Ketogenic Diet in Healthy Adults With Differing BMI

April 14, 2026 updated by: Kristina Petersen PhD, APD, FAHA, Penn State University

The Ketogenic Diet, Blood Lipids, and Heart Health in Healthy Adults With Differing BMI

The goal of this clinical trial is to examine the effect of the ketogenic diet over four weeks on blood lipid levels and risk factors for heart disease in adults with a healthy BMI compared to adults with a body mass index (BMI) in the range for obesity. The main questions it aims to answer are:

  • Does the ketogenic diet cause larger increases in "bad cholesterol" (low density lipoprotein-cholesterol) in adults with a healthy BMI compared to adults with BMI in the range for obesity?
  • Does the ketogenic diet cause larger decreases in vascular health in adults with a healthy BMI compared to adults with BMI in the range for obesity?

Participants will:

  • Consume all of the study food provided and avoid intake of non-study foods during the 28-day diet period
  • Visit the metabolic kitchen daily (Monday-Friday) to pick up meals
  • Attend 5 fasting visits at the Clinical Research Center for testing

Study Overview

Status

Status

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

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.

Detailed Description

This is a controlled feeding study investigating if four weeks on the ketogenic diet will cause differential alterations in blood lipids and lipoproteins, vascular health as measured by fasting flow mediated dilation (FMD), and mechanistic markers of lipid metabolism in adults with normal weight when compared to adults with obesity. Outcomes will be measured at both the beginning and end of the study on two consecutive days, for a total of four clinic appointments.

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.
25

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

  • Name: Kristina S Petersen, PhD
  • Phone Number: 814-865-7206
  • Email: kup63@psu.edu

Study Locations

  • United States
    • Pennsylvania
      • University Park, Pennsylvania, United States, 16802
        • Penn 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

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  1. Age 25-45 years
  2. Fasting direct LDL-C ≤100 mg/dL
  3. BMI of 18.5-22 kg/m2 or 30-35 kg/m2
  4. Blood pressure <140/90 mmHg
  5. Fasting blood glucose <126 mg/dL
  6. Fasting triglycerides <350 mg/dL
  7. ≤10% change in body weight for 6 months prior to enrollment

Exclusion Criteria:

  1. Have type 1 or type 2 diabetes or fasting blood glucose ≥126 mg/dL
  2. Prescription of anti-hypertensive, lipid-lowering or glucose-lowering drugs
  3. Intake of supplements that affect the outcomes of interest and unwilling to cease during the study period
  4. Diagnosed liver, kidney, or autoimmune disease
  5. Prior cardiovascular event (e.g., stroke, heart attack)
  6. Current pregnancy or intention of pregnancy within the next 2 months
  7. Lactation within prior 6 months
  8. Follows a vegetarian or vegan diet
  9. Food allergies/intolerance/sensitives/dislikes of foods included in the study menu
  10. Antibiotic use within the prior 1 month
  11. Oral steroid use within the prior 1 month
  12. Use of tobacco or nicotine containing products within the past 6 months
  13. Cancer at any site within the past 10 years (eligible if ≥10 years without recurrence) or non-melanoma skin cancer with in the past 5 years (eligible if ≥5 years without recurrence)
  14. Participation in another clinical trial within 30 days of baseline
  15. Currently following a restricted or weight loss diet
  16. Previously consumed the ketogenic diet for more than 1 week
  17. Prior bariatric surgery
  18. Intake of >14 alcoholic drinks/week and/or lack of willingness to consume no alcohol while enrolled in the study and/or not willing to avoid alcohol consumption for 48 hours prior to test visits
  19. Current or past eating disorder
  20. Principal Investigator discretion related to the potential participant's ability to adhere to the study requirements including being able to come to the metabolic kitchen to pick-up food five days per week
  21. Planning to relocate out of the State College area in the next 2 months
  22. Unwilling to refrain from plasma/blood donations during the study
  23. Previously diagnosed familial hypercholesterolemia
  24. If a potential participant takes thyroid medicine, abnormal thyroid stimulating hormone (TSH) concentration (TSH outside of normal range of 0.5 - 4.5 mIU/L)

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: Non-Randomized
  • Interventional Model: Parallel 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: Low BMI
BMI 18.5 - 22 kg/m^2 Intervention: Ketogenic diet 28 days
Other: Ketogenic Diet
A ketogenic diet with 5% carbohydrate, 18% protein, and 77% fat by percent kcal.
Active Comparator: High BMI
BMI 30-35 kg/m^2 Intervention: Ketogenic diet 28 days
Other: Ketogenic Diet
A ketogenic diet with 5% carbohydrate, 18% protein, and 77% fat by percent kcal.

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
LDL-cholesterol concentration change from baseline
Time Frame: 4 weeks
Assessed from fasting blood draw expressed in mg/dL. LDL-cholesterol will be measured directly via enzymatic assay. Change in LDL-cholesterol will be calculated as the mean of the end of diet measures (i.e., mean of day 29 and day 30 values) minus the mean of the baseline measures (i.e., mean of day 1 and day 2 values).
4 weeks

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
Endothelial function - Flow Mediated Dilation (FMD) change from baseline
Time Frame: 4 weeks
Assessed by fasting brachial arterial ultrasound after transient ischemia expressed in percentage (%). Change in FMD will be calculated as the end of diet measure minus the baseline measure.
4 weeks
Triglycerides concentration change from baseline
Time Frame: 4 weeks
Assessed from fasting blood draw expressed in mg/dL. Change in triglycerides will be calculated as the mean of the end of diet measures (i.e., mean of day 29 and day 30 values) minus the mean of the baseline measures (i.e., mean of day 1 and day 2 values).
4 weeks
Total cholesterol concentration change from baseline
Time Frame: 4 weeks
Assessed from fasting blood draw expressed in mg/dL. Change in total cholesterol will be calculated as the mean of the end of diet measures (i.e., mean of day 29 and day 30 values) minus the mean of the baseline measures (i.e., mean of day 1 and day 2 values).
4 weeks
HDL-cholesterol concentration change from baseline
Time Frame: 4 weeks
Assessed from fasting blood draw expressed in mg/dL. Change in HDL-cholesterol will be calculated as the mean of the end of diet measures (i.e., mean of day 29 and day 30 values) minus the mean of the baseline measures (i.e., mean of day 1 and day 2 values).
4 weeks
Concentration of LDL and triglyceride-rich lipoprotein subparticles change from baseline
Time Frame: 4 weeks
Measured via Nuclear Magnetic Resonance and expressed in nmol/L. Change in concentration will be calculated as the end of diet measure minus the baseline measure.
4 weeks
Concentration of HDL subparticles change from baseline
Time Frame: 4 weeks
Measured via Nuclear Magnetic Resonance and expressed in µmol/L. Change in concentration will be calculated as the end of diet measure minus the baseline measure.
4 weeks
Size of LDL, HDL, and triglyceride-rich lipoprotein particles change from baseline
Time Frame: 4 weeks
Measured via Nuclear Magnetic Resonance and expressed in nm. Change in size will be calculated as the end of diet measure minus the baseline measure.
4 weeks
Central systolic and diastolic blood pressure change from baseline
Time Frame: 4 weeks
Assessed using a SphymoCor Xcel (Atcor Medical) and expressed in mmHg. Change in blood pressures will be calculated as the end of diet measure minus the baseline measure.
4 weeks
Brachial systolic and diastolic blood pressure change from baseline
Time Frame: 4 weeks
Assessed using a SphymoCor Xcel (Atcor Medical) and expressed in mmHg. Change in blood pressures will be calculated as the end of diet measure minus the baseline measure.
4 weeks
Carotid-femoral pulse wave velocity change from baseline
Time Frame: 4 weeks
A measure of arterial stiffness - assessed using a SphymoCor Xcel (Atcor Medical) and expressed in meters/second. Change in pulse wave velocity will be calculated as the end of diet measure minus the baseline measure.
4 weeks
Serum Insulin concentration change from baseline
Time Frame: 4 weeks
Assessed in a fasting blood draw and expressed in micro IU/mL. Change in insulin will be calculated as the mean of the end of diet measures (i.e., mean of day 29 and day 30 values) minus the mean of the baseline measures (i.e., mean of day 1 and day 2 values).
4 weeks
Plasma glucose concentration change from baseline
Time Frame: 4 weeks
Assessed in a fasting blood draw and expressed in mg/dL. Change in glucose will be calculated as the mean of the end of diet measures (i.e., mean of day 29 and day 30 values) minus the mean of the baseline measures (i.e., mean of day 1 and day 2 values).
4 weeks
Homeostatic model assessment for insulin resistance (HOMA-IR) change from baseline
Time Frame: 4 weeks
Calculated from insulin and glucose measured from a fasting blood sample. Calculated as (insulin × glucose) / 22.5. Change in HOMA-IR will be calculated as the mean of the end of diet measures (i.e., mean of day 29 and day 30 values) minus the mean of the baseline measures (i.e., mean of day 1 and day 2 values).
4 weeks
Cholesteryl ester transfer protein (CETP) activity change from baseline
Time Frame: 4 weeks
Assessed in fasting plasma samples using an enzymatic activity kit. Change in CETP activity will be calculated as the end of diet measure minus the baseline measure.
4 weeks
Lipoprotein lipase (LPL) activity change from baseline
Time Frame: 4 weeks
Assessed in fasting plasma samples using an enzymatic activity kit. Change in LPL activity will be calculated as the end of diet measure minus the baseline measure.
4 weeks
Angiopoietin-Like Protein 3 (ANGPTL3) concentration change from baseline
Time Frame: 4 weeks
Assessed in fasting plasma samples using an ELISA kit and expressed in ng/mL. Change in ANGPTL3 concentration will be calculated as the end of diet measure minus the baseline measure.
4 weeks
Angiopoietin-Like Protein 4 (ANGPTL4) concentration change from baseline
Time Frame: 4 weeks
Assessed in fasting plasma samples using an ELISA kit and expressed in ng/mL. Change in ANGPTL4 concentration will be calculated as the end of diet measure minus the baseline measure.
4 weeks
Angiopoietin-Like Protein 8 (ANGPTL8) concentration change from baseline
Time Frame: 4 weeks
Assessed in fasting plasma samples using an ELISA kit and expressed in pg/mL. Change in ANGPTL8 concentration will be calculated as the end of diet measure minus the baseline measure.
4 weeks
Glucagon concentration change from baseline
Time Frame: 4 weeks
Assessed from fasting blood draw expressed in pg/mL. Change in glucagon concentration will be calculated as the mean of the end of diet measures (i.e., mean of day 29 and day 30 values) minus the mean of the baseline measures (i.e., mean of day 1 and day 2 values).
4 weeks
Total adiposity change from baseline
Time Frame: 4 weeks
Assessed from Dual-energy X-ray absorptiometry as % body mass. Change in total adiposity will be calculated as the end of diet measure minus the baseline measure.
4 weeks
Estimated visceral adipose tissue change from baseline
Time Frame: 4 weeks
Assessed from Dual-energy X-ray absorptiometry and calculated by software in grams (g). Change in estimated visceral adipose tissue will be calculated as the end of diet measure minus the baseline measure.
4 weeks
Alanine transaminase (ALT) change from baseline
Time Frame: 4 weeks
Assessed from fasting blood draw expressed in U/L. Change in ALT concentration will be calculated as the mean of the end of diet measures (i.e., mean of day 29 and day 30 values) minus the mean of the baseline measures (i.e., mean of day 1 and day 2 values).
4 weeks
Aspartate transaminase (AST) change from baseline
Time Frame: 4 weeks
Assessed from fasting blood draw expressed in U/L. Change in AST concentration will be calculated as the mean of the end of diet measures (i.e., mean of day 29 and day 30 values) minus the mean of the baseline measures (i.e., mean of day 1 and day 2 values).
4 weeks

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Composition of the gut microbiota
Time Frame: Baseline, 4 weeks
Measured using 16 s rRNA gene sequencing
Baseline, 4 weeks

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.
Penn 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.
January 29, 2025

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.
March 31, 2026

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.
March 31, 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 15, 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.
July 19, 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.
July 23, 2024

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.
April 15, 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.
April 14, 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.
April 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.
  • KTO

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified individual participant data will be deposited into an open access repository once results from all pre-specified primary and secondary outcomes are published.

IPD Sharing Time Frame

After publication of all pre-specified primary and secondary outcomes

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ANALYTIC_CODE

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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