NCT04337619

Brief Summary

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.

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
276

participants targeted

Target at P75+ for not_applicable obesity

Timeline
Completed

Started Aug 2019

Longer than P75 for not_applicable obesity

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Start

First participant enrolled

August 15, 2019

Completed
6 months until next milestone

First Submitted

Initial submission to the registry

February 25, 2020

Completed
1 month until next milestone

First Posted

Study publicly available on registry

April 7, 2020

Completed
4.6 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

November 7, 2024

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

November 7, 2024

Completed
1.3 years until next milestone

Results Posted

Study results publicly available

March 11, 2026

Completed
Last Updated

March 11, 2026

Status Verified

March 1, 2026

Enrollment Period

5.2 years

First QC Date

February 25, 2020

Results QC Date

January 20, 2026

Last Update Submit

March 10, 2026

Conditions

Keywords

ObesityWeight LossBehavioral treatmentAcceptance-based behavioral weight loss treatmentAcceptance and Commitment TherapyMultiphase Optimization Strategy

Outcome Measures

Primary Outcomes (1)

  • Weight Change

    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 Outcomes (3)

  • Dietary Intake

    Measured at baseline, mid-treatment (6 months), post-treatment (12 months) (i.e., at 0, 6, and 12 months).

  • Physical Activity

    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

    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).

Study Arms (8)

Standard Behavioral Weight Loss Treatment

EXPERIMENTAL
Behavioral: Behavioral Treatment

Behavioral + Willingness

EXPERIMENTAL
Behavioral: Behavioral TreatmentBehavioral: Willingness

Behavioral + Values

EXPERIMENTAL
Behavioral: Behavioral TreatmentBehavioral: Values

Behavioral + Mindful Awareness

EXPERIMENTAL
Behavioral: Behavioral TreatmentBehavioral: Mindful Awareness

Behavioral + Willingness + Values

EXPERIMENTAL
Behavioral: Behavioral TreatmentBehavioral: WillingnessBehavioral: Values

Behavioral + Willingness + Awareness

EXPERIMENTAL
Behavioral: Behavioral TreatmentBehavioral: WillingnessBehavioral: Mindful Awareness

Behavioral + Values + Awareness

EXPERIMENTAL
Behavioral: Behavioral TreatmentBehavioral: ValuesBehavioral: Mindful Awareness

Behavioral + Willingness + Values + Awareness

EXPERIMENTAL
Behavioral: Behavioral TreatmentBehavioral: WillingnessBehavioral: ValuesBehavioral: Mindful Awareness

Interventions

WillingnessBEHAVIORAL

Integration of acceptance and willingness skills into Standard Behavioral Weight Loss Treatment (remotely delivered).

Behavioral + WillingnessBehavioral + Willingness + AwarenessBehavioral + Willingness + ValuesBehavioral + Willingness + Values + Awareness

Standard Behavioral Weight Loss Treatment (remotely delivered)

Behavioral + Mindful AwarenessBehavioral + ValuesBehavioral + Values + AwarenessBehavioral + WillingnessBehavioral + Willingness + AwarenessBehavioral + Willingness + ValuesBehavioral + Willingness + Values + AwarenessStandard Behavioral Weight Loss Treatment
ValuesBEHAVIORAL

Integration of values clarification and awareness skills into Standard Behavioral Weight Loss Treatment (remotely delivered).

Behavioral + ValuesBehavioral + Values + AwarenessBehavioral + Willingness + ValuesBehavioral + Willingness + Values + Awareness

Integration of mindfulness and present-moment awareness skills into Standard Behavioral Weight Loss Treatment (remotely delivered).

Behavioral + Mindful AwarenessBehavioral + Values + AwarenessBehavioral + Willingness + AwarenessBehavioral + Willingness + Values + Awareness

Eligibility Criteria

Age18 Years - 70 Years
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • 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.

You may not qualify if:

  • 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)

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Drexel University Center for Weight, Eating and Lifestyle Science

Philadelphia, Pennsylvania, 19104, United States

Location

Related Publications (3)

  • Crochiere RJ, Fitzgerald DT, Butryn ML, Zhang F, Beaulieu K, Maher JP, Huang Z, Cong C, Forman EM. Moderators of the relation between physical activity and subsequent energy intake among behavioral weight loss participants. Health Psychol. 2026 Mar 5. doi: 10.1037/hea0001597. Online ahead of print.

  • Chabria R, Hagerman CJ, Crane N, Ehmann M, Knudsen FM, Brown KL, Forman E, Butryn ML. Racial disparities in the efficacy of traditional versus acceptance-based behavioral weight loss. Health Psychol. 2026 Feb;45(2):197-205. doi: 10.1037/hea0001537. Epub 2025 Jul 24.

  • Crochiere RJ, Butryn ML, Zhang F, Beaulieu K, Maher JP, Huang Z, Cong C, Forman EM. Intraday relations between physical activity and energy intake among behavioral weight loss participants. Health Psychol. 2024 May;43(5):376-387. doi: 10.1037/hea0001358. Epub 2024 Jan 8.

MeSH Terms

Conditions

ObesityWeight Loss

Interventions

Behavior Therapy

Condition Hierarchy (Ancestors)

OverweightOvernutritionNutrition DisordersNutritional and Metabolic DiseasesBody WeightSigns and SymptomsPathological Conditions, Signs and SymptomsBody Weight Changes

Intervention Hierarchy (Ancestors)

PsychotherapyBehavioral Disciplines and Activities

Limitations and Caveats

Average daily calorie intake was not analyzed as an outcome or included in the imputation model because this measure is expected to be strongly biased by participants' adherence to food tracking and inaccuracies in calorie estimation (Butryn et al., 2020; Mixon and Davis, 2020).

Results Point of Contact

Title
Fengqing Zhang
Organization
Drexel University

Study Officials

  • Evan M Forman, PhD

    Drexel University Center for Weight, Eating and Lifestyle Science

    PRINCIPAL INVESTIGATOR

Publication Agreements

PI is Sponsor Employee
Yes

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
DOUBLE
Who Masked
PARTICIPANT, OUTCOMES ASSESSOR
Purpose
TREATMENT
Intervention Model
FACTORIAL
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Professor

Study Record Dates

First Submitted

February 25, 2020

First Posted

April 7, 2020

Study Start

August 15, 2019

Primary Completion

November 7, 2024

Study Completion

November 7, 2024

Last Updated

March 11, 2026

Results First Posted

March 11, 2026

Record last verified: 2026-03

Data Sharing

IPD Sharing
Will not share

Locations