Group-based incentives proved more effective for promoting weight loss among obese employees at the Children’s Hospital of Philadelphia.

As the U.S. grapples with adult overweight and obesity, interest in approaches combating obesity and changing behavior has grown. This randomized controlled trial study examined two incentive designs—an individual- and a group-based design—promoting weight loss among obese employees.

This study of 105 employees at the Children’s Hospital of Philadelphia with a body mass index between 30 and 40 kg/m2 primarily assessed weight loss at 24 weeks; the secondary outcome was weight loss at 36 weeks. Participants weighed in monthly. In the individual group, those meeting or exceeding weight-loss goals received $100 per person per month. For the group incentive, $500 per month was split among participants in five-person groups who met or exceeded monthly weight-loss goals.

Key Findings:

• At 24 weeks, the mean weight loss was greatest among the group-incentive group (4.8 kg), followed by the individual-incentive group (1.7 kg) and the control group (0.5 kg).
• Group-incentive participants received larger payouts ($514.70) than individual participants ($128.60). 
• Twelve weeks after incentives ended, group-incentive participants did not maintain greater weight loss than individual-incentive participants, but did maintain greater weight loss than control group participants.

This study shows that a group-based incentive was more effective than an individual incentive among a trial with equal up-front allocation of resources. Future research should examine the factors improving incentive effectiveness as employers explore ways to promote weight loss among employees.

Read “Getting the Most Out of Financial Incentives for Weight Loss,” an editorial that accompanied the study in the Annals of Internal Medicine.