Dietary Fiber and Time Restricted Eating (FIBER+TRE)

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: Active, not recruiting
• Conditions: Cancer Prevention; Diet Habits
• Intervention / Treatment: Behavioral: Group education; Behavioral: Counseling; Behavioral: Time Restricted Eating

• Study Type: Interventional
• Enrollment (Estimated): 90
• Phase: Not Applicable

Contacts and Locations

Study Locations

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

Participation Criteria

Eligibility Criteria

• 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

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Factorial Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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

Outcome Measure	Measure Description	Time Frame
Dietary fiber intake	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

Outcome Measure	Measure Description	Time Frame
Body mass/weight	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	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	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	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	Self-reported affect will be assessed using ecological momentary assessment, delivered via cell phone	Daily for three months
Sleep	Sleep will be measured via Fitbits, assessed as mean minutes/night	Daily for three months
Physical Activity	Physical activity will be measured via Fitbits, assessed as mean steps/day	Daily for three months
Blood pressure	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

• Sponsor: University of Oklahoma

Study record dates

Study Major Dates

• Study Start (Actual): December 10, 2025
• Primary Completion (Estimated): June 30, 2027
• Study Completion (Estimated): June 30, 2027

Study Registration Dates

• First Submitted: October 20, 2025
• First Submitted That Met QC Criteria: October 20, 2025
• First Posted (Actual): October 22, 2025

Study Record Updates

• Last Update Posted (Actual): July 6, 2026
• Last Update Submitted That Met QC Criteria: July 1, 2026
• Last Verified: July 1, 2026

More Information

Terms related to this study

• Keywords: Weight loss; Time restricted feeding; Diet; Fasting; Time restricted eating
• Additional Relevant MeSH Terms: Body Weight; Body Weight Changes; Pathological Conditions, Signs and Symptoms; Behavior; Signs and Symptoms; Behavior, Animal; Weight Loss; Feeding Behavior; Fasting; Intermittent Fasting; Health Services; Health Care Facilities Workforce and Services; Community Health Services; Behavioral Disciplines and Activities; Mental Health Services; Counseling
• Other Study ID 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