Glycemic Effects of Meals - Repeatability Trial With Continuous Glucose Monitoring (GEM-RT CGM)

April 27, 2026 updated by: Boston University

Almost half of adults in the United States have either diabetes mellitus (DM) or prediabetes (preDM), but many are undiagnosed and unaware of their condition. Current DM diagnosis and risk prediction are based on single "snapshot" measurements including: fasting blood glucose, postprandial glucose, and hemoglobin (Hb)A1c. Continuous glucose monitoring (CGM) offers a dynamic view of glucose levels throughout the day which enables characterizing individuals' dynamic glycemic profiles in response to physiological and environmental stimuli better than the conventional point-in-time glucose quantification approaches. By analyzing glycemic patterns from CGM tracings, it may be possible to identify individuals at increased risk of developing diabetes. However, an important prerequisite is to establish the reliability and consistency of glucose response patterns captured by CGM under controlled conditions.

Participants will be given six different meals to examine the glucose responses to these meals. Two of these meals (white rice and an Ensure drink) will be given twice for each participant to investigate whether individuals have the same glucose response to the same meal given on different days. Glucose will be measured using continuous glucose monitors, that have a thin wire sensor that measures glucose under the skin every five minutes for up to 10 days.

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.

Detailed Description

This is a pilot study in which each participant undergoes six meal challenges (one each morning) under free-living conditions, while wearing a blinded CGM sensor. Glucose levels will be continuously measured, and meal challenge sequence will be randomly assigned to each participant.

The study objectives are to:

  1. determine the within meal replicability of postprandial glucose response to a Ensure and White Rice meal challenges
  2. evaluate if a whole food meal challenge (White Rice) exhibits lower reliability and greater physiological variability (under the chewing vs. not chewing condition) in postprandial glucose response compared to a standardized liquid mixed meal tolerance test (Ensure)
  3. compare the postprandial average peak glucose response and 4 hour incremental area under the curve (iAUC) for the Ensure tolerance test, mountain dew tolerance test, White Rice, and typical breakfast.

These findings will inform the design of future studies and the potential use of CGM-based dietary challenges for early detection of metabolic risk.

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.
20

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.
  • Name: Nicole L Spartano, PhD
  • Phone Number: 315-415-2040
  • Email: spartano@bu.edu

Study Contact Backup

  • Name: Bahar Bakshi, MS
  • Phone Number: (315) 415-2040
  • Email: baharb@bu.edu

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:

  • Generally healthy
  • English speaking

Exclusion Criteria:

  • Prior diagnosis of diabetes or taking medications that influence glucose metabolism, such as insulin, glucocorticoids, or Glucagon-like peptide-1 (GLP-1) receptor agonists.
  • Taking hydroxyurea medication
  • Taking beyond the maximum dose of acetaminophen (4g/day)
  • Known food allergies or severe sensitivities to any study materials (dairy or soy)
  • Limited and non-readers
  • Cognitive impairment

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.
Experimental: Continuous glucose monitoring
Each participant will have a Dexcom G6 CGM sensor applied to the upper arm. The order of the six study meals will be randomly assigned.
Other: Six meal challenges
Two of the meal challenges will only be provided once: (1) a 20oz bottle of Mountain Dew (2) a "typical breakfast" that participants would eat normally. The other four challenges consist of two meal events that will each be repeated: (1) two 8-ounce bottles of Ensure® nutritional shake (2) one cup of microwaved white rice (microwaveable Minute brand Jasmine Rice cups). The rice challenge will be performed once with normal chewing and once by swallowing without chewing, while the Ensure challenge will be repeated the same way on both days.

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
Glycemic patterns from CGM
Time Frame: baseline, every 4 hours for 6 days
Beginning at baseline, a 4-hour incremental area under the glucose curve (iAUC) will be calculated using the trapezoidal method. Peak glucose will be defined as the maximum glucose excursion within the 4-hour window. Continuous glucose monitoring (CGM) CGM values are recorded every 5 minutes, so linear interpolation will be used to provide a CGM value every minute to line up with the ingestion time documented in the participant's log.
baseline, every 4 hours for 6 days

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
Fasting blood glucose levels
Time Frame: baseline, daily for 6 days
This outcome will be assessed from the CGM data recorded after a10 hour fast.
baseline, daily for 6 days
Post prandial glucose levels
Time Frame: baseline, daily for 6 days
This outcome will be assessed from the CGM data recorded daily 4 hours after a study meal.
baseline, daily for 6 days

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.
Boston University

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: Nicole L Spartano, PhD, BUCA School of Medicine, Endocrinology, Diabetes, Nutrition and Weight Management

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.
July 1, 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.
December 1, 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.
December 1, 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).
September 18, 2025

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.
December 8, 2025

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.
December 19, 2025

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 28, 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 27, 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

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.
  • H-46249

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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