Investigating the Production of Lipoproteins and Acetyl-CoA During a Ketogenic Diet (PLAK)

May 14, 2026 updated by: Touro University, California
The purpose of this study is to understand how the reduction in dietary carbohydrates in a very-low carbohydrate ketogenic diet impacts the synthesis of cholesterol, fatty acid, and ketones, and the turnover rate of VLDL and chylomicron particles.

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

Participants will consume a standard American diet for one week followed by a very-low carbohydrate ketogenic diet (VLCKD, <50 grams carbohydrate/day) for two weeks. Participants will undergo an oral stable isotope tracer study during each diet to measure de novo synthesis of fatty acid, cholesterol, ketone bodies, and for measurement of apolipoprotein B and triglyceride kinetics.

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.
4

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 Locations

  • United States
    • California
      • Vallejo, California, United States, 94592
        • Touro University California

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

18 years to 50 years (Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Male
  • 18-50 years old

Exclusion Criteria:

  • Use of nicotine products
  • Has dietary restrictions
  • Lactose intolerance
  • History of GI disorders, diabetes, liver, kidney, or thyroid disorders
  • Taking hypolipidemic, anti-diabetic, anti-hypertensive, or anti-depression medication
  • Screening plasma triglyceride < 50mg/dl or >500mg/dl
  • Screening glucose > 125mg/dl
  • Screening total and LDL-Cholesterol over 95th %tile for age and sex
  • BP > 160/95 mmHg
  • Weight loss/gain > 5% in the previous 3 months (self-reported)

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: Non-Randomized
  • Interventional Model: Crossover 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.
Active Comparator: Baseline diet
1 week baseline diet
Other: Standard American diet
Standard American diet with 50% energy from carbohydrate, 30% from fat, and 20% from protein.
Experimental: Very low carbohydrate diet
2 week very low carbohydrate ketogenic diet
Other: Very low carbohydrate diet
Ketogenic diet with <50g carbohydrate, 60-75% energy from fat, and 20% from protein

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
Change in total cholesterol
Time Frame: Day 3-7 to Day 17-21
Change in serum total cholesterol between Day 3-7 (average value) to Day 17-21 (average value)
Day 3-7 to Day 17-21
Change in low density lipoprotein (LDL) cholesterol
Time Frame: Day 3-7 to Day 17-21
Change in serum LDL cholesterol between Day 3-7 (average value) to Day 17-21 (average value)
Day 3-7 to Day 17-21
Change in high density lipoprotein (HDL) cholesterol
Time Frame: Day 3-7 to Day 17-21
Change in serum HDL cholesterol between Day 3-7 (average value) to Day 17-21 (average value)
Day 3-7 to Day 17-21
Change in apolipoprotein B (apoB) kinetics
Time Frame: Day 3-7 to Day 17-21
Change in apoB turnover rates in LDL and very low density lipoprotein plasma fractions as measured using 2H2 leucine incorporation into apoB and mathematical modeling
Day 3-7 to Day 17-21

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
Change in fractional hepatic de novo lipogenesis
Time Frame: Day 3 to Day 17
Measured by the detection of incorporated 1-13C sodium acetate into palmitate in triglyceride rich lipoproteins (TRL)
Day 3 to Day 17
Change in fractional cholesterol synthesis
Time Frame: Day 3 to Day 17
Measured by the detection of incorporated 1-13C sodium acetate into cholesterol in plasma
Day 3 to Day 17
Change in ketone body synthesis
Time Frame: Day 3 to Day 17
Measured by the detection of incorporated 1-13C sodium acetate into ketone bodies in plasma
Day 3 to Day 17
Change in TRL-triglyceride kinetics
Time Frame: Day 3 to Day 17
Change in TRL- triglyceride assembly rates as measured using 2-13C glycerol and mathematical modeling
Day 3 to Day 17
Change in triglyceride lipolysis
Time Frame: Day 3 to Day 17
Measured by the dilution of administered 2-13C glycerol in plasma
Day 3 to Day 17
Change in serum glucose concentration
Time Frame: Day 3 to Day 17
Change in fasting and postprandial serum glucose levels
Day 3 to Day 17
Change in serum free fatty acid concentration
Time Frame: Day 3 to Day 17
Change in fasting and postprandial serum free fatty acid levels
Day 3 to Day 17
Change in serum insulin concentration
Time Frame: Day 3 to Day 17
Change in fasting and postprandial serum insulin levels
Day 3 to Day 17
Change in serum ketone body concentration
Time Frame: Day 3 to Day 17
Change in fasting and postprandial ketone body levels
Day 3 to Day 17

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.
Touro University, California

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: Grace M Jones, PhD, Touro University, California

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.
March 29, 2019

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.
April 18, 2019

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.
April 18, 2019

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).
March 29, 2019

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.
April 1, 2019

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.
April 3, 2019

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.
May 18, 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.
May 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.
November 1, 2022

More Information

Terms related to this study

Keywords

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.
  • M-0419

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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