Dec. 10 -- TUESDAY, Dec. 9 (HealthDay News) -- Putting money in people's pockets can help persuade them to shed fat, suggest American researchers who created two incentive-based approaches for losing weight.
In one, participants played a lottery and received a prize if they achieved or lost more than the target weight. In the other approach -- called "deposit contract" -- participants invested their own money, which they lost if they failed to achieve weight goals.
The 57 volunteers were randomly assigned to a weight-monitoring program involving monthly weigh-ins (control group), or to the same program with one of the two financial incentive plans. All the participants were assigned a weight-loss goal of 16 pounds over 16 weeks.
The volunteers in the incentive groups lost an average of 3.9 pounds more than those in the control group. The average amount of money earned was $378.49 in the deposit contract group and $272.80 in the lottery group.
"Compared with the control group, the lottery group lost a mean of 13.1 pounds and the deposit contract group lost a mean of 14 pounds. About half of those in both incentive groups met the 16-pound target weight loss, 47.4 percent in the deposit contract group and 52.6 percent in the lottery group, whereas 10.5 percent in the control group met the 16-pound target," wrote the researchers from the University of Pennsylvania's School of Medicine and the Wharton School.
Participants in both incentive groups gained weight between the end of the 16-week incentive programs and the end of seven months, but still weighed less at seven months than they did at the start of the study.
"In conclusion, incentive approaches based on behavioral economic concepts appear to be highly effective in inducing initial weight loss. However, this weight loss was not fully sustained and further work is needed to test the effectiveness and cost-effectiveness of these approaches in achieving sustained weight loss," the researchers wrote.
The study was published in the Dec. 10 issue of the Journal of the American Medical Association.
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SOURCE: Journal of the American Medical Association, news release, Dec. 10, 2008