Adaptive Goals and Interventions for Lifestyle Enhancement

Not Applicable

Completed

• Conditions: Obesity
• Interventions: Behavioral: Core; Behavioral: Standard Diet Monitoring; Behavioral: Simplified Diet Monitoring; Behavioral: Adaptive Activity Goals (Daily); Behavioral: Adaptive Activity Goals (Weekly); Behavioral: Message Decision Points (Fixed); Behavioral: Message Decision Points (Adaptive); Behavioral: Message Decision Rules (Adaptive); Behavioral: Message Decision Rules (Standard); Behavioral: Message Choice (Yes); Behavioral: Message Choice (No)

• Registration Number: NCT04922216
• Lead Sponsor: University of North Carolina, Chapel Hill

Brief Summary

Mobile obesity interventions have the potential to reach a diverse population in need; however, while effective, have not resulted in weight losses obtained in in-person interventions. Newer digital approaches called Just-in-Time Adaptive Interventions (JITAI) that offer adaptive, personalized feedback 'when needed' and in 'real time' offer an opportunity to use digital health tools "just in time". This study seeks to identify the optimal components of a comprehensive weight loss JITAI that results in weight losses that meet or exceed those in existing remotely delivered interventions.

Detailed Description

Obesity has reached epidemic proportions in the United States and is recognized as a major cause of morbidity and mortality. Young adults (18-35 years) are at particularly high risk for weight gain and obesity. In-person behavioral interventions generally produce clinically significant weight losses; however, cost and access limit their potential to reduce obesity at a population level. Although web-based interventions that mimic the structure of weekly face-to-face treatment have proven a viable alternative treatment, weight losses are generally smaller than in-person treatment. Exclusively mobile treatments have been less effective, producing 1-3 kgs over 6 months. Newer digital intervention approaches called "Just-in-Time Adaptive Interventions" (JITAIs) promise to improve upon outcomes by offering adaptive, personalized feedback on behavior "when needed" in "real time," rather than on a fixed schedule. This "just-in-time," or JIT, approach is made possible by the emergence of low-cost and widely available digital health tools that allow for the collection of continually updated health data. However, few studies have used JIT approaches in remotely delivered, fully scalable weight loss interventions. Although JITAIs are a potentially transformative approach to delivering obesity interventions, a major obstacle in their development is efficient selection of components and systematic design of an optimized intervention package that produces clinically meaningful weight losses with a population-level strategy. To solve this problem, this trial will use the Multiphase Optimization Strategy (MOST), an engineering-inspired framework, and a highly efficient experimental design to identify which levels of 5 intervention components contribute meaningfully to change in weight over 6 months among young adults with overweight and obesity. All participants (n=608) will receive a core 6-month weight loss intervention that includes evidence-based lessons, behavioral skills training, and daily weighing. With the goal of determining if greater adaptation will lead to greater weight loss, participants will be randomized to standard versus more adaptive options of 5 additional intervention components: 1) diet monitoring approach (standard vs. simplified), 2) adaptive physical activity goals (weekly vs. daily), 3) decision points for message timing (fixed vs. adaptive), 4) decision rules for message content (standard vs. adaptive), and 5) message choice (no vs. yes). Candidate components have been carefully selected from empirical evidence, tested in prior studies conducted by the research team, or in a pilot micro-randomized trial conducted by the research team. Assessments will occur at 0, 3 and 6 months to accomplish the following specific aims: 1) Build an optimized JITAI consisting of the set of intervention components that yield the greatest improvement in weight change among young adults at 6 months; 2) Conduct mediation analyses to test the relationships between the intervention components and hypothesized proximal mediators (self-regulation, competence, relatedness, relevance, autonomy) and more distal behavioral mediators (dietary intake, physical activity, and daily self-weighting); and 3) Conduct exploratory analyses of program engagement.

Study Timeline

• Study First Submitted: 2021-06-04
• Study First Submitted QC: 2021-06-04
• Study First Posted: 2021-06-10
• Study Start: 2022-04-28
• Status Verified: 2023-10
• Primary Completion: 2024-06-20
• Study Completion: 2024-07-01
• Last Update Submitted: 2024-10-11
• Last Update Posted: 2024-10-16

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 624

Inclusion Criteria

• body mass index (BMI) of 25-45 kg/m^2
• English-speaking and writing
• own a smartphone with a data and text messaging plan
• reporting engaging in less than 210 minutes/week of moderate-to-vigorous intensity activity
• willing to be randomized to any levels of the factors

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Exclusion Criteria

• Type 1 diabetes or currently receiving medical treatment for Type 2 diabetes
• 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
• 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)
• Lost 10 or more pounds (and kept it off) in the last 6 months
• Currently taking weight loss medications
• Report a past diagnosis of or current treatment for a DSM-V (Diagnostic and Statistical Manual 5) eating disorder (anorexia nervosa or bulimia nervosa)
• Currently pregnant, pregnant within the past 6 months, or planning to become pregnant within the next 6 months
• Hospitalization for depression or other psychiatric disorder within the past 12 months
• History of psychotic disorder or bipolar disorder
• Another member of the household is a participant or staff member on this trial
• Currently participating in a weight loss, nutrition or physical activity study or program or other study that would interfere with this study

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: FACTORIAL

Arm && Interventions

Group	Intervention	Description
Condition 1	Message Decision Points (Fixed)	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Standard Content + No Choice
Condition 2	Core	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Standard Content + Choice
Condition 2	Message Decision Points (Fixed)	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Standard Content + Choice
Condition 3	Adaptive Activity Goals (Daily)	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Adaptive Content + No Choice
Condition 4	Message Decision Rules (Adaptive)	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 6	Message Decision Points (Adaptive)	Core + Standard Diet Monitoring + Daily Activity Goal + Adaptive Timing + Standard Content + Choice
Condition 7	Standard Diet Monitoring	Core+ Standard Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 1	Message Decision Rules (Standard)	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Standard Content + No Choice
Condition 2	Message Choice (Yes)	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Standard Content + Choice
Condition 3	Core	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Adaptive Content + No Choice
Condition 5	Message Choice (No)	Core+Standard Diet Monitoring+Daily Activity Goal+Adaptive Timing+Standard Content+No Choice
Condition 1	Standard Diet Monitoring	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Standard Content + No Choice
Condition 1	Message Choice (No)	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Standard Content + No Choice
Condition 2	Message Decision Rules (Standard)	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Standard Content + Choice
Condition 3	Message Decision Points (Fixed)	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Adaptive Content + No Choice
Condition 3	Message Decision Rules (Adaptive)	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Adaptive Content + No Choice
Condition 3	Message Choice (No)	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Adaptive Content + No Choice
Condition 7	Message Decision Points (Adaptive)	Core+ Standard Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 1	Core	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Standard Content + No Choice
Condition 2	Standard Diet Monitoring	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Standard Content + Choice
Condition 2	Adaptive Activity Goals (Daily)	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Standard Content + Choice
Condition 3	Standard Diet Monitoring	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Adaptive Content + No Choice
Condition 4	Core	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 4	Adaptive Activity Goals (Daily)	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 1	Adaptive Activity Goals (Daily)	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Standard Content + No Choice
Condition 4	Standard Diet Monitoring	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 4	Message Choice (Yes)	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 6	Message Decision Rules (Standard)	Core + Standard Diet Monitoring + Daily Activity Goal + Adaptive Timing + Standard Content + Choice
Condition 6	Message Choice (Yes)	Core + Standard Diet Monitoring + Daily Activity Goal + Adaptive Timing + Standard Content + Choice
Condition 8	Core	Core + Standard Diet Monitoring + Daily Activity Goal + Adaptive Timing + Adaptive Content + Choice
Condition 10	Standard Diet Monitoring	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Standard Content + Choice
Condition 5	Core	Core+Standard Diet Monitoring+Daily Activity Goal+Adaptive Timing+Standard Content+No Choice
Condition 5	Message Decision Rules (Standard)	Core+Standard Diet Monitoring+Daily Activity Goal+Adaptive Timing+Standard Content+No Choice
Condition 6	Standard Diet Monitoring	Core + Standard Diet Monitoring + Daily Activity Goal + Adaptive Timing + Standard Content + Choice
Condition 8	Adaptive Activity Goals (Daily)	Core + Standard Diet Monitoring + Daily Activity Goal + Adaptive Timing + Adaptive Content + Choice
Condition 4	Message Decision Points (Fixed)	Core + Standard Diet Monitoring + Daily Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 5	Standard Diet Monitoring	Core+Standard Diet Monitoring+Daily Activity Goal+Adaptive Timing+Standard Content+No Choice
Condition 5	Adaptive Activity Goals (Daily)	Core+Standard Diet Monitoring+Daily Activity Goal+Adaptive Timing+Standard Content+No Choice
Condition 5	Message Decision Points (Adaptive)	Core+Standard Diet Monitoring+Daily Activity Goal+Adaptive Timing+Standard Content+No Choice
Condition 6	Core	Core + Standard Diet Monitoring + Daily Activity Goal + Adaptive Timing + Standard Content + Choice
Condition 7	Core	Core+ Standard Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 8	Message Decision Rules (Adaptive)	Core + Standard Diet Monitoring + Daily Activity Goal + Adaptive Timing + Adaptive Content + Choice
Condition 9	Adaptive Activity Goals (Weekly)	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Standard Content + No Choice
Condition 9	Message Decision Rules (Standard)	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Standard Content + No Choice
Condition 10	Core	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Standard Content + Choice
Condition 11	Core	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Adaptive Content + No Choice
Condition 11	Standard Diet Monitoring	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Adaptive Content + No Choice
Condition 7	Adaptive Activity Goals (Daily)	Core+ Standard Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 10	Message Decision Points (Fixed)	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Standard Content + Choice
Condition 6	Adaptive Activity Goals (Daily)	Core + Standard Diet Monitoring + Daily Activity Goal + Adaptive Timing + Standard Content + Choice
Condition 7	Message Decision Rules (Adaptive)	Core+ Standard Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 7	Message Choice (No)	Core+ Standard Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 8	Standard Diet Monitoring	Core + Standard Diet Monitoring + Daily Activity Goal + Adaptive Timing + Adaptive Content + Choice
Condition 9	Message Decision Points (Fixed)	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Standard Content + No Choice
Condition 10	Message Choice (Yes)	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Standard Content + Choice
Condition 11	Message Decision Rules (Adaptive)	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Adaptive Content + No Choice
Condition 13	Message Decision Points (Adaptive)	Core+Standard Diet Monitoring+Weekly Activity Goal+Adaptive Timing+Standard Content+No Choice
Condition 14	Standard Diet Monitoring	Core + Standard Diet Monitoring + Weekly Activity Goal + Adaptive Timing + Standard Content + Choice
Condition 8	Message Decision Points (Adaptive)	Core + Standard Diet Monitoring + Daily Activity Goal + Adaptive Timing + Adaptive Content + Choice
Condition 8	Message Choice (Yes)	Core + Standard Diet Monitoring + Daily Activity Goal + Adaptive Timing + Adaptive Content + Choice
Condition 9	Standard Diet Monitoring	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Standard Content + No Choice
Condition 9	Message Choice (No)	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Standard Content + No Choice
Condition 10	Adaptive Activity Goals (Weekly)	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Standard Content + Choice
Condition 11	Adaptive Activity Goals (Weekly)	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Adaptive Content + No Choice
Condition 11	Message Decision Points (Fixed)	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Adaptive Content + No Choice
Condition 13	Standard Diet Monitoring	Core+Standard Diet Monitoring+Weekly Activity Goal+Adaptive Timing+Standard Content+No Choice
Condition 14	Core	Core + Standard Diet Monitoring + Weekly Activity Goal + Adaptive Timing + Standard Content + Choice
Condition 9	Core	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Standard Content + No Choice
Condition 10	Message Decision Rules (Standard)	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Standard Content + Choice
Condition 12	Core	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 12	Adaptive Activity Goals (Weekly)	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 12	Message Decision Points (Fixed)	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 13	Core	Core+Standard Diet Monitoring+Weekly Activity Goal+Adaptive Timing+Standard Content+No Choice
Condition 13	Adaptive Activity Goals (Weekly)	Core+Standard Diet Monitoring+Weekly Activity Goal+Adaptive Timing+Standard Content+No Choice
Condition 13	Message Decision Rules (Standard)	Core+Standard Diet Monitoring+Weekly Activity Goal+Adaptive Timing+Standard Content+No Choice
Condition 15	Core	Core + Standard Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 15	Standard Diet Monitoring	Core + Standard Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 15	Adaptive Activity Goals (Weekly)	Core + Standard Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 11	Message Choice (No)	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Adaptive Content + No Choice
Condition 12	Standard Diet Monitoring	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 12	Message Decision Rules (Adaptive)	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 12	Message Choice (Yes)	Core + Standard Diet Monitoring + Weekly Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 13	Message Choice (No)	Core+Standard Diet Monitoring+Weekly Activity Goal+Adaptive Timing+Standard Content+No Choice
Condition 14	Adaptive Activity Goals (Weekly)	Core + Standard Diet Monitoring + Weekly Activity Goal + Adaptive Timing + Standard Content + Choice
Condition 14	Message Decision Points (Adaptive)	Core + Standard Diet Monitoring + Weekly Activity Goal + Adaptive Timing + Standard Content + Choice
Condition 14	Message Decision Rules (Standard)	Core + Standard Diet Monitoring + Weekly Activity Goal + Adaptive Timing + Standard Content + Choice
Condition 15	Message Decision Points (Adaptive)	Core + Standard Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 16	Standard Diet Monitoring	Core + Standard Diet Monitoring + Weekly Activity Goal + Adaptive Timing + Adaptive Content + Choice
Condition 17	Message Decision Rules (Standard)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Fixed Timing+ Standard Content+ No Choice
Condition 18	Message Decision Points (Fixed)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Fixed Timing+ Standard Content+ Choice
Condition 19	Adaptive Activity Goals (Daily)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Fixed Timing+ Adaptive Content+ No Choice
Condition 14	Message Choice (Yes)	Core + Standard Diet Monitoring + Weekly Activity Goal + Adaptive Timing + Standard Content + Choice
Condition 15	Message Choice (No)	Core + Standard Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 16	Message Decision Points (Adaptive)	Core + Standard Diet Monitoring + Weekly Activity Goal + Adaptive Timing + Adaptive Content + Choice
Condition 18	Message Choice (Yes)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Fixed Timing+ Standard Content+ Choice
Condition 19	Core	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Fixed Timing+ Adaptive Content+ No Choice
Condition 19	Message Choice (No)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Fixed Timing+ Adaptive Content+ No Choice
Condition 20	Message Choice (Yes)	Core + Simplified Diet Monitoring + Daily Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 21	Simplified Diet Monitoring	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Standard Content+ No Choice
Condition 21	Message Decision Points (Adaptive)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Standard Content+ No Choice
Condition 22	Message Decision Points (Adaptive)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Standard Content+ Choice
Condition 22	Message Decision Rules (Standard)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Standard Content+ Choice
Condition 23	Simplified Diet Monitoring	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 27	Core	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Fixed Timing+ Adaptive Content+ No Choice
Condition 27	Adaptive Activity Goals (Weekly)	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Fixed Timing+ Adaptive Content+ No Choice
Condition 24	Message Decision Rules (Adaptive)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Adaptive Content+ Choice
Condition 22	Simplified Diet Monitoring	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Standard Content+ Choice
Condition 24	Message Choice (Yes)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Adaptive Content+ Choice
Condition 15	Message Decision Rules (Adaptive)	Core + Standard Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 16	Core	Core + Standard Diet Monitoring + Weekly Activity Goal + Adaptive Timing + Adaptive Content + Choice
Condition 16	Adaptive Activity Goals (Weekly)	Core + Standard Diet Monitoring + Weekly Activity Goal + Adaptive Timing + Adaptive Content + Choice
Condition 17	Adaptive Activity Goals (Daily)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Fixed Timing+ Standard Content+ No Choice
Condition 17	Message Decision Points (Fixed)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Fixed Timing+ Standard Content+ No Choice
Condition 20	Simplified Diet Monitoring	Core + Simplified Diet Monitoring + Daily Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 23	Message Decision Rules (Adaptive)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 24	Core	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Adaptive Content+ Choice
Condition 24	Simplified Diet Monitoring	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Adaptive Content+ Choice
Condition 24	Message Decision Points (Adaptive)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Adaptive Content+ Choice
Condition 16	Message Decision Rules (Adaptive)	Core + Standard Diet Monitoring + Weekly Activity Goal + Adaptive Timing + Adaptive Content + Choice
Condition 16	Message Choice (Yes)	Core + Standard Diet Monitoring + Weekly Activity Goal + Adaptive Timing + Adaptive Content + Choice
Condition 17	Core	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Fixed Timing+ Standard Content+ No Choice
Condition 17	Simplified Diet Monitoring	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Fixed Timing+ Standard Content+ No Choice
Condition 17	Message Choice (No)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Fixed Timing+ Standard Content+ No Choice
Condition 18	Simplified Diet Monitoring	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Fixed Timing+ Standard Content+ Choice
Condition 19	Message Decision Rules (Adaptive)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Fixed Timing+ Adaptive Content+ No Choice
Condition 20	Message Decision Points (Fixed)	Core + Simplified Diet Monitoring + Daily Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 21	Message Decision Rules (Standard)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Standard Content+ No Choice
Condition 21	Message Choice (No)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Standard Content+ No Choice
Condition 23	Core	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 23	Message Decision Points (Adaptive)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 23	Message Choice (No)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 27	Message Decision Points (Fixed)	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Fixed Timing+ Adaptive Content+ No Choice
Condition 18	Core	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Fixed Timing+ Standard Content+ Choice
Condition 18	Adaptive Activity Goals (Daily)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Fixed Timing+ Standard Content+ Choice
Condition 18	Message Decision Rules (Standard)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Fixed Timing+ Standard Content+ Choice
Condition 19	Simplified Diet Monitoring	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Fixed Timing+ Adaptive Content+ No Choice
Condition 20	Core	Core + Simplified Diet Monitoring + Daily Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 20	Adaptive Activity Goals (Daily)	Core + Simplified Diet Monitoring + Daily Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 25	Core	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Fixed Timing+ Standard Content+ No Choice
Condition 25	Adaptive Activity Goals (Weekly)	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Fixed Timing+ Standard Content+ No Choice
Condition 25	Message Decision Points (Fixed)	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Fixed Timing+ Standard Content+ No Choice
Condition 28	Message Decision Rules (Adaptive)	Core + Simplified Diet Monitoring + Weekly Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 26	Adaptive Activity Goals (Weekly)	Core + Simplified Diet Monitoring + Weekly Activity Goal + Fixed Timing + Standard Content + Choice
Condition 22	Adaptive Activity Goals (Daily)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Standard Content+ Choice
Condition 22	Message Choice (Yes)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Standard Content+ Choice
Condition 19	Message Decision Points (Fixed)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Fixed Timing+ Adaptive Content+ No Choice
Condition 20	Message Decision Rules (Adaptive)	Core + Simplified Diet Monitoring + Daily Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 21	Core	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Standard Content+ No Choice
Condition 21	Adaptive Activity Goals (Daily)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Standard Content+ No Choice
Condition 22	Core	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Standard Content+ Choice
Condition 23	Adaptive Activity Goals (Daily)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 24	Adaptive Activity Goals (Daily)	Core+ Simplified Diet Monitoring+ Daily Activity Goal+ Adaptive Timing+ Adaptive Content+ Choice
Condition 28	Simplified Diet Monitoring	Core + Simplified Diet Monitoring + Weekly Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 28	Message Choice (Yes)	Core + Simplified Diet Monitoring + Weekly Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 25	Simplified Diet Monitoring	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Fixed Timing+ Standard Content+ No Choice
Condition 25	Message Decision Rules (Standard)	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Fixed Timing+ Standard Content+ No Choice
Condition 25	Message Choice (No)	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Fixed Timing+ Standard Content+ No Choice
Condition 29	Message Decision Points (Adaptive)	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Standard Content+ No Choice
Condition 26	Core	Core + Simplified Diet Monitoring + Weekly Activity Goal + Fixed Timing + Standard Content + Choice
Condition 26	Simplified Diet Monitoring	Core + Simplified Diet Monitoring + Weekly Activity Goal + Fixed Timing + Standard Content + Choice
Condition 26	Message Decision Points (Fixed)	Core + Simplified Diet Monitoring + Weekly Activity Goal + Fixed Timing + Standard Content + Choice
Condition 26	Message Choice (Yes)	Core + Simplified Diet Monitoring + Weekly Activity Goal + Fixed Timing + Standard Content + Choice
Condition 27	Simplified Diet Monitoring	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Fixed Timing+ Adaptive Content+ No Choice
Condition 27	Message Decision Rules (Adaptive)	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Fixed Timing+ Adaptive Content+ No Choice
Condition 28	Core	Core + Simplified Diet Monitoring + Weekly Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 29	Core	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Standard Content+ No Choice
Condition 29	Adaptive Activity Goals (Weekly)	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Standard Content+ No Choice
Condition 26	Message Decision Rules (Standard)	Core + Simplified Diet Monitoring + Weekly Activity Goal + Fixed Timing + Standard Content + Choice
Condition 27	Message Choice (No)	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Fixed Timing+ Adaptive Content+ No Choice
Condition 28	Adaptive Activity Goals (Weekly)	Core + Simplified Diet Monitoring + Weekly Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 28	Message Decision Points (Fixed)	Core + Simplified Diet Monitoring + Weekly Activity Goal + Fixed Timing + Adaptive Content + Choice
Condition 29	Simplified Diet Monitoring	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Standard Content+ No Choice
Condition 29	Message Choice (No)	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Standard Content+ No Choice
Condition 30	Simplified Diet Monitoring	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Standard Content+ Choice
Condition 30	Message Decision Rules (Standard)	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Standard Content+ Choice
Condition 31	Message Choice (No)	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 32	Adaptive Activity Goals (Weekly)	Core + Simplified Diet Monitoring + Weekly Activity Goal + Adaptive Timing + Adaptive Content+Choice
Condition 29	Message Decision Rules (Standard)	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Standard Content+ No Choice
Condition 32	Simplified Diet Monitoring	Core + Simplified Diet Monitoring + Weekly Activity Goal + Adaptive Timing + Adaptive Content+Choice
Condition 30	Core	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Standard Content+ Choice
Condition 30	Adaptive Activity Goals (Weekly)	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Standard Content+ Choice
Condition 30	Message Decision Points (Adaptive)	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Standard Content+ Choice
Condition 30	Message Choice (Yes)	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Standard Content+ Choice
Condition 32	Message Decision Points (Adaptive)	Core + Simplified Diet Monitoring + Weekly Activity Goal + Adaptive Timing + Adaptive Content+Choice
Condition 32	Message Decision Rules (Adaptive)	Core + Simplified Diet Monitoring + Weekly Activity Goal + Adaptive Timing + Adaptive Content+Choice
Condition 32	Message Choice (Yes)	Core + Simplified Diet Monitoring + Weekly Activity Goal + Adaptive Timing + Adaptive Content+Choice
Condition 31	Core	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 31	Simplified Diet Monitoring	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 31	Message Decision Rules (Adaptive)	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 32	Core	Core + Simplified Diet Monitoring + Weekly Activity Goal + Adaptive Timing + Adaptive Content+Choice
Condition 31	Adaptive Activity Goals (Weekly)	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice
Condition 31	Message Decision Points (Adaptive)	Core+ Simplified Diet Monitoring+ Weekly Activity Goal+ Adaptive Timing+ Adaptive Content+ No Choice

Primary Outcome Measures

Name	Time	Method
Weight	Baseline, 6 months	Absolute weight change from baseline to 6 months. Weight will be objectively measured on a digital scale in the participant's home.

Secondary Outcome Measures

Name	Time	Method
Diet self-monitoring adherence	Baseline to 6 months (daily)	Number of days of complete dietary tracking summed over the 6-month study period.
Achievement of 5% weight loss	Baseline to 6 months	Percent change in body weight will be calculated (6 month weight - baseline weight/100) and determined to be at or above 5% indicating a clinically significant change.
Weight	Baseline, 3 months	Absolute weight change from baseline to 3 months. Weight will be objectively measured on a digital scale in the participant's home.
Diet	Baseline, 6 months	Change in daily caloric intake from baseline to 3 and 6 months as measured using the self-administered National Cancer Institute's Automated Self- Administered 24-hour Recall (ASA-24), a 24-hour recall that is self-administered on a week day and a weekend day at each timepoint.
Physical Activity	Baseline,3 months, 6 months	Change in physical activity from baseline to 3 and 6 months as measured using the Paffenbarger Physical Activity Questionnaire (PPAQ). The PPAQ assesses amount of planned and lifestyle associated physical activity performed during a typical week. The PPAQ consists of three components: (1) stair climbing, (2) walking, and (3) sports and recreation. Participants report the frequency and duration of physical activity in the past week. Scoring yields energy expenditure from physical activity per week (kcal/kg/week). Higher scores translate into greater energy expenditure per week (i.e.,better outcome). Range is 0 - no theoretical maximum.
Sedentary Behavior score	Baseline, 3 months, 6 months	Change in sedentary behavior from baseline to 3 and 6 months as measured using the 12- item Sedentary Behavior Questionnaire which asks respondents to indicate the number of hours they spend on a typical weekday and a typical weekend day doing each of six activities. The scale ranges from "none" to "6 or more hours" for each item. Higher values on the Sedentary Behavior Questionnaire indicate greater amount of time spent in sedentary behavior. Range is 0 to 24 hours.
Perceived Message Relevance score	Baseline, 3 months, 6 months	Change in perceived message relevance from baseline to 3 and 6 months as measured using two items used in our previous work and adapted from previous studies of tailored messages. Participants were asked to rate how strongly they disagree or agree with the statements about messages being "written personally for me" and "applied to my life." Responses are on a 5-point scale from 1 (strongly disagree) to 5 (strongly agree). Higher values indicate that a participant perceives the messages received in the program are more relevant to them.
Competence for Diet and Physical Activity score	Baseline, 3 months, 6 months	Change in perceived competence from baseline to 3 and 6 months as measured using the The Perceived Competence for Scale. The Scale measures perceived competence for diet (4 items) and physical activity (4 items). Items are rated on a 7-point Likert scale (1 = not at all true, 7 = very true), and include items such as "I feel confident in my ability to maintain a healthy diet." Scores are summed for the items in the subscale (diet and physical activity) and the range for each subscale is 4 - 28. Greater values indicate higher levels of perceived competence for engaging in positive diet and physical activity behaviors. Scores are summed for the items in the subscale (diet and physical activity)
Autonomy Support score	Baseline, 3 months, 6 months	Change in autonomy support from baseline to 3 and 6 months. Items are adapted from the Health Care Climate Questionnaire, which is a measure of how the participant perceives support from a healthcare provider, to measure autonomy support from the program. The scale includes 15 items rated on a scale of 1 (strongly disagree) to 7 (strongly agree) (e.g., "I feel that \[the program\] has provided me choices and options.") Scores are calculated by averaging the individual item scores (with item 13 reverse-scored). Higher average scores represent a higher level of perceived autonomy support.
Relatedness score	Baseline, 3 months, 6 months	Change in relatedness from baseline to 3 and 6 months as measured with 3 items adapted from the 8-item Relatedness subscale of the Basic Need Satisfaction at Work Scale. Examples include "The messages demonstrate caring about me as a person" and are scored on a Likert scale from 1 (strongly disagree) to 7 (strongly agree). Responses are averaged with a range of 1 to 7. Higher scores indicate a higher level of perceived relatedness from the intervention messages.
Weighing adherence	Baseline to 6 months (daily)	Number of days of self-weighing over the 6 month period.
Treatment Self-Regulation score	Baseline, 3 months, 6 months	Change in treatment self-regulation from baseline to 3 and 6 months as measured using the Treatment Self-Regulation Questionnaire (TSRQ). The TSRQ assesses autonomous and controlled motivation for making changes in diet (15 items) and physical activity (15 items). Examples item: "Because I feel that I want to take responsibility for my own health" answered on a scale of 1 (not at all true) to 7 (very true)." Calculating the scores for the sub-scales will consist of averaging the items on that subscale. They are: Autonomous Regulation: 2, 3, 7, 10, 13, 16, 18, 19 Controlled Regulation: 1, 4, 5, 6, 8, 9, 11, 12, 14, 15, 17. Responses to the items within the subscale are averaged with the range of scores being 1 to 7. Higher values on each subscale indicate greater levels of that type of motivation.
Physical activity self-monitoring adherence	Baseline to 6 months (daily)	Number of days of physical activity tracking over the 6 month period as measured by Fitbit tracker wear.

Trial Locations

Locations (1)

University of North Carolina at Chapel Hill; 🇺🇸 Chapel Hill, North Carolina, United States