Dietary Fiber: Is it the Missing Link in Achieving Long Term Behavior Change?

September 23, 2025 updated by: Oklahoma State University
The overall objective of this three-arm randomized controlled trial is to compare a dietary fiber-focused behavioral intervention to standard weight loss education for improving eating-related behavior and cognition, weight, and metabolic markers of chronic disease risk in a population of adults with obesity.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
63

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Locations

  • United States
    • Oklahoma
      • Stillwater, Oklahoma, United States, 74078
        • Oklahoma State University

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • 18-65 years of age
  • Dietary fiber intake ≤25 grams/day
  • Self-reported BMI ≥30 kg/m2
  • Willingness to attend in-person education sessions
  • Willingness to avoid taking supplemental digestive aids (e.g., alpha-galactosidase (Beano®),
  • Willingness to provide informed consent.

Exclusion Criteria:

  • Metabolic, digestive, or allergic conditions or reactions that preclude consumption of whole food or food groups (e.g., irritable bowel syndrome, diverticulosis)
  • History of gastric bypass surgery
  • Currently taking glucagon like glucagon-like peptide-1 (GLP-1) Receptor Agonists
  • Self-reported history of a diagnosed eating disorder
  • Chronic disease (other than obesity)
  • Pregnancy or lactation
  • Use of tobacco or electronic smoking products
  • Taking a pre-, pro-, or syn-biotic supplement
  • Enrollment in another weight loss or diet intervention

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: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Fiber Intervention
Individuals in this arm will be given instruction on how to increase fiber intake,
Behavioral: Fiber Intervention
Group education and phone-based motivational interviewing to gradually increase dietary fiber consumption to 30-35 grams per day.
Active Comparator: Standard Weight Loss Education
Individuals in this arm will be given standard weight loss education
Behavioral: Standard Weight Loss Education
Group education and phone-based motivational interviewing to promote current evidence-based behaviors to promote weight loss via achieving a negative energy balance.
Experimental: Fiber Intervention + Standard Weight Loss Education
Individuals in this arm will be given education on both fiber and standard weight loss
Behavioral: Standard Weight Loss Education
Group education and phone-based motivational interviewing to promote current evidence-based behaviors to promote weight loss via achieving a negative energy balance.
Behavioral: Fiber Intervention
Group education and phone-based motivational interviewing to gradually increase dietary fiber consumption to 30-35 grams per day.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Body weight
Time Frame: Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Measure of body weight/mass
Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Body composition (fat mass, lean mass)
Time Frame: Measured at baseline (time 1, month 0) and post-observation (time 3, month 27)
Dual x-ray absorptiometry (DEXA) scans
Measured at baseline (time 1, month 0) and post-observation (time 3, month 27)
Fecal short chain fatty acids
Time Frame: Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Taken from fecal samples collected at home
Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Fecal bacteria measured using 16S ribosomal ribonucleic acid (rRNA) sequencing
Time Frame: Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Will include measures of diversity, abundance, etc.
Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Total Cholesterol
Time Frame: Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Measured via blood samples (unit= milligram/deciliter (mg/dL))
Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Fasting blood glucose
Time Frame: Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 33, month 27)
Measured via blood samples (unit=mg/dL)
Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 33, month 27)
Healthy Eating Index Scores measured using Health Eating Index 2020 (HEI-2020)
Time Frame: Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Taken from 3 day diet records (score range=0-100, higher=better diet quality)
Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Three-Factor Eating Questionnaire
Time Frame: Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Resulting scores in uncontrolled eating (range=9-36), cognitive restraint (range=3-12), and emotional eating (range=6-24); higher scores indicate more of that particular eating behavior
Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Implicit Association Test
Time Frame: Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Represented with a total D variable (No range, but more negative = greater preference for unprocessed food)
Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Behavioral Inhibition System/Behavioral Approach System (BIS/BAS) Scale
Time Frame: Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Score ranges from 20 to 80, with higher scores indicating greater behavioral inhibition and behavioral activation
Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Executive Function: Tower Test (Delis-Kaplan Executive Function System)
Time Frame: Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Total Achievement Score (range=0-30, higher = higher executive function)
Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Executive Function: Color-Word Interference Test (Delis-Kaplan Executive Function System)
Time Frame: Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Scaled inhibition/switching scores (score range=1-19, higher = higher executive function)
Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Skin Carotenoid scores measured via the Veggie Meter
Time Frame: Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Veggie Meter; score range 0-800 (higher=greater skin carotenoids (i.e., consumption of more fruits/vegetables)
Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
High-density lipoprotein (HDL) cholesterol
Time Frame: Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Measured via blood samples (unit=mg/dL)
Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Low-density lipoprotein (LDL) cholesterol
Time Frame: Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)
Measured via blood samples (unit=mg/dL)
Measured at baseline (time 1, month 0), post-intervention (time 2, month 15), and post-observation (time 3, month 27)

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Oklahoma State University

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 10, 2023

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
January 31, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
February 28, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
July 28, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 24, 2024

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
January 29, 2024

Study Record Updates

Last Update Posted (Estimated)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 29, 2025

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 23, 2025

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2025

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • IRB-23-59-STW

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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