ObesityNCT06223555
Variability In Mixed Meal Tests: Fixed Versus Adjusted to Energy Needs Caloric Dose
A study testing Fixed Mixed Meal Test and Adjusted Mixed Meal Test in people with Obesity and Healthy Volunteer, run by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) at 1 site in United States.
Trial summary
Background: Researchers use mixed meal tolerance tests (MMTTs) to look at how people s bodies respond to eating a meal. However, researchers do not agree on how to decide the number of calories to give in each meal. Read more about this study
- Who is it for?
- Ages 18 to 99 yearsHealthy volunteers can take part
- Conditions the study is for
- Obesity, Healthy Volunteer
- What is being tested?
- Fixed Mixed Meal Test and Adjusted Mixed Meal Test
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 79 participants
- Where
- 1 siteUnited States
- Study dates
- 23 Aug 2024to 31 Dec 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 99 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- In order to be eligible to participate in this study, an individual must meet all of the following criteria:
- Provision of signed and dated informed consent form.
- Agreement to adhere to Lifestyle Considerations throughout study duration.
- Males and females; Age >= 18years
- Healthy, as determined by medical history, physical examination, and laboratory tests.
Who cannot join
- An individual who meets any of the following criteria will be excluded from participation in this
- study:
- Current use of medications, dietary supplements, or alternative therapies known to alter energy metabolism.
- Fasting plasma glucose >= 126 mg/dL
- Type I or Type II Diabetes Mellitus by self-report.
- Hematologic disorders including significant anemia (male hemoglobin < 13.0 g/dL or female hemoglobin < 11.0 g/dL)
Show all 14Show fewer
- Current pregnancy, pregnancy within the past 6 months or currently lactating
- History or self-report of gastrointestinal disease, including inflammatory bowel diseases (e.g. Chron s disease and ulcerative colitis), malabsorption syndromes (e.g. celiac disease), gastric ulcer (active) which may alter metabolism or absorption of study food by self-report
- Evidence of alcohol abuse as defined by an 8-point score on the Alcohol consumption screening AUDIT questionnaire in adults.
- Participants who report taking large doses of acetaminophen (> 3 grams daily) who cannot stop acetaminophen 24 hours prior to and following the meal tests will be excluded from the study.
- Inability to consume provided food based on a food allergy or intolerance.
- Conditions not specifically mentioned above may serve as criteria for exclusion at the discretion of the investigators.
- Any disorder, unwillingness, or inability not covered by any other exclusion criteria which, in the investigator s and/or team s opinion, jeopardizes the safety of the participant or others or would interfere with adherence to the protocol (such as claustrophobia).
- Conditions not specifically mentioned above may serve as criteria for exclusion at the discretion of the investigators.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
NIDDK, Phoenix
Phoenix, Arizona, 85014
Susi Votruba, Ph.D., 602-200-5336, votrubas@niddk.nih.gov
About this study
Background:
Researchers use mixed meal tolerance tests (MMTTs) to look at how people s bodies respond to eating a meal. However, researchers do not agree on how to decide the number of calories to give in each meal. Some use fixed meals, which are the same size for everyone, and some use adjusted meals, based on the size of the person s body. Researchers want to know which MMTT is best to use for future research.
Read more
Objective:
To learn how fixed vs adjusted meals affect blood glucose levels in healthy people.
Eligibility:
Healthy people aged 18 years or older.
Design:
Participants will have 3 or 4 clinic visits of up to 8 hours in 8 weeks.
Participants will have baseline tests:
Their height, weight, and waist size will be measured.
They will have an oral glucose tolerance test: A needle attached to a tube (IV) will be inserted into a vein in the arm. They will have a sugary drink. Blood samples will be taken from the tube at intervals up to 3 hours after the drink.
They will have a body scan.
Participants will have 2 MMTT visits. One will include a fixed meal and one will include an adjusted meal. They will have tests at both visits:
Resting metabolic rate: A clear hood will be placed over the participant s head while they rest for 20 minutes. This will measure the oxygen they breathe in and out.
MMTT. Participants will have 5 minutes to drink a liquid meal. Blood samples will be taken at intervals for the next 4 hours....
Read the detailed description
Study Description:
This study will be an outpatient study completed in 3-4 separate visits. We will compare two methods of dosing (fixed and adjusted) a mixed meal tolerance test (MMTT) to determine which results in greater physiological variability in hormone response. Ultimately, the goal is to determine which method of dosing is more appropriate in a research setting.
Objectives:
Primary Objective:
To determine whether an adjusted energy dose MMTT or a fixed dosed meal will result in greater variability in glucose area under the curve (AUC) within the same participants across a range of BMIs.
Secondary Objectives:
To determine whether baseline body composition, blood parameters (lipids, hormones, etc), and resting metabolic rate are associated with MMTT responses and whether this association is moderated by MMTT condition (fixed vs. adjusted).
Endpoints:
Primary Endpoint: Glucose area under the curve (AUC)
Secondary Endpoints: Area under the curve (AUC), incremental area under the curve (iAUC), value and timing of the absolute maximum (peak), value and timing of the inflection point after the absolute maximum value, value and timing of the maximum rate of incline, value and timing of the maximum rate of decline, total number of critical points with body composition, blood parameters, and resting metabolic rate as predictors.
- Conditions
- Obesity, Healthy Volunteer
- Being tested
- Fixed Mixed Meal Test, Adjusted Mixed Meal Test
- Keywords
- Healthy Volunteer, Obesity, Body Composition, Diet, Mixed Meal Test, Glucose
- Medical subject headings
- Obesity
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Fixed Mixed Meal TestOther
a FIXED dose meal that will be 900 kcal of a liquid meal
Adjusted Mixed Meal TestOther
a body weight ADJUSTED dose liquid meal.
(30% of total daily energy requirements)
| Study group | Role | What they receive |
|---|---|---|
| 1 | Active comparator | Fixed Mixed Meal Test Receives: Other: Fixed Mixed Meal Test |
| 2 | Active comparator | Adjusted Mixed Meal Test Receives: Other: Adjusted Mixed Meal Test |
What is being measured
The primary outcome is the main question the study is designed to answer.
To determine whether an adjusted energy dose MMTTor a fixed dosed meal will result in greater variability in glucose area under the curve (AUC) within the same participants across a range of BMIs.
Glucose AUC associated with MMTT conditions (fixed vs. adjusted).
Measured: Baseline, Visit 3/4
Secondary outcomes (3)
Body Composition
Change in energy expenditure associated with MMTT conditions (fixed vs. adjusted).
Measured: Baseline, Visit 3/4
Resting Metabolic Rate
Change in energy expenditure associated with MMTT conditions (fixed vs. adjusted).
Measured: Baseline, Visit 3/4
Lipids
Change in energy expenditure associated with MMTT conditions (fixed vs. adjusted).
Measured: Baseline, Visit 3/4
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Jan 2024
- Study start23 Aug 2024
- Primary completion30 Jun 2027 (estimated)
- Study completion31 Dec 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ObesityStudies of the same condition, open and under way.
- More trials run by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)The sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 79 participants (estimated)
Sponsor and investigators
- Sponsor type
- US National Institutes of Health
- Responsible party
- Sponsor
- Investigators
- Susanne M Votruba, Ph.D., Principal investigator, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06223555
- Sponsor's protocol ID
- 10001707
- Other IDs
- 001707-DK
- Status last verified
- 16 Sep 2026
- First submitted
- 24 Jan 2024
- Last updated
- 21 Sep 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 21 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Variability In Mixed Meal Tests: Fixed Versus Adjusted to Energy Needs Caloric Dose
- ClinicalTrials.gov ID
- NCT06223555
- Acronym / sponsor ID
- 10001707
- Conditions
- Obesity, Healthy Volunteer
- Keywords
- Healthy Volunteer, Obesity, Body Composition, Diet, Mixed Meal Test, Glucose
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 79 participants (estimated)
- Lead sponsor
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)US National Institutes of Health
- Study start
- 23 Aug 2024 (actual)
- Primary completion
- 30 Jun 2027 (estimated)
- Study completion
- 31 Dec 2027 (estimated)
- First posted
- 25 Jan 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Background:
Researchers use mixed meal tolerance tests (MMTTs) to look at how people s bodies respond to eating a meal. However, researchers do not agree on how to decide the number of calories to give in each meal. Some use fixed meals, which are the same size for everyone, and some use adjusted meals, based on the size of the person s body. Researchers want to know which MMTT is best to use for future research.
Objective:
To learn how fixed vs adjusted meals affect blood glucose levels in healthy people.
Eligibility:
Healthy people aged 18 years or older.
Design:
Participants will have 3 or 4 clinic visits of up to 8 hours in 8 weeks.
Participants will have baseline tests:
Their height, weight, and waist size will be measured.
They will have an oral glucose tolerance test: A needle attached to a tube (IV) will be inserted into a vein in the arm. They will have a sugary drink. Blood samples will be taken from the tube at intervals up to 3 hours after the drink.
They will have a body scan.
Participants will have 2 MMTT visits. One will include a fixed meal and one will include an adjusted meal. They will have tests at both visits:
Resting metabolic rate: A clear hood will be placed over the participant s head while they rest for 20 minutes. This will measure the oxygen they breathe in and out.
MMTT. Participants will have 5 minutes to drink a liquid meal. Blood samples will be taken at intervals for the next 4 hours....
Detailed description
Study Description:
This study will be an outpatient study completed in 3-4 separate visits. We will compare two methods of dosing (fixed and adjusted) a mixed meal tolerance test (MMTT) to determine which results in greater physiological variability in hormone response. Ultimately, the goal is to determine which method of dosing is more appropriate in a research setting.
Objectives:
Primary Objective:
To determine whether an adjusted energy dose MMTT or a fixed dosed meal will result in greater variability in glucose area under the curve (AUC) within the same participants across a range of BMIs.
Secondary Objectives:
To determine whether baseline body composition, blood parameters (lipids, hormones, etc), and resting metabolic rate are associated with MMTT responses and whether this association is moderated by MMTT condition (fixed vs. adjusted).
Endpoints:
Primary Endpoint: Glucose area under the curve (AUC)
Secondary Endpoints: Area under the curve (AUC), incremental area under the curve (iAUC), value and timing of the absolute maximum (peak), value and timing of the inflection point after the absolute maximum value, value and timing of the maximum rate of incline, value and timing of the maximum rate of decline, total number of critical points with body composition, blood parameters, and resting metabolic rate as predictors.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| 1 | Active comparator | Other: Fixed Mixed Meal TestFixed Mixed Meal Test |
| 2 | Active comparator | Other: Adjusted Mixed Meal TestAdjusted Mixed Meal Test |
Who may qualify
- Ages
- 18 to 99 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- In order to be eligible to participate in this study, an individual must meet all of the following criteria:
- Provision of signed and dated informed consent form.
- Agreement to adhere to Lifestyle Considerations throughout study duration.
- Males and females; Age >= 18years
- Healthy, as determined by medical history, physical examination, and laboratory tests.
Key exclusion criteria (14 listed)
- An individual who meets any of the following criteria will be excluded from participation in this
- Current use of medications, dietary supplements, or alternative therapies known to alter energy metabolism.
- Fasting plasma glucose >= 126 mg/dL
- Type I or Type II Diabetes Mellitus by self-report.
- Hematologic disorders including significant anemia (male hemoglobin < 13.0 g/dL or female hemoglobin < 11.0 g/dL)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Fixed Mixed Meal Testa FIXED dose meal that will be 900 kcal of a liquid meal | Other | 1 |
| Adjusted Mixed Meal Testa body weight ADJUSTED dose liquid meal. (30% of total daily energy requirements) | Other | 2 |
Primary outcome
To determine whether an adjusted energy dose MMTTor a fixed dosed meal will result in greater variability in glucose area under the curve (AUC) within the same participants across a range of BMIs.
Time frame: Baseline, Visit 3/4
Glucose AUC associated with MMTT conditions (fixed vs. adjusted).
3 secondary outcomes
Body Composition
Time frame: Baseline, Visit 3/4
Resting Metabolic Rate
Time frame: Baseline, Visit 3/4
Lipids
Time frame: Baseline, Visit 3/4
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Sep 2026.
- NIH Clinical Center Detailed Web PageLink provided by the sponsor.
- Individual participant dataSharing planned: No
Related trials for Obesity
Not yet recruiting
Transcutaneous Auricular Vagus Nerve Stimulation Combined With Lifestyle Intervention for Visceral Fat Reduction in Adults With Overweight or Obesity
Overweight, Obesity
Not yet recruitingObservational study
Assessing the Impact of Perceptions of Unpredictability on Objective Measures of Food Consumption and Metabolism
Healthy Volunteer, Obestity
RecruitingPhase 1/2
HS235 Study in Overweight and Obese Participants With Combined Pre and Post-Capillary Pulmonary Hypertension Due to Heart Failure With Preserved Ejection Fraction
Pulmonary Hypertension, Heart Failure With Preserved Ejection Fraction
Not yet recruitingPhase 3
ELEVATE-LIVER: A Study to Test Whether Survodutide Helps Improve Heart Structure and Function in People With Overweight or Obesity and Fatty Liver Disease
Obesity, Metabolic Dysfunction-associated Steatotic Liver Disease
Not yet recruitingObservational study
A Natural History of Genetic and Environmental Predictors of Pubertal Timing Among Youth With Obesity
Obesity
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Susanne M Votruba, Ph.D. principal investigator
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Fixed Mixed Meal Test and Adjusted Mixed Meal Test in people with Obesity and Healthy Volunteer, run by National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 14 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 21 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Susanne M Votruba, Ph.D. ((602) 200-5336, votrubas@mail.nih.gov), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
To determine whether an adjusted energy dose MMTTor a fixed dosed meal will result in greater variability in glucose area under the curve (AUC) within the same participants across a range of BMIs. (time frame: Baseline, Visit 3/4). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Sep 2026.