UPenn PRC researchers studied how financial incentives and environmental strategies impact behavior change when losing weight. After the study was completed, they interviewed high- and low-success participants to learn more about how the trial did or did not work.  By examining participant perceptions, they gained insights into factors related to the effectiveness – or lack of effectiveness – of these interventions.

Read the latest publication from the Healthy Weigh Study in volume 14/issue 3 of BMJ Open.

Trial participants who successfully lost weight differed from those who did not lose weight in several ways.

Successful Participants:

– Had robust prior attempts at dietary and exercise modification.

– Actively engaged when they encountered obstacles.

– Received substantial social support.

– Routinized dietary and exercise changes.

– Often considered weight loss as its own reward, even without incentives.

Interestingly, neither group could clearly articulate the details of the incentive intervention or identify payments as incentives or study payments.

With or without a specific incentive or environmental intervention – it appears that successful weight loss is linked to actively trying, having social support, and being intrinsically motivated.


Glanz K, Kather C, Chung A, et al. Qualitative study of perceptions of factors contributing to success or failure among participants in a US weight loss trial of financial incentives and environmental change strategies. BMJ Open 2024;14:e078111.

Main Results Paper: 

Glanz K, Shaw PA, Kwong PL, Choi J, Chung A, Zhu J, Huang Q, Hoffer K, Volpp KG.  Effect of financial incentives and environmental strategies on weight loss in The Healthy Weigh Study: A Randomized Controlled Trial. JAMA Network Open, 2021;doi:10.1001/jamanetworkopen.2021.24132

Protocol Paper:

Glanz K, Shaw P, Hoffer K, Chung A, Zhu J, Wu R, Huang Q, Choi J, Volpp K.  The Healthy Weigh Study of Lottery-based Incentives and Environmental Strategies for Weight Loss: Design and Baseline Characteristics.  Contemporary Clinical Trials, 2019; 76: 24-30.