Can you pay people to lose weight?

Yes, “economic incentives produced significant weight loss” short-term, according to researchers in Pennsylvania.

First, the details.

  • 57 obese people (BMI between 30 and 40 kg/m2) participated in a program to lose 16 pounds over 4 months.
  • After a one-on-one consultation with a dietitian about diet and exercise the participants were randomly assigned to monthly weigh-ins under 1 of 3 conditions.
    • No incentive.
    • Deposit-contract incentive: patients deposited their money, which they could earn back in matched funds, up to $252 a month, by meeting weight targets.
    • Lottery incentive: patients could win about $3 for every day they met weight targets with the possibility of winning $10 or $100 — a better chance of winning the $10.
  • Patients were given daily weight goals and reported progress to nurses who provided feedback on the amount of money earned for reaching goals.

And, the results.

  • The incentive groups lost significantly more weight than the control group (4 lb).
  • Compared to the no incentive group, the lottery group lost 13 lb and the deposit contract group lost 14 lb — both significant differences.
  • About half of those in the incentive groups met the 16-lb target weight loss — significant vs the control group.
  • Differences between the incentive groups were not significant.
  • 3 months after the study the participants gained weight, although the differences between the incentive groups and no incentive were still significant.

The bottom line?
The magnitude of weight loss with the incentive groups has been shown to improve outcomes such as blood pressure, control of blood sugar levels, and cholesterol levels, said the authors.

Whether longer-term use of financial incentives would have helped these people sustain their weight loss is an open question.

12/12/08 21:09 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.