Examining Valence-based Effects in Self-Monitoring Feedback Messages

Examining Valence-based Effects in Self-monitoring Feedback Messages, in the Development of a Novel Semi-automated Self-monitoring Feedback System for Obesity Treatment

The purpose of this research study is to learn how to identify the most effective ways to provide weekly feedback on participants' progress toward intervention goals during a weight loss program.

Study Overview

• Status: Recruiting
• Conditions: Obesity (Disorder); Obesity & Overweight
• Intervention / Treatment: Behavioral: Positive Reinforcement; Behavioral: Positive Reinforcement + Areas for Change

Detailed Description

This micro-randomized factorial trial is designed to provide information about how to optimize self-monitoring feedback within a behavioral weight management intervention. All participants will attend a "Weight Loss 101" session that covers foundational weight loss education and behavioral skills training. During this session, they will also learn how to use study-provided tools to track their dietary intake, physical activity, and weight.

Each weekly feedback message will be composed by a trained interventionist. Participants will be randomized each week to one of the two conditions to examine how the tone and composition of feedback messages impact participant behaviors and weight loss.

The main questions that this study aims to answer are:

• How does the composition of supportive feedback and ideas for potential changes in dietary or physical activity behaviors impact weight loss.
• How is this feedback affected by individual or contextual factors?

• Study Type: Interventional
• Enrollment (Estimated): 127
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Teace Markwalter, M.P.H., CHES; Phone Number: 540-239-6283; Email: bdwcp@virginia.edu
• Study Contact Backup: Name: Maddie Glover, B.S.; Phone Number: 4342432387; Email: ktg7zr@virginia.edu

Study Locations

• United States
  • Virginia
    • Charlottesville, Virginia, United States, 22901
      • Recruiting
      • University of Virginia
      • Contact: Maddie Glover, B.S.; Phone Number: 4342432387; Email: ktg7zr@virginia.edu
      • Contact: Teace Markwalter, MPH, CHES; Phone Number: 540-239-6283; Email: bdwcp@virginia.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Age greater than or equal to 18 years
• BMI greater than or equal to 25.0 kg/m2
• Weight less than or equal to 175 kg (due to scale limit)
• Own a smartphone compatible with Fitbit (e.g., an Apple iPhone running iOS 16.4 or higher or Android smartphone running Android 11 or higher) with a cellular and data plan

Exclusion Criteria:

• Weight greater than 175 kg (due to a weight limit of the study-provided scale)
• Smartphone device owned deemed incompatible with the Fitbit App
• History of bariatric surgery or plans to obtain bariatric surgery during the study period
• Current use of weight loss medications, or use of weight loss medications in the 6 months prior to initial pre-screening
• Currently participating in a weight-loss program
• Weight loss of greater than or equal to 10 lbs in the 6 months prior to initial pre-screening
• Physical limitations that prevent walking at a brisk pace for at least 10 minutes without stopping
• Use of a pacemaker or other implanted medical device
• Currently pregnant
• Currently breastfeeding
• Less than 1-year post-partum
• Plans to become pregnant within the study period
• Lack of written confirmation that the potential participant has discussed study participation with their physician if they have been diagnosed with diabetes, hypertension, or has have a history of coronary heart disease
• One or more study participants living in the household (enrollment limited to one participant per household)
• Medical conditions that contraindicate weight loss or prevent completion of the study (e.g., current diagnosis of cancer or terminal illness, dementia, etc.)
• Recent (in the past 6 months) changes in medications that affect weight
• Self-reported eating disorder within past 5 years
• Unable to complete the 17-week study (due to plans to relocate during the study period, etc.)
• Unable or unwilling to provide informed consent
• Unable to read English at the 5th grade level
• Unwilling to accept random assignment
• Unable or unwilling to download the study smartphone application, wear the physical activity monitor, or use the study e-scale
• Failure to complete baseline assessment measures
• Failure to complete at least 4 out of 6 days of self-monitoring dietary and weight self-monitoring during the behavioral run-in period
• Any other condition(s) which, in the opinion of the Principal Investigator, would adversely affect participation in the study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Self Monitoring Feedback; Participants in this study will complete a 60-minute "Weight Loss 101" session and use study-provided tools to record their daily food intake, physical activity, and weight. After a one-week run-in period, they will begin receiving weekly feedback messages. The content and emphasis of these messages will differ between 2 conditions: positive reinforcement vs. positive reinforcement + areas for change.

Behavioral: Positive Reinforcement; Feedback composed by a study interventionist that focuses exclusively on positively reinforcing the participant's progress toward achieving their goals.; Behavioral: Positive Reinforcement + Areas for Change; Feedback provided by a study interventionist that combines positive reinforcement of the participant's progress with constructive guidance on areas for improvement to support successful goal attainment.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Weight change	Mixed-effects models will be used to investigate the impact of each feedback condition on our primary outcome of weight change. Fitted model estimates will be used to calculate the slope of weight change from day 1 (the day a feedback message is delivered) through day 7 of each week. Positive slopes indicate weight gain, while negative slopes indicate weight loss.	7 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Frequency of self-monitoring physical activity	Frequency of self-monitoring physical activity will be defined as the number of "valid" days (0-7) of Fitbit use the week after a feedback message is received (from day 1, the day that a feedback message is received, to day 7).	7 days
Frequency of self-monitoring weight	Frequency of self-monitoring weight will be defined as the number of days (0-7) in the week following a feedback message (from day 1, the day that a feedback message is received, to day 7) in which the participant records a valid (non-outlier) e-scale weight.	7 days
Frequency of self-monitoring dietary intake	A valid "day" of dietary self-monitoring will be defined as ≥ 800 kcal recorded, consistent with prior research. Frequency is calculated as the number of valid days (0-7) recorded the week after a feedback message is delivered (from day 1, the day that a feedback message is received, to day 7).	7 days
Total caloric intake	Total caloric intake will be calculated by summing calories consumed during the week following a feedback message is received (from day 1, the day that a feedback message is received, to day 7)	7 days
Calorie goal attainment	Calorie goal attainment for each day during the week after a feedback message is received (from day 1, the day a feedback message is received, to day 7). Calorie goal attainment will be calculated as [TOTAL KCAL INTAKE FOR THE DAY] - [CALORIE GOAL]. Daily difference scores for the 7 days will be averaged across the week to determine overall adherence to the caloric intake goal.	7 days
Physical activity minutes	Total minutes of physical activity will be calculated by summing each days' total "active zone minutes" during the week after a feedback message is delivered (from day 1, the day that a feedback message is received, to day 7)	7 days
Physical activity goal attainment	Physical activity goal attainment for each day of the week after a feedback message is received (from day 1, the day that a feedback message is received, to day 7) will be calculated as [TOTAL PHYSICAL ACTIVITY MINUTES] - [PHYSICAL ACTIVITY GOAL]. Daily difference scores will be averaged over the week to assess overall adherence to the physical activity goal during that study week.	7 days

Collaborators and Investigators

• Sponsor: University of Virginia
• Collaborators: University of Florida; Wake Forest University Health Sciences
• Investigators: Principal Investigator: Becca Krukowski, Ph.D., University of Virginia

Study record dates

Study Major Dates

• Study Start (Actual): March 23, 2026
• Primary Completion (Estimated): May 1, 2027
• Study Completion (Estimated): June 1, 2027

Study Registration Dates

• First Submitted: December 5, 2025
• First Submitted That Met QC Criteria: December 5, 2025
• First Posted (Actual): December 18, 2025

Study Record Updates

• Last Update Posted (Actual): March 31, 2026
• Last Update Submitted That Met QC Criteria: March 30, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: physical activity; weight loss; digital health; self-monitoring; wearables; lifestyle intervention; smartphone app; activity monitor; behavior change; dietary change; e-scale; self-monitor activity
• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Body Weight Changes; Pathological Conditions, Signs and Symptoms; Behavior; Nutritional and Metabolic Diseases; Signs and Symptoms; Overweight; Obesity; Weight Loss; Motor Activity
• Other Study ID Numbers: IRB302281

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Individual-level participant data will be de-identified and made available at the time of publication of peer-reviewed manuscript(s) based on the data. Study data will be shared via the Zenodo data repository at https://zenodo.org/. Analytic code will be made publicly available via Supplementary files for any publications and/or via Zenodo through a Zenodo-GitHub link. Study protocol, informed consent form, statistical analysis plan will also be available to be shared via clinicaltrials.gov.
• IPD Sharing Time Frame: De-identified, individual-level participant data will be made available at the time of publication of peer-reviewed manuscript(s) based on the data.
• IPD Sharing Access Criteria: Data will be made available via the Zenodo data repository (https://zenodo.org).
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; ANALYTIC_CODE

Drug and device information, study documents

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