Fructose: Substrate, Stimulus, or Both?

July 8, 2026 updated by: Touro University, California
This objective of this study is to use sensitive methodology under controlled conditions to investigate the mechanisms by which fructose consumption contributes to excess fatty acid synthesis and elevations in blood glucose levels following consumption of meals containing fructose.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

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.
35

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 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

20 years to 55 years (Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Body Mass Index 22 to 35 kg/m2
  • Prediabetic (HbA1c 5.7% to 6.5%) or hyperinsulinemic (fasting insulin ≥12 µIU/mL) but non-diabetic (fasting glucose <126mg/dL and HbA1c < 6.5%) ; or normal control (fasting insulin <10 µIU/mL, fasting glucose <100 mg/dL, and HbA1c < 5.7%)

Exclusion Criteria:

  • Pregnancy or lactation within the past six months
  • Type 1 or 2 diabetes mellitus
  • History of liver disease or aspartate aminotransferase (AST) and alanine aminotransferase (ALT) 2x the upper limit of normal (ULN);
  • Fasting triglyceride or total cholesterol levels above 95th percentile for age and sex;
  • Hemoglobin or hematocrit below the lower limit of normal for sex;
  • Report of hepatitis or HIV infection;
  • History of cancer, use of any anti-diabetic medications or hypolipidemic agents in the past six months;
  • History of surgical procedure for obesity;
  • Self-reported change in body weight >5% in the past six months;
  • History of other conditions known to affect insulin sensitivity and lipid metabolism;
  • Known intolerance to acetaminophen or components of the liquid test meals.

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: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Triple

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: High fructose meal, with fructose label
2-13C fructose incorporated into a meal with high fructose content
Other: High fructose, fructose labeled meal
Liquid meal containing high fructose (16% of energy), labeled with 2-13C fructose
Experimental: High fructose meal, with pyruvate label
2-13C pyruvate incorporated into a meal with high fructose content
Other: High fructose, pyruvate labeled meal
Liquid meal containing high fructose (16% of energy), labeled with 2-13C pyruvate
Experimental: Low fructose meal, with fructose label
2-13C fructose incorporated into a meal with low fructose content
Other: Low fructose, fructose labeled meal
Liquid meals containing low fructose (6% of energy), labeled with 2-13C fructose
Experimental: Low fructose meal, with pyruvate label
2-13C pyruvate incorporated into a meal with low fructose content
Other: Low fructose, pyruvate labeled meal
Liquid meal containing low fructose (6% of energy), labeled with 2-13C pyruvate

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
Hepatic fractional de novo lipogenesis in triglyceride rich lipoprotein (TRL)
Time Frame: 6 hours
Measured by the detection of 13C carbons in TRL-palmitate from administered 13C labeled pyruvate or 13C labeled fructose.
6 hours
Rate of appearance of UDP-glucose
Time Frame: 6 hours
An estimate of hepatic glycogen flux measured by administration of D1 galactose and acetaminophen
6 hours
Rate of appearance of blood glucose from gluconeogenesis
Time Frame: 6 hours
Measured by the dilution method of labeled glucose
6 hours

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
Serum triglyceride concentration
Time Frame: 6 hours
Fasting and postprandial serum triglyceride levels
6 hours
Serum glucose concentration
Time Frame: 6 hours
Fasting and postprandial serum triglyceride levels
6 hours
Serum lactate concentration
Time Frame: 6 hours
Fasting and postprandial serum lactate levels
6 hours
Serum insulin concentration
Time Frame: 6 hours
Fasting and postprandial insulin levels
6 hours
Serum free fatty acid concentration
Time Frame: 6 hours
Fasting and postprandial fatty acid levels
6 hours
Enteral (chylomicron) fractional de novo lipogenesis (DNL)
Time Frame: 6 hours
Measured by the detection of 13C carbons in chylomicron-palmitate from administered 13C labeled pyruvate or 13C labeled fructose.
6 hours
Hepatic (VLDL) fractional de novo lipogenesis (DNL)
Time Frame: 6 hours
Measured by the detection of 13C carbons in VLDL-palmitate from administered 13C labeled pyruvate or 13C labeled fructose.
6 hours
Extrasplanchnic fructose
Time Frame: 6 hours
Calculated using total plasma fructose, plasma 2-13C fructose enrichment, and endogenous fructose production
6 hours
Whole body fructose oxidation
Time Frame: 6 hours
Measured by 13C atom % excess in exhaled breath, and VCO2 by indirect calorimetry
6 hours

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: Jean-Marc Schwarz, 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.
September 15, 2019

Primary Completion (Estimated)

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, 2026

Study Completion (Estimated)

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.
July 20, 2027

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).
November 14, 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.
November 15, 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.
November 19, 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.
July 10, 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.
July 8, 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.
July 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.
  • M-3018

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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