AdiposityMetFlexHFDNCT06537401
Metabolic Adaptations to High-fat Diet
A study testing Hypercaloric, High Fat Diet in people with Adiposity and Insulin Sensitivity, run by George Washington University at 1 site in United States.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 20 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Adiposity, Insulin Sensitivity, Impaired Glucose Tolerance
- What is being tested?
- Hypercaloric, High Fat Diet
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 2 participants
- Where
- 1 siteUnited States
- Study dates
- 12 Aug 2024to 31 Dec 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 to 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 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
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country.
United States1 site
George Washington University School of Public Health
Washington D.C., District of Columbia, 20052
About this study
Official title: 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
- Being tested
- Hypercaloric, High Fat Diet
- Keywords
- Metabolism, Feeding, Substrate Oxidation, Metabolic Flexibility, High Fat Diet, Insulin Sensitivity
- Medical subject headings
- Obesity, Insulin Resistance, Glucose Intolerance
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Hypercaloric, High Fat DietBehavioural
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.
| Study group | Role | What they receive |
|---|---|---|
| Hypercaloric, High Fat Diet | Experimental | 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. Receives: Behavioral: Hypercaloric, High Fat Diet |
What is being measured
The primary outcome is the main question the study is designed to answer.
Postprandial Metabolic Flexibility
Mean difference respiratory exchange ratio during an oral glucose tolerance test following a high fat diet
Measured: 3 Days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted5 Aug 2024
- Study start12 Aug 2024
- Primary completion31 Dec 2024
- Study completion31 Dec 2024
Why it stopped: Feasibility of subjects completing the 3 day high fat diet protocol and multiple oral glucose tests
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for AdiposityStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- Non-Randomized Crossover
- Masking
- None (open label)
- Enrolment
- 2 participants (actual)
Sponsor and investigators
- Lead sponsor
- George Washington University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Matthew Barberio, George Washington University
- Investigators
- Matthew D Barberio, PhD, Principal investigator, George Washington University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06537401
- Sponsor's protocol ID
- NCR245732
- Acronym
- MetFlexHFD
- Status last verified
- Aug 2025
- First submitted
- 1 Aug 2024
- Last updated
- 26 Aug 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 26 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Adaptations in Postprandial Metabolic Flexibility Following a Three-day, High-fat Diet
- ClinicalTrials.gov ID
- NCT06537401
- Acronym / sponsor ID
- MetFlexHFD / NCR245732
- Keywords
- Metabolism, Feeding, Substrate Oxidation, Metabolic Flexibility, High Fat Diet, Insulin Sensitivity
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: Feasibility of subjects completing the 3 day high fat diet protocol and multiple oral glucose tests
- Enrolment
- 2 participants (actual)
- Lead sponsor
- George Washington UniversityUniversity, hospital or other
- Study start
- 12 Aug 2024 (actual)
- Primary completion
- 31 Dec 2024 (actual)
- Study completion
- 31 Dec 2024 (actual)
- First posted
- 5 Aug 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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 design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Non-Randomized Crossover
| Arm | Type | Receives |
|---|---|---|
| Hypercaloric, High Fat Diet | Experimental | Behavioral: Hypercaloric, High Fat DietFor 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. |
Who may qualify
- Ages
- 20 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- 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
Key exclusion criteria (8 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Hypercaloric, High Fat DietParticipants 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. | Behavioural | Hypercaloric, High Fat Diet |
Primary outcome
Postprandial Metabolic Flexibility
Time frame: 3 Days
Mean difference respiratory exchange ratio during an oral glucose tolerance test following a high fat diet
Results and safety
The study was stopped early (reason given: Feasibility of subjects completing the 3 day high fat diet protocol and multiple oral glucose tests). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 26 Aug 2025.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Matthew D Barberio, PhD principal investigator
George Washington University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Hypercaloric, High Fat Diet in people with Adiposity and Insulin Sensitivity, run by George Washington University at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 8 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: stopped early, as of the sponsor's last update on 26 Aug 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study was stopped early (reason given: Feasibility of subjects completing the 3 day high fat diet protocol and multiple oral glucose tests). Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Postprandial Metabolic Flexibility (time frame: 3 Days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 26 Aug 2025; AzTrials last refreshed its copy on 31 Oct 2026.