Effect of Circadian Timing of a Standardized Meal on Postprandial Glucose Response in Healthy Adults

April 16, 2026 updated by: King Faisal University
This randomized crossover study aims to investigate the effect of circadian timing of a standardized meal (morning versus evening consumption) on postprandial glucose response in healthy adults. Postprandial glucose will be assessed using the incremental area under the curve (iAUC) over 120 minutes.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet 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 (Estimated)

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.
32

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

  • Saudi Arabia
    • Eastern Province
      • Al-Ahsa, Eastern Province, Saudi Arabia, 31982
        • King Faisal University
        • Contact:

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
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Healthy adults aged 18 years and older
  • Able and willing to provide informed consent
  • Able to comply with study procedures

Exclusion Criteria:

  • Diagnosis of diabetes or any metabolic disorder affecting glucose regulation
  • Use of any medications
  • Pregnant or breastfeeding women
  • Night shift workers or individuals with irregular sleep patterns

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: 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: Morning Meal Condition
Participants will consume a standardized test meal in the morning following an overnight fasting period of at least 8 hours. Postprandial glucose will be measured over 120 minutes.
Other: Standardized Test Meal
The standardized test meal provided 50 g of carbohydrates of weighed portions of white bread and jam, served with 200 mL of water.
Experimental: Evening Meal Condition
Participants will consume the same standardized test meal in the evening following a standardized fasting period of at least 8 hours prior to the test meal. Postprandial glucose will be measured over 120 minutes.
Other: Standardized Test Meal
The standardized test meal provided 50 g of carbohydrates of weighed portions of white bread and jam, served with 200 mL of water.

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
Incremental Area Under the Curve (iAUC) for Postprandial Glucose
Time Frame: Baseline to 120 minutes after consumption of the standardized test meal
The primary objective of this study is to investigate the effect of circadian timing of a standardized test meal (morning versus evening consumption) on postprandial glucose response in healthy adults, assessed as the incremental area under the curve (iAUC) for capillary blood glucose over 120 minutes following meal consumption
Baseline to 120 minutes after consumption of the standardized test meal

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
Peak Postprandial Glucose (Morning vs Evening)
Time Frame: Baseline to 120 minutes after consumption of the standardized test meal
Peak capillary blood glucose concentration measured within 120 minutes after consumption of the standardized test meal, under morning and evening conditions
Baseline to 120 minutes after consumption of the standardized test meal
Time to Peak Glucose (Morning vs Evening)
Time Frame: Baseline to 120 minutes after consumption of the standardized test meal
Time required to reach peak capillary blood glucose concentration following meal consumption, under morning and evening conditions.
Baseline to 120 minutes after consumption of the standardized test meal
Postprandial Glucose Profile (Morning vs Evening)
Time Frame: Baseline, 15, 30, 60, 90, and 120 minutes after consumption of the standardized test meal
Capillary blood glucose concentrations measured at predefined time points following consumption of the standardized test meal, under morning and evening conditions.
Baseline, 15, 30, 60, 90, and 120 minutes after consumption of the standardized test meal

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
Night Eating Behavior
Time Frame: Baseline
Night eating behavior will be assessed using the validated Night Eating Questionnaire to characterize nocturnal eating patterns and support interpretation of variability in postprandial glucose responses.
Baseline
Sleep Duration and Quality
Time Frame: Baseline
Sleep duration and quality will be assessed using a validated sleep questionnaire administered prior to each study visit to support interpretation of postprandial glucose responses.
Baseline
Chronotype
Time Frame: Baseline
Chronotype will be assessed at baseline using the validated Questionnaire to characterize individual circadian preference and support interpretation of postprandial glucose responses.
Baseline

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.
King Faisal University

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.
Saudi Food and Drug Authority

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 (Estimated)

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.
April 15, 2026

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.
May 30, 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.
May 30, 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).
April 16, 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.
April 16, 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 22, 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 22, 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 16, 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

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.
  • ETHICS3992

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

De-identified individual participant data (IPD) collected in this study will not be made publicly available. Data will be used for research purposes by the study investigators only

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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