Testing Just-in-Time Adaptive Interventions (JITAIs) to Prevent Goal Disengagement in Response to Weight Regain (Momentum)

This trial will test the effectiveness of a weight loss maintenance intervention designed to help participants respond more adaptively to weight regain. Participants will be randomly assigned to one of two conditions. In one condition, participants will receive brief exercises (e.g., written reflections, videos) sent to through a smartphone app immediately after they regain weight or miss a weigh-in. These exercises will use mindfulness, acceptance, and self-compassion strategies to help participants stay motivated for their long term goals, even when weight regain feels demoralizing. In the comparison condition, participants will receive weekly reminders of standard weight control strategies strategies.

Study Overview

• Status: Recruiting
• Conditions: Overweight or Obesity
• Intervention / Treatment: Behavioral: JITAI Combined with psychological intervention; Behavioral: Active Control

• Study Type: Interventional
• Enrollment (Estimated): 120
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Charlotte Hagerman, PhD; Phone Number: 14109372035; Email: chagerman@ori.org

Study Locations

• United States
  • Oregon
    • Springfield, Oregon, United States, 97477
      • Recruiting
      • Oregon Research Institute Community and Evaluation Services
      • Contact: Charlotte Hagerman, PhD; Phone Number: 4109372035; Email: chagerman@ori.org

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Ages 18-70 years
• BMI of 25-50 kg/m2
• Current weight is 3% lower than their highest weight in the past 3 years
• Desire to maintain their weight or lose more
• Ability to engage in PA, as defined as being able to walk two full city blocks without stopping
• Smartphone and Internet access
• Successful completion of all enrollment procedures
• Ability to attend a workshop(s) on a Monday or Tuesday evening

Exclusion Criteria:

• History of bariatric surgery
• History of being diagnosed with an eating disorder
• Currently pregnant, breastfeeding, or planning to become pregnant in the next 24 months
• Enrolled in another formal weight loss/weight maintenance program
• Currently taking a GLP-1 medication.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: JITAI Condition; Participants in this condition will receive a 6-month weight loss maintenance intervention that uses mindfulness, acceptance, and self-compassion strategies to respond to weight regain.	Behavioral: JITAI Combined with psychological intervention; For six months, participants will receive a just-in-time adaptive interventions via a smartphone app immediately after they gain weight or they skip a weigh-in (according to a specific algorithm). Interventions will engage participants in mindfulness, acceptance, and self-compassion-based (MASC) strategies through different modalities (e.g., writing exercises, videos, audio reflections). They will take approximately 1-10 minutes. Participants will also attend an introductory workshop, during which they will receive the instructions weigh daily, learn the importance of quickly responding to weight regain, and be introduced to MASC strategies. They will also attend two booster workshops during the 6-month period.
Active Comparator: Active Control Condition; Participants in this condition will receive minimal intervention designed to reflect "usual care" for weight loss maintenance.	Behavioral: Active Control; For six months, participants will receive weekly, automated messages via a smartphone app with reminders of standard behavioral weight control principles. Participants will attend an introductory workshop, during which they will receive instructions to weigh daily and learn the importance of responding to weight regain.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
State negative affect	Through ecological assessment surveys, participants will respond to a single item measuring their current negative affect.	Whenever participants skip a weigh-in or regain weight during the 6 month study period
State shame	Through ecological assessment surveys, participants will respond to a single item measuring their current shame.	Whenever participants skip a weigh-in or regain weight during the 6 month study period
State Motivation	Through ecological assessment surveys, participants will respond to a single item measuring their current feelings of motivation.	Whenever participants skip a weigh-in or regain weight during the 6 month study period
State Self-Efficacy	Through ecological assessment surveys, participants will respond to a single item measuring their current self-efficacy.	Whenever participants skip a weigh-in or regain weight during the 6 month study period
Current confidence in the effectiveness of weight control behaviors	Through ecological assessment surveys, participants will respond to a single item measuring their current confidence in the effectiveness of weight control behaviors.	Whenever participants skip a weigh-in or regain weight during the 6 month study period
State self-compassion	Through ecological assessment surveys, participants will respond to a single item measuring their state self-compassion.	Whenever participants skip a weigh-in or regain weight during the 6 month study period
State mindfulness	Through ecological assessment surveys, participants will respond to a single item measuring their state mindfulness.	Whenever participants skip a weigh-in or regain weight during the 6 month study period
State acceptance	Through ecological assessment surveys, participants will respond to a single item measuring their state acceptance.	Whenever participants skip a weigh-in or regain weight during the 6 month study period
Self-serving interpretation of weight gain	Through ecological assessment surveys, participants will respond to a single item measuring their self-serving interpretation of the weight regain.	Whenever participants regain weight during the 6 month study period
Daily Calorie Tracking (Yes/No)	Whether participants log their calories (at least 800 calories) using a dietary tracking app that day (yes/no).	Whenever participants skip a weigh-in or regain weight during the 6 month study period
Daily MVPA	Minutes of moderate-to-vigorous physical activity they engage in that day, as tracked by their Fitbit band.	Whenever participants skip a weigh-in or regain weight during the 6 month study period
Likelihood of weighing in the following day	Likelihood that participants weigh themselves the following day on a wireless smart scale (yes/no).	Whenever participants skip a weigh-in or regain weight during the 6 month study period
Weight change	Using participants' weights from a wireless scale, we will calculate their percent weight change from the beginning to the end of the study period.	End of treatment (6 months after baseline)
Intervention acceptability	We will record the percent of participants who indicate that they are "satisfied" or "very satisfied" with the program on an anonymous survey that they complete during their individual interview.	End of treatment (6 months after baseline)
Calorie Tracking Frequency	The number of days that participants logged their calories (at least 800 calories) using a dietary tracking app during the study period.	6 months (duration of study period)
Average Weekly MVPA	Average total minutes of weekly moderate-to-vigorous physical activity, as tracked by their Fitbit band, during the study period.	6 months (duration of study period)
Frequency of Weighing In	Total number of days that participants weighed themselves on a wireless smart scale during the study period.	6 months (duration of study period)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mindfulness (Hypothesized intervention mediator)	Participants will self-report their mindfulness using the present moment awareness subscale of the Philadelphia Mindfulness Scale.	Mid-Treatment (3 months after baseline)
Acceptance (Hypothesized intervention mediator)	Participants will self-report their mindful acceptance using the acceptance subscale of the Philadelphia Mindfulness Scale.	Mid-Treatment (3 months after baseline)
Self-compassion (Hypothesized intervention mediator)	Participants will report their self-compassion using the State Self-Compassion Scale.	Mid-Treatment (3 months after baseline)

Collaborators and Investigators

• Sponsor: ORI Community and Evaluation Services

Study record dates

Study Major Dates

• Study Start (Estimated): July 1, 2026
• Primary Completion (Estimated): December 31, 2027
• Study Completion (Estimated): December 31, 2027

Study Registration Dates

• First Submitted: July 12, 2026
• First Submitted That Met QC Criteria: July 12, 2026
• First Posted (Actual): July 16, 2026

Study Record Updates

• Last Update Posted (Actual): July 16, 2026
• Last Update Submitted That Met QC Criteria: July 12, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: mindfulness; self-compassion; self-weighing; behavioral weight loss; weight regain; just-in-time adaptive interventions; acceptance-based behavioral treatments
• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Overweight; Obesity; Psychotherapy; Behavioral Disciplines and Activities; Psychosocial Intervention
• Other Study ID Numbers: K01HL172254 (U.S. NIH Grant/Contract)

Drug and device information, study documents

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