Project Title: A Randomized Controlled Trial of Incentives Vs. Environmental Strategies for Weight Loss

Principal Investigators: Kevin Volpp and Karen Glanz

Project Coordinator: Rebekah Choi

Project Dates: 2014-2019

Obesity is the second leading cause of preventable death in the U.S. and has been linked to high blood pressure, type 2 diabetes, heart disease, and osteoarthritis. Research has shown that losing weight can improve risk factors and reduce the occurrence of chronic disease. In order to achieve these health outcomes, however, the weight loss has to be maintained; yet, successful strategies for long-term maintenance are lacking. To address this knowledge gap, researchers at the University of Pennsylvania Prevention Research Center conducted a study to compare four different promising strategies to achieve weight loss and maintenance of weight loss in obese employee populations.

Researchers recruited 328 employees from the City of Philadelphia, Independence Blue Cross, and the Southeastern Pennsylvania Transportation Authority (SEPTA.) To qualify, the participants must be obese and have at least one other risk factor, such as high blood pressure, diabetes, or smoking. They were then randomly assigned to receive one of four approaches:


  1. Incentive approach – daily lottery-type incentives linked to achieving weight loss goals
  2. Environmental approach – individually tailored environmental strategies around food intake and physical activity
  3. Incentive and environmental approach – a combination of incentives and environmental strategies
  4. Standard approach (i.e., control group) – standard employee wellness benefits and weigh-ins every 6 months


Researchers compared the outcomes of the behavioral economics-based financial incentive and environmental approaches—both separately and together—with the standard approach. This assessment helps determine which approach or combination of approaches works best for achieving weight loss in employee populations. They also assessed the cost of each strategy and compare the cost differences between them relative to their effectiveness (i.e., weight loss achieved).


This research aimed to increase knowledge about effective strategies to achieve weight loss and the maintenance of weight loss among employee populations with high rates of obesity.


Go to Resources to find the toolkits related to this study.



Glanz K, Shaw P, Kwong P, Choi J, Chung A, Zhu J, Huang Q, Hoffer K, Volpp K. Effect of Financial Incentives and Environmental Strategies on Weight Loss in The Healthy Weigh Study: A Randomized Clinical TrialJAMA Network Open 2021;4(9): e2124132. doi:10.1001/jamanetworkopen.2021.24132

Glanz K, Shaw P, Hoffer K, Chung A, Zhu J, Wu R, Huang E, Choi R, Volpp K. The Healthy Weigh study of lottery-based incentives and environmental strategies for weight loss: Design and baseline characteristics. Contemporary Clinical Trials, Jan 2019, Volume 76, pages 24-30.