University Of Pennsylvania Weight Loss Study

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.

Study Overview

• Status: Completed
• Conditions: Weight Loss
• Intervention / Treatment: Behavioral: Deposit contract with a 1:1 match; Behavioral: Deposit contract with a 2:1 match; Behavioral: Deposit Contract with no match

• Study Type: Interventional
• Enrollment (Actual): 132
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19104
      • University of Pennsylvania

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 70 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Aged 18 to 70 (inclusive)
• BMI between 30 and 50 (inclusive)

Exclusion Criteria:

• Inability to consent
• No known Illiteracy and/or inability to speak, read, and write English
• Participation in another weight loss program
• Participation in another research study
• Current treatment for drug or alcohol use
• Consumption of 5 alcoholic drinks per day
• Myocardial infarction or stroke within the past 6 months
• Uncontrolled hypertension (defined as BP170 mm Hg systolic or BP110 mm Hg diastolic)
• Current addiction to prescription medicines or street drugs
• Serious psychiatric diagnoses (severe depression, schizophrenia)
• Pregnancy
• Diabetic and using any medicine besides metformin to control blood sugars
• Metastatic cancer
• Unstable medical conditions that would likely prevent the subject from completing the study
• Previous diagnosis of an eating disorder
• History of unsafe weight loss behaviors such as binging or the use of laxatives

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
No Intervention: 1
Experimental: 2; Deposit contract with a 1:1 match	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.
Experimental: 3; Deposit contract with a 2:1 match	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.
Experimental: Experimental 4; Deposit contract with no match	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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Weight	Change in weight between baseline and 24 weeks	24 Weeks

Collaborators and Investigators

• Sponsor: University of Pennsylvania
• Collaborators: Harvard University; Carnegie Mellon University; incentaHEALTH; McKinsey & Company
• Investigators: Study Director: George Loewenstein, PhD, Carnegie Mellon University; Study Chair: Kevin G. Volpp, MD, PhD, University of Pennsylvania; Study Director: Heather Schofield, MS, Harvard University

Publications and helpful links

General Publications

• Kullgren JT, Troxel AB, Loewenstein G, Norton LA, Gatto D, Tao Y, Zhu J, Schofield H, Shea JA, Asch DA, Pellathy T, Driggers J, Volpp KG. A Randomized Controlled Trial of Employer Matching of Employees' Monetary Contributions to Deposit Contracts to Promote Weight Loss. Am J Health Promot. 2016 Jul;30(6):441-52. doi: 10.1177/0890117116658210.

Study record dates

Study Major Dates

• Study Start (Actual): May 24, 2011
• Primary Completion (Actual): March 15, 2012
• Study Completion (Actual): July 1, 2016

Study Registration Dates

• First Submitted: July 20, 2010
• First Submitted That Met QC Criteria: July 20, 2010
• First Posted (Estimate): July 22, 2010

Study Record Updates

• Last Update Posted (Actual): August 23, 2017
• Last Update Submitted That Met QC Criteria: August 22, 2017
• Last Verified: August 1, 2017

More Information

Terms related to this study

• Keywords: Motivation; Weight Loss; Contracts
• Additional Relevant MeSH Terms: Body Weight Changes; Weight Loss; Body Weight
• Other Study ID Numbers: 813407