Project Activate: Mindfulness and Acceptance Based Behavioral Treatment for Weight Loss (Activate)

March 10, 2026 updated by: Meghan Butryn, Drexel University

Mindfulness and Acceptance Based Behavioral Treatment for Weight Loss

Mindfulness and Acceptance based Behavioral Therapies (MABTs) are among the most promising behavioral approaches for obesity, with two recent large trials showing that they achieve better initial weight loss and/or better weight loss maintenance than does gold standard behavioral weight loss treatment (BT). However, results vary, potentially due to inconsistencies in how MABT components are utilized and emphasized. Optimizing MABTs using a typical approach, i.e., successive randomized controlled trials of various MABT packages, is slow and difficult. Multiphase Optimization Strategy (MOST) has been developed as a better method of optimizing treatment. Consistent with Phase I of MOST, we derived three MABT components from the theoretical literature. Evaluation of MABT components through a factorial design (MOST Phase II) will allow us to determine the independent and interacting efficacies of each MABT component, in addition to the identification of subsets of individuals most or least responsive to each component. Whereas mediational analyses have been inconclusive, the use of a factorial design will allow for a critical test of the main and interaction effects of individual MABT treatment components. The current study will use a full factorial design to identify the independent and combined effects of three core MABT components (Awareness, Acceptance, and Values Clarity) as additions to remotely delivered weight loss counseling. Moderators of treatment outcome (disinhibited eating, food cue susceptibility, emotional eating, delay discounting, and inhibitory control), and mediator/process variables implicated in MABTs (mindful eating, acceptance of food cues, mindfulness, body responsiveness, autonomous motivation, values clarity, hunger/satiety perceptions, and motivation and pleasure resulting from social functioning) will be assessed as well.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

276

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Pennsylvania
      • Philadelphia, Pennsylvania, United States, 19104
        • Drexel University Center for Weight, Eating and Lifestyle Science

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 70 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Individuals must be of overweight or obese BMI (27-50 kg/m2)
  • Individuals must be adults (aged 18-70)
  • Completion of a 3-day food diary
  • Completion of baseline assessment tasks
  • Willingness to lose weight, be physically active, and participate in-group sessions.
  • Participants must also provide consent for the research team to contact their personal physician if necessary to provide clearance or to consult about rapid weight gain.

Exclusion Criteria:

  • Inability to engage in physical activity (defined as walking a city block without stopping)
  • Medical or psychiatric condition that may pose a risk to the participant during intervention, cause a change in weight, or limit ability to comply with the program
  • Recently began or changed the dose of a medication that can cause significant change in weight
  • History of bariatric surgery; weight loss of > 5% in the previous 3 months
  • Currently pregnant or breastfeeding or planning to become pregnant
  • Planning to, or participating in, another weight loss treatment in the next 3 years.
  • Engaging in compensatory vomiting, other severe compensatory behaviors, or more than 12 of any compensatory behavior in the previous 3 months
  • Experiencing significant loss of control eating (9 or more binge episodes in the previous 3 months)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Factorial Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Standard Behavioral Weight Loss Treatment
Behavioral: Behavioral Treatment
Standard Behavioral Weight Loss Treatment (remotely delivered)
Experimental: Behavioral + Values
Behavioral: Behavioral Treatment
Standard Behavioral Weight Loss Treatment (remotely delivered)
Behavioral: Values
Integration of values clarification and awareness skills into Standard Behavioral Weight Loss Treatment (remotely delivered).
Experimental: Behavioral + Mindful Awareness
Behavioral: Behavioral Treatment
Standard Behavioral Weight Loss Treatment (remotely delivered)
Behavioral: Mindful Awareness
Integration of mindfulness and present-moment awareness skills into Standard Behavioral Weight Loss Treatment (remotely delivered).
Experimental: Behavioral + Values + Awareness
Behavioral: Behavioral Treatment
Standard Behavioral Weight Loss Treatment (remotely delivered)
Behavioral: Values
Integration of values clarification and awareness skills into Standard Behavioral Weight Loss Treatment (remotely delivered).
Behavioral: Mindful Awareness
Integration of mindfulness and present-moment awareness skills into Standard Behavioral Weight Loss Treatment (remotely delivered).
Experimental: Behavioral + Willingness
Behavioral: Behavioral Treatment
Standard Behavioral Weight Loss Treatment (remotely delivered)
Behavioral: Willingness
Integration of acceptance and willingness skills into Standard Behavioral Weight Loss Treatment (remotely delivered).
Experimental: Behavioral + Willingness + Values
Behavioral: Behavioral Treatment
Standard Behavioral Weight Loss Treatment (remotely delivered)
Behavioral: Values
Integration of values clarification and awareness skills into Standard Behavioral Weight Loss Treatment (remotely delivered).
Behavioral: Willingness
Integration of acceptance and willingness skills into Standard Behavioral Weight Loss Treatment (remotely delivered).
Experimental: Behavioral + Willingness + Awareness
Behavioral: Behavioral Treatment
Standard Behavioral Weight Loss Treatment (remotely delivered)
Behavioral: Mindful Awareness
Integration of mindfulness and present-moment awareness skills into Standard Behavioral Weight Loss Treatment (remotely delivered).
Behavioral: Willingness
Integration of acceptance and willingness skills into Standard Behavioral Weight Loss Treatment (remotely delivered).
Experimental: Behavioral + Willingness + Values + Awareness
Behavioral: Behavioral Treatment
Standard Behavioral Weight Loss Treatment (remotely delivered)
Behavioral: Values
Integration of values clarification and awareness skills into Standard Behavioral Weight Loss Treatment (remotely delivered).
Behavioral: Mindful Awareness
Integration of mindfulness and present-moment awareness skills into Standard Behavioral Weight Loss Treatment (remotely delivered).
Behavioral: Willingness
Integration of acceptance and willingness skills into Standard Behavioral Weight Loss Treatment (remotely delivered).

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Weight Change
Time Frame: Measured at baseline, mid-treatment (6 months), post-treatment (12 months), and at 6-, 12-, and 24-month follow-up (i.e., at 0, 6, 12, 18, 24 and 36 months).
Measured at home using a standardized weighing procedure. Participants will be weighed in lightweight clothes without shoes using a standardized bluetooth scale accurate to 0.1 kg.
Measured at baseline, mid-treatment (6 months), post-treatment (12 months), and at 6-, 12-, and 24-month follow-up (i.e., at 0, 6, 12, 18, 24 and 36 months).

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Dietary Intake
Time Frame: Measured at baseline, mid-treatment (6 months), post-treatment (12 months) (i.e., at 0, 6, and 12 months).
Dietary intake was recorded on the popular mobile application MyFitnessPal.
Measured at baseline, mid-treatment (6 months), post-treatment (12 months) (i.e., at 0, 6, and 12 months).
Physical Activity
Time Frame: Measured at baseline, mid-treatment (6 months), post-treatment (12 months), and at 6-, 12-, and 24-month follow-up (i.e., at 0, 6, 12, 18, 24 and 36 months).
Measured in minutes per week of moderate-to-vigorous physical activity (MVPA) using one wrist-worn activity tracker including Fitbit Charge 2, 3, 4, and 5.
Measured at baseline, mid-treatment (6 months), post-treatment (12 months), and at 6-, 12-, and 24-month follow-up (i.e., at 0, 6, 12, 18, 24 and 36 months).
Quality of Life Score
Time Frame: Measured at baseline, mid-treatment (6 months), post-treatment (12 months), and at 6-, 12-, and 24-month follow-up (i.e., at 0, 6, 12, 18, 24 and 36 months).
Measured using the Quality of Life Inventory (QOLI). The min and max values are 1 and 18. Higher scores mean a better outcome.
Measured at baseline, mid-treatment (6 months), post-treatment (12 months), and at 6-, 12-, and 24-month follow-up (i.e., at 0, 6, 12, 18, 24 and 36 months).

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Drexel University

Investigators

  • Principal Investigator: Evan M Forman, PhD, Drexel University Center for Weight, Eating and Lifestyle Science

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

August 15, 2019

Primary Completion (Actual)

November 7, 2024

Study Completion (Actual)

November 7, 2024

Study Registration Dates

First Submitted

February 25, 2020

First Submitted That Met QC Criteria

April 6, 2020

First Posted (Actual)

April 7, 2020

Study Record Updates

Last Update Posted (Actual)

March 11, 2026

Last Update Submitted That Met QC Criteria

March 10, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • R01DK119658 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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