Time-restricted Feeding and Health (e-TRF)

March 26, 2026 updated by: Konstantinos Anastasiou, Harokopio University

The Effect of Early Time-restricted Feeding in Metabolic Health - Differences Between Chronotypes.

The purpose of this pilot, single-arm clinical trial is to assess the effects of time-restricted feeding on overall health, including body composition, glycemic and lipidemic profile, as well as appetite-regulating hormones, including glucagon-like peptides 1(GLP-1) oxyntomodulin, glucagon. Additionally, the study aims to evaluate the impact of this dietary pattern on circadian rhythm parameters, including acrophase, mesor, and amplitude.

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.

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.
16

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

  • Greece
    • Attica
      • Athens, Attica, Greece, 17676
        • Harokopio University of Athens

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:

  • Healthy men or women aged 18-35 years
  • Habitual daily eating window >10 hours
  • Stable body weight over the past 3 months (< ±10% change)
  • Able to provide informed consent independently

Exclusion Criteria:

  • Night shift work more than once per week
  • Presence of chronic diseases (e.g., cancer, renal or hepatic disease, inflammatory bowel disease, hypertension, diabetes, cognitive or psychiatric disorders)
  • Eating disorders
  • Use of medications affecting the intervention (e.g., corticosteroids, antidiabetics)
  • Pregnancy or planning pregnancy within the next 12 months
  • Diagnosis of insomnia

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.
Other: Time-Restricted Feeding
Participants followed a four-week regimen of ad libitum food intake from 08:00 to 18:00, followed by a 14-hour fasting period until 08:00 the next day, while maintaining habitual physical activity and sleep patterns.
Other: Time-Restricted Feeding
Ad libitum food intake from 08:00 to 18:00, followed by fasting from 18:00 to 08:00 for four weeks. Outside the eating window, water and limited amounts (1-2 servings) of very low-calorie items (e.g., tea, diet soft drinks, coffee, chewing gum <4 kcal/serving) were permitted. The intervention focused exclusively on the timing of food intake and did not impose restrictions on the quantity or type of foods consumed.

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
Changes from baseline in appetite-regulating hormones , including GLP-1 in pg/mL, oxyntomodulin in pg/mL, and glucagon in pg/mL at week 4, measured by ELISA kits.
Time Frame: Baseline and Week 4
Participants arrived at the laboratory between 08:30 and 09:00. An antecubital catheter was placed, and five blood samples were collected at fasting (0 min) and at 30, 60, 90, and 120 minutes after consuming the test meal. The test meal consisted of 100 g of S-Core FLEX Compact Protein powder (40 g carbohydrate, 29 g protein, 19 g fat) dissolved in 250 mL of water, providing 475 kcal.
Baseline and Week 4

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
Changes from baseline in circadian rhythm parameters (acrophase in degrees of Celcious, mesor in time units, amplitude in degrees of Celcious) at week 4, measured through continouous measurements in skin termperature by a thermistor.
Time Frame: Baseline and Week 4
Participants wore a wireless skin temperature sensor (Thermochron iButton® DS1921-F5) on the palmar surface of the wrist of the non-dominant hand for 2 consecutive days. Circadian rhythmicity was analyzed using Cosinor analysis, which applies the least-squares method to fit the chronobiological data to cosine functions with predetermined periods of 12 and 24 hours.
Baseline and Week 4
Changes from baseline in Body Composition, namely fat free mass in kg and fat mass in kg
Time Frame: Baseline and week 4
Participant's body composition measurement pre/post time restricted feeding protocol
Baseline and week 4
Changes from Baseline in Glycemic and Lipidemic Profile, assessed by photometry.
Time Frame: Baseline and Week 4
Biochemical measurements in blood.
Baseline and Week 4

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.
Harokopio 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.
June 4, 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.
December 16, 2025

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 16, 2025

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).
January 15, 2026

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.
March 26, 2026

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 1, 2026

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 1, 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.
March 26, 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.
March 1, 2026

More Information

Terms related to this study

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.
  • Γ-1936/02-05-2025

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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