Previous studies have shown that financial incentives help people lose weight, but this study examined a larger group of participants (100) over a longer period (one year), says lead author Steven Driver, M.D., an internal medicine resident at Mayo Clinic. One hundred healthy adult Mayo employees or their dependents, ages 18-63 with a body mass index of 30 to 39.9 kg/m2, were assigned to one of four weight loss groups: two with financial incentives and two without. An adult who has a body mass index -- a calculation determined by using weight and height -- of 30 or higher is considered obese, according the Centers for Disease Control and Prevention.
All participants were given of goal of losing 4 pounds per month up to a predetermined goal weight. Participants were weighed monthly for one year; previous financial incentive studies followed patients for 12 and 36 weeks. Participants in the incentive groups who met their goals received $20 per month, while those who failed to meet their targets paid $20 each month into a bonus pool. Participants in both incentive groups who completed the study were eligible to win the pool by lottery.
Study completion rates for the incentive groups were significant compared with the non-incentive groups: 62 percent versus 26 percent. In the incentive groups, participants mean weight loss was 9.08 pounds, compared with 2.34 pounds for the non-incentive groups.
"The take-home message is that sustained weight loss can be achieved by financial incentives," Dr. Driver says. "The financial incentives can improve results, and improve compliance and adherence."
Researchers found that even participants in the incentive group who paid penalties were more likely to continue their participation in the study than those in the non-incentive groups, Dr. Driver says.
Senior study author Donald Hensrud, M.D., preventive medicine expert at Mayo Clinic and medical editor of The Mayo Clinic Diet, says obesity continues to be a major concern in the United States because extra weight contributes to many conditions, such as heart disease and diabetes.
"Traditional therapies are not working for a lot of people, so people are looking for creative ways to help people lose weight and keep it off," Dr. Hensrud says. "The results of this study show the potential of financial incentives."