Time-restricted Eating and Circadian Health in Night Shift Workers (FastingClocks)

May 8, 2026 updated by: Rodrigo Chamorro, University of Chile

Effect of a Time-restricted Eating Protocol on Glucose Homeostasis, Markers of Circadian System, Appetite Control, and Oxidative Stress Parameters in Night Shift Workers

The goal of this clinical trial is to learn about the effect of time-restricted eating (TRE) to 10 hours per day on glucose homeostasis, markers of the circadian system, homeostatic and hedonic regulation of appetite, and inflammation/oxidative stress status in night shift workers. The main questions it aims to answer are: 1) How does a time-restricted eating protocol affect glucose homeostasis in shift workers? and 2) How does a time-restricted eating protocol affect markers of the circadian system, homeostatic and hedonic regulation of appetite, and inflammation/oxidative stress status in shift workers? Participants will be asked to follow a TRE protocol on which they must restrict their eating to a self-selected time window of 10 hours a day, with mandatory fasting time between 24:00-06:00h. for 8 weeks. Researchers will compare the intervention with an additional period of 8 weeks, in which the participants will follow their usual diet without any time restriction, to see if the intervention improves glucose regulation appetite and markers of circadian system, homeostatic and hedonic regulation of appetite, and inflammation/oxidative stress.

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 randomized, crossover, controlled, within-subject study. After recruitment, participants will be randomized to one of two conditions: i) Time-restricted eating (TRE), with an eating window of 10 hours per day but without any other diet modification (e.g., types of food or amount of energy consumed). Each participant can freely choose the starting time of their eating window. If a participant need to make modifications to the start time of their eating window, he/she may do so only once during the TRE period, and the research team must be informed. After a washout period of at least 30 days, participants will undergo ii) Regular eating (REG), during which the participants must maintain their usual eating pattern (i.e., usual eating window), without making any dietary or lifestyle changes. Each condition will have a duration of 8 weeks. Randomization will be done using computer-generated random numbers.

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.
22

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

  • Chile
    • Metropolitan Region
      • Santiago, Metropolitan Region, Chile, 8380453
        • Faculty of Medicine, University of Chile

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:

Adults (range 18 - 60 yrs.) Men and women Performing as a healthcare worker Being a shift-worker for at least 6 months in the current schedule Working in rotating shiftwork, including at least one night shift Reporting no work-related performance difficulties

Exclusion Criteria:

  • Current and chronic neurological disorders
  • Pathologies related to abnormal adrenal activity
  • Liver or kidney disease
  • Uncontrolled hypertension, dyslipidemia, and thyroid disease
  • Insulin resistance and T2D
  • BMI ≥40 kg/m2
  • Use of medications known to alter body composition, such as insulin sensitizers, glucocorticoids, or anti-depressants
  • Autoimmune diseases with acute symptoms; recent surgery of any kind (in the last 3 months);
  • Acute, chronic inflammation (usCRP >10 mg/L)
  • Following any dietary restriction (special diet) in the previous three months
  • Having a short sleep (habitual sleep duration of less than 6h per day)
  • History of bariatric surgery
  • Depression (Beck Depression Inventory) or sleep disorders (Pittsburgh Sleep Questionnaire)
  • Night-eating syndrome (Night Eating Questionnaire)
  • Intense exercise level (>3 days/week of high-intensity exercise)
  • Having traveled across time zones (at any time during the last month) and planning travel during the study
  • Pregnant or intend to become pregnant, and
  • Lactating women

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

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: Time-restricted eating
Self-selected eating window of 10 hours per day without any other dietary modification (e.g., types of food or amount of energy consumed) for 8 weeks, with 14 hours fasting per day (mandatory fasting from 00:00h until 06:00h).
Behavioral: Time-restricted eating
During the intervention (TRE) each participant will freely choose the starting time of their eating window. If needed, participant can modify the selected start time of their eating window only once during the intervention period, and the research team must be informed. After a washout period of at least 30 days, participants will undergo the opposite condition (TRE or Regular eating) after the initial randomization
No Intervention: Regular eating
Participants must maintain their usual eating pattern (i.e., usual eating window) for 8 weeks, but without any dietary or lifestyle changes

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 from Baseline in the mean fasting glycemia at 8 weeks
Time Frame: From baseline to the end of treatment (at 8 weeks), in each study period (TRE and REG)
Fasting glycemia level (in mg/dL) will be measured from fasting blood samples and measured with the hexokinase method
From baseline to the end of treatment (at 8 weeks), in each study period (TRE and REG)

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 from baseline to end of treatment (8weeks) in 24-h glycemic control
Time Frame: From baseline to the end of treatment (at 8 weeks), in each study period (TRE and REG)
24-h glycemic control (expressed in mg/dL), measured with continuous glucose monitoring (CGM) using a portable capillary glucose sensor, over 10 consecutive days.
From baseline to the end of treatment (at 8 weeks), in each study period (TRE and REG)
24-hour motor activity level (counts/min)
Time Frame: From enrollment to the end of treatment (at 8 weeks), in each study period (TRE and REG)
Motor activity will be assessed by accelerometric recordings (actigraphic data) of wrist activity. Actigraphy data will assess motor activity before and after the intervention
From enrollment to the end of treatment (at 8 weeks), in each study period (TRE and REG)
Change from Baseline in the circadian clock-genes expression at 8 weeks
Time Frame: From baseline to the end of treatment (at 8 weeks), in each study period (TRE and REG)
Clock-gene expression will be evaluated by relative expression, performing RT-stem loop real-time PCR, from fasting whole-blood samples taken at baseline and after 8 weeks, in each study period. Gene expression levels of the target sequences will be normalized to the expression of GAPDH, and will be calculated by applying equation 2-∆∆ CT.
From baseline to the end of treatment (at 8 weeks), in each study period (TRE and REG)
Change from baseline in thiobarbituric acid reactive substances (TBARS) level at 8 weeks
Time Frame: From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)]
TBARS level (in µM/ml) will be measured in plasma samples
From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)]
Change from baseline in F-8 isoprostane level at 8 weeks
Time Frame: From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)
F-8 isoprostane level (in pg/mL) will be measured in plasma samples
From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)
Change from Baseline in Appetite-related feelings at 8 weeks
Time Frame: From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)
A visual analog scale will be used to assess appetite feeling levels. Each participant rates their subjective feelings of appetite, satiety, and desire to eat using a 100 mm visual analog scale, with endpoints indicating from "not at all" (0 mm) to "extremely" (100 mm).
From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)
Change from baseline in total-, reduced- and oxidized glutathione levels at 8 weeks
Time Frame: From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)
Total-, reduced-, and oxidized glutathione levels (in µM) will be measured in plasma samples
From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)
Change from baseline in C-reactive protein levels at 8 weeks
Time Frame: From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)
C-reactive protein levels (in mg/L) will be measured in serum samples
From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)
Change from baseline in pro-inflammatory cytokine levels at 8 weeks
Time Frame: From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)
Interleukin 1β, Interleukin 6, and Tumor necrosis factor (TNF-α) levels (in pg/mL) will be measured in plasma samples.
From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)

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
Change in body mass index at 8 weeks
Time Frame: From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)
Body mass index will be calculated (expressed as kg/m2) from body weight and height anthropometric measurements, measured with light clothes and expressed as Kg (weight) and cm (height), respectively.
From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)
Change from baseline in fat mass index at 8 weeks
Time Frame: From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)
Fat mass index (in kg/m²) will be assessed by dual-energy X-ray absorptiometry (DXA) using a Lunar DPXL densitometer
From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)
Change from Baseline in sleep duration at 8 weeks
Time Frame: From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)
Sleep duration will be measured through continuous actigraphic recordings during daytime and nighttime for 10 days, and expressed in minutes
From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)
Change from baseline in fat-free mass index at 8 weeks
Time Frame: From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)
Fat-free mass index (in kg/m²) will be assessed by dual-energy X-ray absorptiometry (DXA) using a Lunar DPXL densitometer
From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)
Change from baseline in fat mass at 8 weeks
Time Frame: From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)
Fat mass (in %) will be assessed by dual-energy X-ray absorptiometry (DXA) using a Lunar DPXL densitometer
From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)
Change from baseline in muscle mass at 8 weeks
Time Frame: From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)
Muscle mass (in %) will be estimated by dual-energy X-ray absorptiometry (DXA) using a Lunar DPXL densitometer
From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)
Change from baseline in Bone Mineral Density at 8 weeks
Time Frame: From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)
Bone Mineral Density (BMD, in g/cm2) will be assessed by dual-energy X-ray absorptiometry (DXA) using a Lunar DPXL densitometer
From baseline to the end of treatment (8 weeks) in each study period (TRE and REG)

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.
University of Chile

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Agencia Nacional de Investigación y Desarrollo

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.
  • Study Chair: Lucía Cifuentes, MD, Ethics Committee for Human Subjects of the Faculty of Medicine, University of Chile

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.
October 30, 2023

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.
July 11, 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.
July 11, 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 30, 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.
February 27, 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.
March 5, 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.
May 13, 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 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.
May 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.
  • TRE-Shift-2024

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Published data generated from the study will be available from the leading author, upon reasonable request

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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