University Of Pennsylvania Weight Loss Study

University of Pennsylvania

Status: Completed

Conditions: Weight Loss

Treatments: Behavioral: Deposit Contract with no match; Behavioral: Deposit contract with a 2:1 match; Behavioral: Deposit contract with a 1:1 match

Study type: Interventional

Funder types: Other; Industry

Identifiers

NCT01167634

813407

Details and patient eligibility

About

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.

Enrollment: 132 patients

Sex: All

Ages: 18 to 70 years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

---

132 participants in 4 patient groups

1

No Intervention group

2

Experimental group

Description:

Deposit contract with a 1:1 match

Treatment:

Behavioral: Deposit contract with a 1:1 match

3

Experimental group

Description:

Deposit contract with a 2:1 match

Treatment:

Behavioral: Deposit contract with a 2:1 match

Experimental 4

Experimental group

Description:

Deposit contract with no match

Treatment:

Behavioral: Deposit Contract with no match