Understanding Mechanisms of Health Behavior Change

This research seeks to examine psychological factors that may impact relationship between incentives and health behavior engagement, specifically fruit and vegetable consumption. Additionally, it will compare the impact of two different incentive schedules on behavior engagement, one providing immediate rewards (i.e. rewards received on a daily basis) and another providing delayed rewards (i.e. rewards received at the end of the study period), with a control condition in which no rewards are offered. Study participants will provide reports of their fruit and vegetable consumption each day for three weeks, and in the two incentive conditions, they will receive small monetary rewards for their fruit and vegetable consumption. Following the three week reporting and reward period, participants will complete two additional assessments, measuring psychological constructs and behavior engagement following the cessation of rewards. The study will also examine how cognitive and anthropomorphic factors may contribute to intervention response and the effects on psychological constructs.

Study Overview

• Status: Completed
• Conditions: Diet Modification; Overweight and Obesity; Incentives
• Intervention / Treatment: Behavioral: self-monitoring; Behavioral: daily monetary incentives; Behavioral: delayed lump sum monetary incentives

• Study Type: Interventional
• Enrollment (Actual): 68
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Colorado
    • Boulder, Colorado, United States, 80309
      • University of Colorado Boulder

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Consume fewer than 3 servings/day of fruits and vegetables
• Daily access to internet for 3 weeks following baseline session
• Have or are willing to create an account on PayPal
• BMI greater than or equal to 25, from self-reported height and weight

Exclusion Criteria:

-

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Self-Monitoring Control; Daily tracking of fruit and vegetable consumption	Behavioral: self-monitoring; recording fruit and vegetable consumption
Experimental: Daily Incentives; Incentives for fruit and vegetable consumption delivered daily	Behavioral: self-monitoring; recording fruit and vegetable consumption; Behavioral: daily monetary incentives; daily payments for consuming fruits and vegetables
Experimental: Delayed Lump Sum Incentives; Incentives for fruit and vegetable consumption delivered in a lump sum at the end of the intervention	Behavioral: self-monitoring; recording fruit and vegetable consumption; Behavioral: delayed lump sum monetary incentives; lump sum payments for consuming fruits and vegetables

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Fruit and vegetable consumption, servings per week	3 Weeks
Fruit and vegetable consumption, servings per week	5 Weeks
Perceived behavioral control scale score	3 Weeks
Perceived behavioral control scale score	5 Weeks
Attitude scale score	3 Weeks
Attitude scale score	5 Weeks

Secondary Outcome Measures

Outcome Measure	Time Frame
Intrinsic motivation scale score	3 Weeks
Intrinsic motivation scale score	5 Weeks

Collaborators and Investigators

• Sponsor: University of Colorado, Boulder

Study record dates

Study Major Dates

• Study Start (Actual): July 13, 2017
• Primary Completion (Actual): February 21, 2018
• Study Completion (Actual): March 30, 2018

Study Registration Dates

• First Submitted: June 16, 2017
• First Submitted That Met QC Criteria: June 16, 2017
• First Posted (Actual): June 20, 2017

Study Record Updates

• Last Update Posted (Actual): August 1, 2023
• Last Update Submitted That Met QC Criteria: July 27, 2023
• Last Verified: July 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Overnutrition; Nutrition Disorders; Body Weight; Overweight
• Other Study ID Numbers: 16-0700

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No