(CNN) -- The $10,000 prize caught Jordan Teuscher's attention.
He read the rules carefully. Teams of five would compete against others from around the country to have the highest percentage of weight loss after 12 weeks. To prevent unhealthy dieting, no one person could lose more than 16.6% of their total body weight.
Teuscher wasn't extremely obese, but he had put on more than a few pounds since getting married and starting law school. His family was naturally competitive. If he could persuade them to participate, he thought, they had a good chance of winning the HealthyWage challenge.
He talked to his uncle, Jon Whicker, and his sister, who had auditioned for "The Biggest Loser" but were not accepted. They agreed to join his team. His mom and dad also hopped on board. The family decided on a name -- "Will Work for Less Food" -- and paid their $75 entry fees.
For three months, they cut out sugar and refined carbohydrates; they avoided eating late at night and added exercise to their schedules. They vied for first place with a team named Bravo5A, winning and losing small challenges along the way that only pushed them harder.
"In general, I'm a warrior," Whicker says. And as a warrior, "you're never quite happy with just being ahead -- you want to be way ahead."
In the end, they emerged victorious -- dropping a combined 255 pounds (16% of their total body weight) to win the competition and the $10,000 prize.
"It's been nice to have it off -- to be able to fit into your old clothes, feel comfortable in groups," says Teuscher, who lost 47 pounds. "I feel healthier. Happier."
Whicker used his share of the winnings to put a new motor in his old Mustang. But the real benefits were less materialistic -- his cholesterol went down, his blood pressure normalized and his acid reflux disappeared.
"My son the other day got my wallet and pulled out my driver's license picture ... he looked at it and looked at my wife and said, 'That doesn't look like Dad anymore,'" Whicker said with a laugh.
Teuscher and Whicker have joined another HealthyWage challenge to continue their weight loss journey.
The company offers three programs. The Matchup challenge asks teams of five to compete for $10,000; the 10% Challenge allows users to double their money if they lose 10% of their weight in six months; and the BMI Challenge pays users $100 to go from an obese BMI to a healthy BMI in 12 months.
HealthyWage isn't the only company to jump on the motivation money train. Competitors such as DietBet.com, GymPact and StickK ask users to put their hard-earned cash on the line in hopes of getting healthy and wealthy. And many company benefits programs have started offering financial incentives to employees who drop weight or quit smoking in hopes of reducing health care costs.
There's scientific evidence to support their business model. HealthyWage co-founder David Roddenberry started the company in 2009 after seeing a study in the Journal of the American Medical Association that showed financial incentives could encourage weight loss.
Last year, a Mayo Clinic study found people who received financial incentives stuck with healthy behaviors longer -- losing, on average, seven more pounds than their colleagues whose wallets weren't linked to weight loss.
Of course, money isn't the only motivator in weight loss challenges.
"I think what inspired me the most was the fact that my team members were going to lose money," Teuscher says. "I was really afraid I would be the person that ruined it for everyone."
Peer pressure can help groups lose more weight than individuals fighting for a cash prize, according to a new study published in the journal Annals of Internal Medicine.
Researchers followed two groups of employees at the Children's Hospital of Philadelphia. Individuals in the first group were offered $100 each month that they met or exceeded their weight loss goals. The second group was organized into teams of five; each team was given $500 to split among those who met their goals, increasing the competition between team members.
People in the second group lost almost three times as much weight than those in the first, according to the study.
"We've found a lot of success among teams where you already know your teammates," Roddenberry says. "People are more motivated by not letting their team down than they are by doing it for themselves."
The company has also identified other key factors that lead to effective weight loss.
"A really big headline number is important," Roddenberry says. "100 bucks, 200, 400, is not going to move the needle with behavior change. But if you say you can win $10,000 ..."
Also important is having a stake in the competition. People who make an investment -- such as paying $150 up front -- are more motivated by losing that money than by doubling it, Roddenberry says.
Of course, not everyone has a competitive personality.
Men tend to do better on HealthyWage than women, he notes, and the website attracts more users who are "money motivated" -- coupon clippers or discount shoppers who value the return on their investment.
"It's so personal," Roddenberry says of weight loss. "Different people have different motivations."
Right now HealthyWage is "one size fits all," he says. But in the future, the company hopes to provide customized programs that will fit each person's needs, whether that's a bigger prize, a shorter time period or weekly incentives.
It's tough, Teuscher says, to stay on track without the proper motivation. "Once you get to where you are you miss what you had before. Food is a big temptation."
He's joined the BMI Challenge in hopes of getting down to 180 pounds and doubling his initial investment.
Whicker joined another Matchup team challenge with his wife, Alisa, after the first; they took fourth place. Now he's participating in the 10% Challenge to lose 10% of his body weight in six months.
He doesn't track calories, focusing instead on eating five to six small healthy meals a day. He hits the gym for an hour to two hours most days and takes his kids, Riley, 6, and Samantha, 2, out to ride bikes or swim at the pool.
Since June 2012, when he first joined HealthyWage, he's lost 128 pounds.
"I'm still getting there," he says. "Part of it is time; part of it is understanding what really matters in life. ... As you start to have kids, suddenly you come to the realization that there (are) more people depending on you than yourself."