University Of Pennsylvania Weight Loss Study

Summary

This is a 4-arm, randomized controlled trial to evaluate the effectiveness of financial incentives to motivate and sustain long-term weight loss. The study will recruit eligible employees at a large health management company to participate in a 6-month weight loss program and have weight measurements for an additional 3-month follow-up period. The primary outcome measure in this randomized controlled trial will be pounds of weight lost. The experimental groups will include variations of deposit contracts (participants put their own money at risk, and lose that money if they fail to achieve their weight loss goal) and fixed payments. The use of deposit contracts is a powerful mechanism for inducing behavior change that is based on loss aversion, a psychological concept first described by Nobel Prize winner Daniel Kahneman and Amos Tversky in 1979. A deposit contract takes advantage of the fact that people typically feel the pain of a loss more than the pleasure of a gain, increasing ones motivation to reach a goal.

The study hypotheses are 1) mean weight loss will be greater in all intervention groups compared to the control group by the end of 24 weeks; and 2) individuals in the intervention groups will have a lower mean weight at the end of the 3-month follow-up period than individuals in the control group.

Conditions

• Weight Loss

Interventions

BEHAVIORAL

Deposit contract with a 1:1 match

Daily weigh-in for 24 weeks and if each daily goal met daily deposit amount is paid back with an additional matched amount equal to deposited amount. Final weigh-in at 36 weeks with no financial incentive or deposit made.

BEHAVIORAL

Deposit contract with a 2:1 match

Daily weigh-in for 24 weeks and if each daily goal met daily deposit amount is paid back with an additional matched amount twice the amount equal to deposited amount. Final weigh-in at 36 weeks with no financial incentive or deposit made.

BEHAVIORAL

Deposit Contract with no match

Daily weigh-in for 24 weeks and if each daily goal met the daily deposit amount is paid back. Final weigh-in at 36 weeks with no financial incentive or deposit made.

Sponsors & Collaborators

• Carnegie Mellon University

  collaborator OTHER

• Harvard University

  collaborator OTHER

• incentaHEALTH

  collaborator INDUSTRY

• McKinsey & Company

  collaborator UNKNOWN

• University of Pennsylvania

  lead OTHER

Principal Investigators

• Kevin G. Volpp, MD, PhD · University of Pennsylvania

• George Loewenstein, PhD · Carnegie Mellon University

• Heather Schofield, MS · Harvard University

• Jeffrey T Kullgren, MD, MPH · University of Pennsylvania

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

NONE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

70 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2011-05-24

Primary Completion

2012-03-15

Completion

2016-07-31

Countries

• United States

Study Locations