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

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

Interventions

BEHAVIORAL

Core Behavioral Weight Loss (BWL) Intervention

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.

BEHAVIORAL

Behavior Change Technique 1 Message (Action Planning)

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).

BEHAVIORAL

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

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.

BEHAVIORAL

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

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).

BEHAVIORAL

Behavior Change Technique 4 Message (Social Support)

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).

BEHAVIORAL

Behavior Change Technique 5 Message (Social Comparison)

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).

BEHAVIORAL

Behavior Change Technique 6 Message (Social Reward)

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).

BEHAVIORAL

Behavior Change Technique 7 Message (Focus on Past Success)

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).

Sponsors & Collaborators

• National Heart, Lung, and Blood Institute (NHLBI)

  collaborator NIH

• University of North Carolina, Chapel Hill

  lead OTHER

Principal Investigators

• Carmina G. Valle, PhD, MPH · Assistant Professor

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

SEQUENTIAL

Eligibility

Min Age

18 Years

Max Age

39 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2023-08-25

Primary Completion

2025-01-05

Completion

2025-01-27

Countries

• United States

Study Locations