Metabolic Adaptations to High-fat Diet (MetFlexHFD)

August 21, 2025 updated by: Matthew Barberio, George Washington University

Adaptations in Postprandial Metabolic Flexibility Following a Three-day, High-fat Diet

The purpose of this study is to understand how the body's response after a meal is influenced by insulin and sugar in the blood. The primary question this study seeks to address is what is the effect of reduced insulin sensitivity on postprandial metabolic flexibility to an oral glucose tolerance test. We will recruit 50 adults (ages 20-45; 50% female) who are otherwise healthy (no known clinical diagnosis) into our non-randomized crossover trial to determine the effect of changes in insulin sensitivity on metabolic response to feeding. Insulin sensitivity will be decreased using a three-day high-fat diet (HFD) with extra calories. Whole-body metabolism will be measured during a standard 75-gram oral glucose tolerance test (OGTT). Metabolic response to feeding (e.g. OGTT) will be compared before and after the HFD and compared with the control diet to understand the effect of decreased insulin sensitivity on the metabolic response to feeding. The role of biological sex as a moderator of the effect of increased insulin resistance on postprandial metabolic flexibility will also be investigated

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Terminated

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.
2

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 Contact Backup

Study Locations

  • United States
    • District of Columbia
      • Washington D.C., District of Columbia, United States, 20052
        • George Washington University School of Public Health

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

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Males or Females between the ages of 20 and 45 years
  • Body mass index (BMI) of 18.5-29.9 kg/m2
  • Low risk for medical complications as determined by physical activity readiness questionnaire (PARQ).
  • Low risk for food insecurity via the Hunger Vital Sign screener

Exclusion Criteria:

  • Currently taking any antioxidant supplementation, prescription non-steroidal anti- inflammatory drugs, antibiotics, steroids, probiotics, medications for management of cholesterol, diabetes, body weight/obesity, or are undergoing transgender hormone therapy.
  • Currently pregnant (verified by urine pregnancy test)
  • Any history of disordered eating (i.e., anorexia nervosa, bulimia nervosa, binge eating disorder, etc.) or high risk for disordered eating via validated questionnaire (SCOFF)
  • Any history of gastrointestinal diseases (i.e., gastroesophageal reflux disease, irritable bowel syndrome, Celiac disease, Crohn's disease, or lactose intolerance)
  • Allergies to wheat or gluten, milk, soy, tree nuts (e.g., almonds, walnuts, pecans), or peanuts.
  • Followed a ketogenic diet within the last three months
  • Instructed by a medical provided to avoid a high-fat diet due to cardiovascular disease risk.
  • Cardiorespiratory fitness (VO2max) greater than the 90th percentile for age and sex

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: Basic Science
  • Allocation: N/A
  • Interventional Model: Single Group 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: Hypercaloric, High Fat Diet
For three calendar days participants will be asked to track all foods they eat and beverages they drink (habitual diet) in a mobile application. Following the three days following the habitual diet, participants will consume 165% of their estimated daily energy needs with 65% of those calories coming from fat.
Behavioral: Hypercaloric, High Fat Diet
Participants will select meals from a list of sample breakfast, lunch, and dinner options from grocery stores. Typical intake will be estimated as 160-170% of resting metabolic rate, which will then be multiplied by 1.65 as the target calorie intake for the HFD. Target fat intake will be 65% of the HFD calorie target. To ensure participants will achieve the desired calorie and fat intake, they will also be provided with pre-made nutrient shakes and half-and-half. Participants will supplement their food intake with one to three shakes per day for each of the three days, depending on the fat and calorie content of the foods they select. They will be asked to add half-and-half equally between across the shakes.

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
Postprandial Metabolic Flexibility
Time Frame: 3 Days
Mean difference respiratory exchange ratio during an oral glucose tolerance test following a high fat diet
3 Days

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.
George Washington University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Matthew D Barberio, PhD, George Washington 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.
August 12, 2024

Primary Completion (Actual)

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.
December 31, 2024

Study Completion (Actual)

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.
December 31, 2024

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).
August 1, 2024

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.
August 1, 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.
August 5, 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.
August 26, 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.
August 21, 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.
August 1, 2025

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.
  • NCR245732

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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