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Completed

NCT Number: NCT01167634

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.

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Key information

Conditions

Weight Loss Body Weight Body Weight Changes Pathological Conditions, Signs and Symptoms Signs and Symptoms

Age range

18 year–70 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

University of Pennsylvania

Philadelphia, Pennsylvania, 19104, United States

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Deposit contract with a 1:1 match

Behavioral

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.

Deposit contract with a 2:1 match

Behavioral

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.

Deposit Contract with no match

Behavioral

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.

Primary outcomes

  1. Change in Weight

    Time frame: 24 Weeks

    Change in weight between baseline and 24 weeks

Sponsors and collaborators

Lead sponsor

University of Pennsylvania

Other

Collaborators

  • Carnegie Mellon University
  • Harvard University
  • McKinsey & Company
  • incentaHEALTH

Registry information

Important dates

Study start
2011
Primary completion
2012
Study completion
2016
First posted
Jul 22, 2010
Registry last updated
Aug 23, 2017

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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