Mayo’s Incentive and Obesity Study: Overplayed, Undisclosed, or Undermined?

The Mayo Clinic announced yesterday a study showing that “financial incentives help weight loss study participants drop pounds, stick with program.” The study will be presented tomorrow at the American College of Cardiology conference in San Francisco. The findings are already attracting more than their fair share of media attention, but [spoiler alert!] there may be more to this story than meets the eye.

Mayo’s news release describes the study design: “All [100] participants were given a goal of losing 4 pounds per month up to a predetermined goal weight. Participants were weighed monthly for one year… 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 subjects were Mayo Clinic employees. 62% of the incentivized participants completed the program, compared to only 26% of the unincentivized participants. Participants receiving incentives lost an average of 9.08 pounds, compared with 2.34 pounds for those not receiving incentives.

This is a small study, but it sure paints a rosy picture of incentives. It will be interesting to learn the details from tomorrow’s presentation.

Will the presentation acknowledge that, while it seems inevitable that overweight people are more likely to stick with a program and achieve weight loss goals if they’re paid to do so, previous research has demonstrated the potential undermining effect of lifestyle incentives. As a result of the undermining effect, incentivized weight loss participants may be more likely to regain weight after the cash stops rolling in.

And we can only hope that, when the Mayo study is publicized more broadly, its pitchmen appropriately disclose that the study’s lead author is the scientific advisor and reportedly a stock holder of GymPact, the mobile app that promises to “incentivize your exercise.”