Dietary Fiber and Time Restricted Eating (FIBER+TRE)

July 1, 2026 updated by: University of Oklahoma

Examining the Independent and Combined Effects of Dietary Fiber and Time Restricted Eating on Indicators of Cancer Risk: the Fiber and Time Restricted Eating (F.I.T.) Study

This study is seeking to examine combinations of two different dietary interventions on cancer risk.

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 (Estimated)

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.
90

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
    • Ohio
      • Columbus, Ohio, United States, 43230
        • University of Oklahoma Health Sciences

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 age
  • Body mass index ≥30 kg/m2
  • Dietary fiber intake ≤15 g/day
  • Compatible cell phone for use of ecological momentary assessment app

Exclusion Criteria:

  • Self-reported diagnosis that precludes fiber intake (e.g., inflammatory bowel disease)
  • Food allergies or intolerances that limit ability to engage with the intervention
  • Positive screen on the SCOFF eating disorder screener39
  • Current self-reported use of GLP-1 receptor agonists
  • Currently pregnant or breastfeeding, or planning to become pregnant

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: Prevention
  • 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: Time Restricted Eating (TRE)
Behavioral: Time Restricted Eating
10-hour Time Restricted Eating (TRE)
Experimental: Fiber for Improvement of Behavior, Eating, and Risk (FIBER)
Behavioral: Group education
Group education about dietary fiber
Behavioral: Counseling
Counseling and motivational interviewing to promote uptake of diet changes
Experimental: FIBER and TRE
Behavioral: Group education
Group education about dietary fiber
Behavioral: Counseling
Counseling and motivational interviewing to promote uptake of diet changes
Behavioral: Time Restricted Eating
10-hour Time Restricted Eating (TRE)

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
Dietary fiber intake
Time Frame: Baseline, post-intervention (approximately 3 months), and post-observation (approximately 12 months)
Dietary fiber intake as reported on 3-day diet records and analyzed according to Nutrition Data System for Research; reported as a mean intake over three days in grams per day
Baseline, post-intervention (approximately 3 months), and post-observation (approximately 12 months)

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 mass/weight
Time Frame: Baseline, post-intervention (approximately 3 months), and post-observation (approximately 12 months)
Body mass/weight will be measured in kilograms
Baseline, post-intervention (approximately 3 months), and post-observation (approximately 12 months)
Blood-based measures of inflammation
Time Frame: Baseline, post-intervention (approximately 3 months), and post-observation (approximately 12 months)
Venous blood samples will be collected and analyzed for inflammatory markers: Granulocyte-macrophage colony-stimulating factor (GM-CSF), interferon-gamma (IFN-γ), interleukin-1 beta (IL-1β), interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-6 (IL-6), interleukin-8 (IL-8), interleukin-10 (IL-10), and tumor necrosis factor-alpha (TNF-α).
Baseline, post-intervention (approximately 3 months), and post-observation (approximately 12 months)
Blood-based measures of oxidative stress
Time Frame: Baseline, post-intervention (approximately 3 months), and post-observation (approximately 12 months)
Venous blood samples will be collected and analyzed for measures of oxidative stress, including reactive oxygen species and lipid peroxidation
Baseline, post-intervention (approximately 3 months), and post-observation (approximately 12 months)
Blood-based measures of insulin resistance
Time Frame: Baseline, post-intervention (approximately 3 months), and post-observation (approximately 12 months)
Insulin resistance will be measured via assessment of insulin and glucose in venous blood samples, and used to assess Homeostatic Model Assessment of Insulin Resistance (HOMA-IR)
Baseline, post-intervention (approximately 3 months), and post-observation (approximately 12 months)
Affect
Time Frame: Daily for three months
Self-reported affect will be assessed using ecological momentary assessment, delivered via cell phone
Daily for three months
Sleep
Time Frame: Daily for three months
Sleep will be measured via Fitbits, assessed as mean minutes/night
Daily for three months
Physical Activity
Time Frame: Daily for three months
Physical activity will be measured via Fitbits, assessed as mean steps/day
Daily for three months
Blood pressure
Time Frame: Baseline, post-intervention (approximately 3 months), and post-observation (approximately 12 months)
Blood pressure (systolic and diastolic) will be measured at each time frame (in millimeters of mercury [mmHg])
Baseline, post-intervention (approximately 3 months), and post-observation (approximately 12 months)

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.
University of Oklahoma

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.
December 10, 2025

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.
June 30, 2027

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.
June 30, 2027

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).
October 20, 2025

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.
October 20, 2025

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.
October 22, 2025

Study Record Updates

Last Update Posted (Actual)

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.
July 6, 2026

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.
July 1, 2026

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.
July 1, 2026

More Information

Terms related to this study

Keywords

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.
  • 18665

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

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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