two months after the trip to the bridal -- Christine is only dropped eight pounds I have another twelve pounds. I need to be a 194 pounds to witness that -- -- I have a little bit more than a month. But she's fallen off the wagon a few times -- have a -- and then -- have a whole package of cookies or I would eat an entire kind of ice train so we just one month ago Christina has to kicker diet into high -- eating only 16100. Calories a day I live in the way to the Graham. Pretty much everything she opts to tracker wait on line by recording every calories she consumes and tracks every step she takes with a -- -- I have 4034. Steps right now the wait is coming off ice awareness and usher now it comes down to almost my knees. But as far as she's come. It may not be enough -- six point eight. A little bit higher than it was yesterday but it -- Christina loosen -- in time to win the bet remember more than 7000. Dollars is on the line. Two weeks later Christina is riding high. She's lost 34. Pounds in five and a half months -- -- going a little low carb and a little bit lower calories so. Now I'm eating closer to 1213 hundred. Restricting her calorie intake Christina has scaled back her workouts. That's why I've been walking in the park a lot and getting in as many -- as possible and -- through her hunger pains for now it's still fruit. And water but the first theory -- -- that. There -- a slice of pizza and a piece of ice cream cake. Four days later the moment of truth she weighs in at 193. Pounds. Winning -- -- with -- pounds is. -- -- what -- feel like when you stepped on the scale. Relief and excitement. Looking at the -- and singing my progress. I couldn't believe -- and I was so happy -- as Wayne's world self reporting which means healthy wage is taking her -- words. You couldn't really just rely on some of these video may -- game. She did the scales. -- pretty good at detecting Peters and making sure that everybody is actually losing -- and not trying to -- even get money. We meet up with Christina few weeks later he gyms and healthy wage is also here to hand deliver winning. You want your back so here's the check from -- -- U verse 7300. Dollars all the work that I did critics have meaning it's. This is really -- But three weeks after reaching her hard -- -- of 194 pounds. She gets back on the scale the number isn't pretty what is in effect until eleven. So it's -- sixteen -- that's how -- In about three plus weeks gaining back more than a third of her weight loss in just a few weeks. Short term solutions are never the best solutions. You want -- plan that helps you be successful over the long haul. Although I don't tell you what to eat healthy -- says they do offer guidance and support. Obviously we can't. Control people that are -- -- all of our motivational tips and emails all revolve around losing weight -- -- consistent long term way. But despite your weight gain Christina says she isn't worried it's going to be -- it's going to be back -- time I'm sure it. I'm betting on you for Nightline I'm Lindsey Davis in New York.
This transcript has been automatically generated and may not be 100% accurate.