December 10, 2008
Cash Reward Makes Weight Loss More Effective
Getting skinny and making cash is a powerful combo according to U.S. researchers who said the incentive is more effective than conventional approaches.
Dr. Kevin Volpp of the University of Pennsylvania School of Medicine started the study because he was looking for an effective way to treat obesity.
"We wanted to create a reward system which gave them rewards in the present," said Volpp.
The findings are published in the Journal of the American Medical Association.
Volpp and colleagues studied two kinds of incentive programs for weight loss.
The first was a game-based design where participants played a lottery and were allowed to collect their winnings if they met their weight-loss target.
The lotteries ran daily, and people were told what their winnings would have been if they had met their weight-loss target.
"There is a very strong sense of loss aversion," said Volpp.
"The idea was to create a mechanism where loss aversion would help drive people's motivation," he said.
The second approach was a deposit contract where participants invested a small amount of their own money between 1 cent and $3 per day. They would lose the full amount at the end of the month if they failed to reach their goals.
"You only received your reward at the end of the month if your weight was below the stated goal for the month," Volpp said.
The researchers assigned 57 obese to one of these two groups or a control group.
The participants wanted to lose 16 pounds by the end of four months.
People in the incentive groups lost far more weight than those who got no pay for their efforts, with about half of the participants in each group meeting their weight loss goals.
People in the lottery program earned a total of $378.49 and lost about 13 pounds.
Participants in the second deposit group got $272.80 and lost 14 pounds.
Those in the control group lost about 4 pounds after four months. Their only reward was better fitting jeans.
Volpp said the studies were highly effective at creating short-term weight loss.
However, he said when the money stopped flowing, the weight came back.
"We need to establish whether they can be effective in sustaining weight loss as well," he said.
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