Just-in-time Adaptive Intervention Messaging in a Digital Weight Loss Intervention for Young Adults

NCT05625061 | Completed Results

• 2 other identifiers: 22-01701R01HL161373
• Study Type: interventional
• Target: 255
• Locations: 1 country
• Sites: 1

Brief Summary

The purpose of this micro-randomized trial is to evaluate the effects of 7 types of intervention messages targeting specific behavior change techniques (i.e., BCT messages) delivered in "just-in-time" (JIT) moments on daily achievement of weight-related behavioral goals among n=201 young adults with overweight and obesity, participating in a digital, mobile comprehensive lifestyle intervention. "Just-in-time adaptive interventions" (JITAIs) are an alternative to the "one size fits all" approach of mobile intervention development that can provide tailored, real-time messaging and support for young adults.

Conditions

Obesity; Overweight; Overweight and Obesity

Keywords

Mobile intervention; Diet; Physical Activity; Behavioral weight loss

Outcome Measures

Primary Outcomes (3)

• Met Daily Weighing Goal

  Each observation corresponds to a microrandomization decision point; the reported value reflects the outcome measured within that unit. Among the randomization observations in which the participant had not yet weighed, this outcome is the number of observations in which the daily weighing goal was met after receiving or not receiving a message and before the end of the day. Observations are accumulated across participants and across time. On the day of randomization, a dichotomous outcome of whether a participant weighed or did not weigh is calculated.

  Daily throughout the study, a total of up to 24 weeks

• Met Daily Active Minutes Goal

  Each observation corresponds to a microrandomization decision point; the reported value reflects the outcome measured within that unit. Among the randomization observations in which the participant had not yet met their active minutes goal, this outcome is the number of observations in which the daily active minutes goal was met after receiving or not receiving a message and before the end of the day. Observations are accumulated across participants and across time. On the day of randomization, a dichotomous outcome of whether a participant met or did not meet their active minutes goal is calculated.

  Daily throughout the study, a total of up to 24 weeks

• At or Under Daily Red Foods Limit

  Each observation corresponds to a microrandomization decision point; the reported value reflects the outcome measured within that unit. Among the randomization observations in which the participant had not yet exceeded their red foods limit, this outcome is the number of observations in which the participant stayed at or under their daily red foods limit after receiving or not receiving a message and before the end of the day. Observations are accumulated across participants and across time. On the day of randomization, a dichotomous outcome of whether a participant stayed at or under their red foods limit or did not is calculated.

  Daily throughout the study, a total of up to 24 weeks

Secondary Outcomes (10)

• Weight Change

  Baseline, 6 months

• Percent Weight Change

  Baseline, 6 months

• Proportion of Days Met Daily Weighing Goal

  Daily throughout the study, a total of up to 24 weeks

• Proportion of Daily Active Minutes Goal Met

  Daily throughout the study, a total of up to 24 weeks

• Proportion of Daily Red Foods Limit

  Daily throughout the study, a total of up to 24 weeks

Study Arms (8)

Core Behavioral Weight Loss (BWL) Intervention

EXPERIMENTAL

Behavioral weight loss core intervention, includes activity tracker, wireless scale, daily self-weighing, and smartphone app with weekly behavioral lessons, food tracking log, weekly tailored feedback summary, and daily weight-related behavioral goals. Core intervention component is combined with each of the 7 intervention messages to be tested repeatedly over time.

Behavioral: Core Behavioral Weight Loss (BWL) Intervention

Core BWL Intervention + BCT 1 Message (Action Planning)

EXPERIMENTAL

Core BWL Intervention + Message testing the Behavior Change Technique "Action Planning"

Behavioral: Behavior Change Technique 1 Message (Action Planning)

Core BWL Intervention + BCT 2 Message (Discrepancy)

EXPERIMENTAL

Core BWL Intervention + Message testing the Behavior Change Technique "Discrepancy Between Current Behavior and Goal"

Behavioral: Behavior Change Technique 2 Message (Discrepancy between Current Behavior and Goal)

Core BWL Intervention + BCT 3 Message (Feedback on Outcome of Behavior)

EXPERIMENTAL

Core BWL Intervention + Message testing the Behavior Change Technique "Feedback on Outcome of Behavior"

Behavioral: Behavior Change Technique 3 Message (Feedback on Outcome of Behavior)

Core BWL Intervention + BCT 4 Message (Social Support)

EXPERIMENTAL

Core BWL Intervention + Message testing the Behavior Change Technique "Social Support"

Behavioral: Behavior Change Technique 4 Message (Social Support)

Core BWL Intervention + BCT 5 Message (Social Comparison)

EXPERIMENTAL

Core BWL Intervention + Message testing the Behavior Change Technique "Social Comparison"

Behavioral: Behavior Change Technique 5 Message (Social Comparison)

Core BWL Intervention + BCT 6 Message (Social Reward)

EXPERIMENTAL

Core BWL Intervention + Message testing the Behavior Change Technique "Social Reward"

Behavioral: Behavior Change Technique 6 Message (Social Reward)

Core BWL Intervention + BCT 7 Message (Focus on Past Success)

EXPERIMENTAL

Core BWL Intervention + Message testing the Behavior Change Technique "Focus on Past Success"

Behavioral: Behavior Change Technique 7 Message (Focus on Past Success)

Interventions

Core Behavioral Weight Loss (BWL) Intervention BEHAVIORAL

All participants receive a mobile behavioral weight loss intervention delivered through a study smartphone app with weekly behavioral lessons, food tracking log, weekly tailored feedback, and daily weight-related behavioral goals; a connected physical activity tracker and wireless scale. As micro-randomized trials are sequential, full factorial experiments, this core intervention component is combined with each of the 7 intervention messages (i.e., Behavior Change Technique (BCT) messages) to be tested repeatedly over time. Participants will be evaluated at each of 3 decision points (morning, midday, evening) on each day of the study, and if eligible then micro-randomized, to receive or not receive, 1 of 7 types of daily intervention messages promoting achievement of proximal weight-related behavioral goals.

Core Behavioral Weight Loss (BWL) Intervention

Behavior Change Technique 1 Message (Action Planning) BEHAVIORAL

Core BWL Intervention + Message in smartphone app prompts detailed planning of performance of one of the 3 target behaviors (daily weighing, active minutes, red food intake).

Core BWL Intervention + BCT 1 Message (Action Planning)

Behavior Change Technique 2 Message (Discrepancy between Current Behavior and Goal) BEHAVIORAL

Core BWL Intervention + Message in smartphone app provides feedback on each of the 3 target behaviors (daily weighing, active minutes, red food intake) in the form of information drawing attention to discrepancies between participants' current behavior and participants' daily goals.

Core BWL Intervention + BCT 2 Message (Discrepancy)

Behavior Change Technique 3 Message (Feedback on Outcome of Behavior) BEHAVIORAL

Core BWL Intervention + Message in smartphone app provides participants with feedback on their weight change, relating it to their performance on one of the 3 target behaviors (daily weighing, active minutes, red food intake).

Core BWL Intervention + BCT 3 Message (Feedback on Outcome of Behavior)

Behavior Change Technique 4 Message (Social Support) BEHAVIORAL

Core BWL Intervention + Message in smartphone app advises participants on eliciting the provision of social support from their existing network related to one of the 3 target behaviors (daily weighing, active minutes, red food intake).

Core BWL Intervention + BCT 4 Message (Social Support)

Behavior Change Technique 5 Message (Social Comparison) BEHAVIORAL

Core BWL Intervention + Message in smartphone app systematically induces comparison of participants' behavioral performance with other participants, including general, upward (i.e., comparison to participants doing better: weighing more, engaging in more activity, staying within red food limits), and downward comparisons (to participants doing worse).

Core BWL Intervention + BCT 5 Message (Social Comparison)

Behavior Change Technique 6 Message (Social Reward) BEHAVIORAL

Core BWL Intervention + Message in smartphone app reinforces participants' effort or progress in performing one of the 3 target behaviors (daily weighing, active minutes, red food intake).

Core BWL Intervention + BCT 6 Message (Social Reward)

Behavior Change Technique 7 Message (Focus on Past Success) BEHAVIORAL

Core BWL Intervention + Message in smartphone app advises participants to think about or list previous successes related to performing one of the 3 target behaviors (daily weighing, active minutes, red food intake).

Core BWL Intervention + BCT 7 Message (Focus on Past Success)

Eligibility Criteria

• Age: 18 Years - 39 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• Body mass index (BMI) of 25 - 45 kg/m\^2 at baseline
• English-speaking, reading, and writing
• Own a smartphone with a data and text messaging plan

You may not qualify if:

• Type 1 diabetes or currently receiving medical treatment for Type 2 diabetes
• Report a heart condition, chest pain during periods of activity or rest, or loss of consciousness on the Physical Activity Readiness Questionnaire (PAR-Q; items 1-4).
• Other health problems which may influence the ability to walk for physical activity or be associated with unintentional weight change, including cancer treatment within the past 5 years or tuberculosis
• Lost 10 lbs. or more of body weight (and kept it off) in the last 6 months
• Past diagnosis of or receiving treatment for a clinically diagnosed eating disorder (anorexia nervosa or bulimia nervosa)
• Current symptoms of alcohol or substance dependence
• Currently pregnant, pregnant within the past 6 months, or planning to become pregnant within the next 6 months
• Untreated thyroid disease or any changes (type or dose) in thyroid medication in last 6 months
• Hospitalization for depression or other psychiatric disorder within the past 12 months
• History of psychotic disorder or bipolar disorder
• Currently participating in a weight loss, nutrition, or physical activity study or program or other study that would interfere with this study
• Currently using prescription medications with known effects on appetite or weight (e.g., oral steroids, weight loss medications), with the exception of individuals on a stable dose of Selective Serotonin Reuptake Inhibitors (SSRIs) for 3 months)
• Previous surgical procedure for weight loss or planned weight loss surgery in the next year
• Another member of the household is a participant or staff member on this trial
• Reason to suspect that the participant would not adhere to the study intervention

Sponsors & Collaborators

• University of North Carolina, Chapel Hill: lead
• National Heart, Lung, and Blood Institute (NHLBI): collaborator

Study Sites (1)

University of North Carolina at Chapel Hill

Chapel Hill, North Carolina, 27514, United States

Location

MeSH Terms

Conditions

Obesity; Overweight; Motor Activity

Interventions

Methods

Condition Hierarchy (Ancestors)

Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Behavior

Intervention Hierarchy (Ancestors)

Investigative Techniques

Results Point of Contact

• Title: Brooke Nezami, PhD
• Organization: University of North Carolina at Chapel Hill

bnezami@unc.edu

919-966-5852

Study Officials

• Carmina G. Valle, PhD, MPH

  Assistant Professor

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: Yes

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: DOUBLE
• Who Masked: INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: SEQUENTIAL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: This is a micro-randomized trial, a form of a sequential, factorial trial. At every time point, a participant is micro-randomized to receive or not receive an intervention message.

Study Record Dates

• First Submitted: November 14, 2022
• First Posted: November 22, 2022
• Study Start: August 25, 2023
• Primary Completion: January 5, 2025
• Study Completion: January 27, 2025
• Last Updated: February 17, 2026
• Results First Posted: January 27, 2026

Record last verified: 2025-01

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF
• Time Frame: beginning at 12 and continuing for 36 months following publication
• Access Criteria: Investigator has UNC PI-approved proposal, institutional IRB, IEC, or REB approval and an executed data use/sharing agreement with UNC

Locations

US (1)