Design, Sites, and Data Sources
MDRC’s study examined whether a financial incentive program encouraged overweight and obese individuals to lose weight and whether the weight loss was sustained after the end of the incentive program. A total of 49 employees in MDRC’s New York and Oakland, California, offices were randomly assigned to either the program (n=25) or the control group (n=24). To be eligible, they had to have a body mass index (BMI) of 25 or higher and agree to the terms of the study. Seventy percent were women and the mean age was 40.6 years (range of 23 to 63). The average BMI was 30.9 (range of 25.2 to 44.6).
All participants in both the program and control groups received an initial one-hour consultation and goal-setting session with a dietician. For the next six months, all participants were required to meet with the dietician once a month to get weighed. All participants received $30 for attending the monthly weigh-in. Individuals in the program group were also given a scale and were asked to weigh themselves every morning and enter their weight on the study’s website. As an incentive, the program group members were eligible to win a daily lottery for entering their weight onto a website. They had a 1 in 5 chance of winning $15 and 1 in 100 chance of winning $135. The winnings accumulated and the participants received the winnings only if they were at or below their weight loss goal at the end-of-the-month weigh-in.