GlycaemiaGlyCarbNCT05317429
Glycaemic Responses to Carbohydrate-rich Meals (GlyCarb)
A study testing A meal delivering 75 g of carbohydrate in people with Glycaemia, run by Quadram Institute Bioscience at 1 site in United Kingdom.
Trial summary
Carbohydrate-rich foods such as potatoes, bread, rice, pasta, breakfast cereals, biscuits and other snacks are a major component of the human diet. The effect of different carbohydrate-rich foods on blood sugar (glucose) levels after a meal varies between foods. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Glycaemia
- What is being tested?
- A meal delivering 75 g of carbohydrate
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 25 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 14 Feb 2022to 30 Jun 2028
- 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 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Men and women ≥ 18 years of age
- Have access to/own a smartphone or tablet or computer and are willing to use this with apps needed for the study
- BMI between 18 and 30 kg/m2 (calculated from self-reported height and weight)
- Fasted HbA1C < 42 mmol/mol (6.0%)
- Willing to consume study foods (study foods and ingredients are discussed during the study talk)
Who cannot join
- Smokers of tobacco-based cigarettes or electronic cigarettes (or stopped smoking less than 6 months ago)
- Gastro-intestinal disease/disorders e.g., Crohn's disease/ulcerative colitis
- Other medical conditions that are judged to affect the study outcome or which may compromise the well-being of the participant e.g., active cancer, haemophilia. This will be assessed on a case-by-case basis.
- Type 1 diabetes or insulin-dependent or non-insulin-dependent type 2 diabetes
- Active infection with COVID-19, unless they are willing to postpone the screening until after the end of the self-isolation period (10 days from test or symptoms).
- Prescribed and non-prescribed medications that may affect the study outcome or which may compromise the well-being of the participant e.g., warfarin, proton-pump inhibitors. This will be assessed on a case by-case-basis.
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- Dietary supplements that are judged to affect the study outcome unless the participant is willing to discontinue them for 4 weeks preceding the start of the study and for the duration of the study. This will be assessed on a case-by-case basis and includes protein supplements (shakes) or supplements that are not taken on a regular basis (on and off), particularly those containing ascorbic acid which may affect glucose readings.
- Any known allergy, intolerance, or sensitivity to any food products oradhesives (for CGM application).
- Those following a restrictive diet that may affect the study outcome (e.g., 5:2 diet) unless they are willing to suspend the diet for the duration of the study.
- Women who are, or have been pregnant, within the last 12 months or who are breast-feeding
- Parallel participation in another research project that involves dietary intervention.
- Any person related to or living with any member of the study team.
- Those who are part of the line manager/supervisory team of the Chief Investigator
- Lack of capacity to provide written informed consent.
- Clinical eligibility test results deemed by the CRF medical advisor to be indicative of a health problem which may compromise the well-being of the participant or which could affect the study outcome.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
About this study
Official title: Measuring Postprandial Glycaemic Responses to Carbohydrate-rich Meals Using a Standardised Remote Monitoring Protocol
Carbohydrate-rich foods such as potatoes, bread, rice, pasta, breakfast cereals, biscuits and other snacks are a major component of the human diet. The effect of different carbohydrate-rich foods on blood sugar (glucose) levels after a meal varies between foods. This is relevant to health because studies have shown that regular intake of carbohydrate foods that cause large increases in blood glucose levels after ingestion can be detrimental to metabolic health.
The aim of the GlyCarb study is to investigate how food structure influences postprandial glycaemic responses to carbohydrate foods.
Read more
This will be achieved through a series of acute postprandial studies (up to 5 studies), wherein healthy participants within each postprandial study consume a pair of carbohydrate-rich test meals while wearing a continuous glucose monitoring system (CGM).
Each postprandial study will use the same GlyCarb Remote standard protocol, where a randomised cross-over design is used to measure the glycaemic response to two carbohydrate-rich test meals, one "test" and one "control". Both meals will be matched by carbohydrate content, contain similar ingredients and have a similar physical appearance, but will differ in one key food property (e.g., altered food structure) to test its effect on postprandial glycaemia.
In each postprandial study, habitual dietary intake and body composition will be captured at baseline as part of the participant characterisation. Participants will consume two different carbohydrate-rich test meals twice, on separate occasions, in a randomly allocated order over a 10 to 14-day period of continuous glucose monitoring. Data from the continuous glucose monitors will be used to assess the postprandial glycaemic response to each carbohydrate food. The participants will be required to complete brief questionnaires designed to evaluate differences in palatability (taste, texture, portion size) and satiety amongst test meals. Study participant feedback will be requested at the end of the study and used to assess and improve future study procedures.
The GlyCarb study will enable new understanding of how food properties influence glycaemic responses to different types of carbohydrate foods. Ultimately, the findings will inform the rational design or reformulation of food products and diets to support a healthy glucose metabolism.
Read the detailed description
The overarching aim of this project is to investigate a wide range of carbohydrate rich test meals (from 'off the shelf' commercially available products, through to enriched, restructured and re-formulated food products) on postprandial glycaemic response in normo-glycaemic individuals.
The 'remote' study protocol has been designed to maintain social distancing and thereby reduce risk of COVID19 transmission between participants and researchers during the ongoing outbreak. It also makes excellent use of continuous glucose monitoring devices, which enable continuous recording of participant body sugar levels in 'free-living' conditions. At no point will the participant be required to attend a clinical research facility. Support from the study team to participants will be provided through virtual appointments.
The study population will be healthy participants. Participants will also need to have access to a smart phone to be used in conjunction with the CGM as well as for virtual study appointments (video call) and to complete online forms.
The precise test meals will vary from study to study, and will always need to meet a set standard with regard to microbiological safety, traceability and nutrient composition. As an extra precaution, participants with ANY food allergy will not be able to take part in the study. The meals will be well characterised and details of nutrient composition, ingredients, allergens etc. will be provided to participants prior to consent.
Informed consent - to ensure participants can make an informed decision as to whether or not they wish to take part on the trial they will be provided with a study specific PIS and invited to participate in an informal discussion about the study. Consent will be obtained by a member of staff who is GCP trained and experienced in conducting human intervention trials. In line with the 'remote' nature of the study, participants and study team members will be video and audio recorded during the consent procedure, with their permission. Hard copies of the consent form will also be initialled and signed by the participant and countersigned by the study team as written informed consent.
Risks/Burdens - (i) At the eligibility assessment a small blood sample is collected. Participants may feel a little discomfort on initial insertion of the needle or bruising at the site of venepuncture. Similarly, there may be some discomfort during finger prick testing. (ii) The CGM sensor may be secured by an adhesive 'plaster' which could cause irritation. Should this occur the CGM could be secured in place with an elastic support bandage such as tubigrip or similar.
iii) This study involves periods of fasting. Participants will be advised to drink water during the fasting period. All study sessions will be scheduled for the morning time to reduce the length of fast.
(iv) As part of the eligibility assessment it is possible that some test results are returned as abnormal. Abnormal blood and urine test results are reviewed by our medical doctor who advises whether inclusion, re-screen or exclusion is appropriate. In addition, copies of all test results (whether abnormal or not) will be sent to the participants GP.
Participants will complete a Food Frequency Questionnaire to capture the habitual diet as a baseline characteristic as well as measure fat and muscle mass using a smart scale.
Data protection and confidentiality - Participants will be assigned a unique code and a Quadram Institute Bioscience (QIB)-based email which will be used on all samples/data arising from a study. Paper documents containing identifiable information (e.g. consent forms) and coded information will be kept in locked cabinets at the QIB. The file linking the code with the participant will be kept separately. All documents will only be accessible to the members of the study team. All electronic data will be stored on a password protected shared file at the QIB and access will be limited to members of the study team.
- Conditions
- Glycaemia
- Being tested
- A meal delivering 75 g of carbohydrate
- Keywords
- Carbohydrates, Starch
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
A meal delivering 75 g of carbohydrateOther
The nature of the test meal will depend upon the research question being addressed and it is anticipated that the test meals may include (but are not limited to) the following:
(i) Re-structured, enriched, and/or reformulated or non-conventionally processed food products (ii) Model food matrices with different structures or types of carbohydrate e.g. soups with different viscosity.
| Study group | Role | What they receive |
|---|---|---|
| Treatment | Experimental | Carbohydrate-rich meal Receives: Other: A meal delivering 75 g of carbohydrate |
| Control | Active comparator | Carbohydrate-rich meal Receives: Other: A meal delivering 75 g of carbohydrate |
What is being measured
The primary outcome is the main question the study is designed to answer.
Fasting and postprandial glucose levels measured in interstitial fluid
Maximum rise in glucose concentration from fasted levels (iCmax)
Measured: 0-4 hours after the test meal
Secondary outcomes (11)
Glycaemic response indicators
Incremental area under the curve (iAUC) for the first peak
Measured: 2 to 4 hours after the test meal
Glycaemic response indicators
Incremental area under the curve (iAUC) between 0-120 min
Measured: 2 to 4 hours after the test meal
Glycaemic response indicators
Minimum glucose concentration (Cmin)
Measured: 2 to 4 hours after the test meal
Glycaemic response indicators
Time to reach glucose peak concentration (Tmax), time to reach minimum concentration (Tmin)
Measured: 2 to 4 hours after the test meal
Glycaemic response indicators
Time to reach minimum glucose concentration (Tmin)
Measured: 2 to 4 hours after the test meal
Glycaemic response indicators
Coefficient of variation (CV)
Measured: Over 14 days
Glycaemic response indicators
Time in Range (TIR)
Measured: Over 14 days
Glycaemic response indicators
Mean Amplitude Glucose Excursion (MAGE)
Measured: Over 14 days
Glycaemic response indicators
Mean of daily differences (MODD)
Measured: Over 14 days
Satiety
Online survey responses from participants.
Measured: Time 0 (before meal), 30 (after meal), 60, 120, 180 and 240 minutes after each test meal.
Palatability
Online survey responses from participants. Palatability scores (recorded once after each test meal), from 'Dislike Very Much' to 'Like Very Much'.
Measured: Once per day on intervention days, four times per study
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Apr 2022
- Study start14 Feb 2022
- Primary completion31 Mar 2028 (estimated)
- Study completion30 Jun 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for GlycaemiaStudies of the same condition, open and under way.
- 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
- Model description
- Randomised crossover study
- Masking
- Double blind
- Who is masked
- Investigator, Outcomes assessor
- Enrolment
- 25 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Quadram Institute Bioscience
- Sponsor type
- University, hospital or other
- Collaborators
- Norfolk and Norwich University Hospitals NHS Foundation Trust
- Responsible party
- Sponsor
- Investigators
- Cathrina Edwards, PhD, Principal investigator, Quadram Institute Bioscience
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05317429
- Sponsor's protocol ID
- QIB07/2020
- Acronym
- GlyCarb
- Status last verified
- Jul 2025
- First submitted
- 16 Feb 2022
- Last updated
- 24 Jul 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified individual participant data for primary and secondary outcome measures will be made available
Study at a glance
From the registry record, last updated by the sponsor on 24 Jul 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Measuring Postprandial Glycaemic Responses to Carbohydrate-rich Meals Using a Standardised Remote Monitoring Protocol
- ClinicalTrials.gov ID
- NCT05317429
- Acronym / sponsor ID
- GlyCarb / QIB07/2020
- Conditions
- Glycaemia
- Keywords
- Carbohydrates, Starch
- Study type
- Interventional
- Recruitment status
- Enrolling by invitation
- Enrolment
- 25 participants (estimated)
- Lead sponsor
- Quadram Institute BioscienceUniversity, hospital or other
- Collaborators
- Norfolk and Norwich University Hospitals NHS Foundation Trust
- Study start
- 14 Feb 2022 (actual)
- Primary completion
- 31 Mar 2028 (estimated)
- Study completion
- 30 Jun 2028 (estimated)
- First posted
- 7 Apr 2022 (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.
Carbohydrate-rich foods such as potatoes, bread, rice, pasta, breakfast cereals, biscuits and other snacks are a major component of the human diet. The effect of different carbohydrate-rich foods on blood sugar (glucose) levels after a meal varies between foods. This is relevant to health because studies have shown that regular intake of carbohydrate foods that cause large increases in blood glucose levels after ingestion can be detrimental to metabolic health.
The aim of the GlyCarb study is to investigate how food structure influences postprandial glycaemic responses to carbohydrate foods.
This will be achieved through a series of acute postprandial studies (up to 5 studies), wherein healthy participants within each postprandial study consume a pair of carbohydrate-rich test meals while wearing a continuous glucose monitoring system (CGM).
Each postprandial study will use the same GlyCarb Remote standard protocol, where a randomised cross-over design is used to measure the glycaemic response to two carbohydrate-rich test meals, one "test" and one "control". Both meals will be matched by carbohydrate content, contain similar ingredients and have a similar physical appearance, but will differ in one key food property (e.g., altered food structure) to test its effect on postprandial glycaemia.
In each postprandial study, habitual dietary intake and body composition will be captured at baseline as part of the participant characterisation. Participants will consume two different carbohydrate-rich test meals twice, on separate occasions, in a randomly allocated order over a 10 to 14-day period of continuous glucose monitoring. Data from the continuous glucose monitors will be used to assess the postprandial glycaemic response to each carbohydrate food. The participants will be required to complete brief questionnaires designed to evaluate differences in palatability (taste, texture, portion size) and satiety amongst test meals. Study participant feedback will be requested at the end of the study and used to assess and improve future study procedures.
The GlyCarb study will enable new understanding of how food properties influence glycaemic responses to different types of carbohydrate foods. Ultimately, the findings will inform the rational design or reformulation of food products and diets to support a healthy glucose metabolism.
Detailed description
The overarching aim of this project is to investigate a wide range of carbohydrate rich test meals (from 'off the shelf' commercially available products, through to enriched, restructured and re-formulated food products) on postprandial glycaemic response in normo-glycaemic individuals.
The 'remote' study protocol has been designed to maintain social distancing and thereby reduce risk of COVID19 transmission between participants and researchers during the ongoing outbreak. It also makes excellent use of continuous glucose monitoring devices, which enable continuous recording of participant body sugar levels in 'free-living' conditions. At no point will the participant be required to attend a clinical research facility. Support from the study team to participants will be provided through virtual appointments.
The study population will be healthy participants. Participants will also need to have access to a smart phone to be used in conjunction with the CGM as well as for virtual study appointments (video call) and to complete online forms.
The precise test meals will vary from study to study, and will always need to meet a set standard with regard to microbiological safety, traceability and nutrient composition. As an extra precaution, participants with ANY food allergy will not be able to take part in the study. The meals will be well characterised and details of nutrient composition, ingredients, allergens etc. will be provided to participants prior to consent.
Informed consent - to ensure participants can make an informed decision as to whether or not they wish to take part on the trial they will be provided with a study specific PIS and invited to participate in an informal discussion about the study. Consent will be obtained by a member of staff who is GCP trained and experienced in conducting human intervention trials. In line with the 'remote' nature of the study, participants and study team members will be video and audio recorded during the consent procedure, with their permission. Hard copies of the consent form will also be initialled and signed by the participant and countersigned by the study team as written informed consent.
Risks/Burdens - (i) At the eligibility assessment a small blood sample is collected. Participants may feel a little discomfort on initial insertion of the needle or bruising at the site of venepuncture. Similarly, there may be some discomfort during finger prick testing. (ii) The CGM sensor may be secured by an adhesive 'plaster' which could cause irritation. Should this occur the CGM could be secured in place with an elastic support bandage such as tubigrip or similar.
iii) This study involves periods of fasting. Participants will be advised to drink water during the fasting period. All study sessions will be scheduled for the morning time to reduce the length of fast.
(iv) As part of the eligibility assessment it is possible that some test results are returned as abnormal. Abnormal blood and urine test results are reviewed by our medical doctor who advises whether inclusion, re-screen or exclusion is appropriate. In addition, copies of all test results (whether abnormal or not) will be sent to the participants GP.
Participants will complete a Food Frequency Questionnaire to capture the habitual diet as a baseline characteristic as well as measure fat and muscle mass using a smart scale.
Data protection and confidentiality - Participants will be assigned a unique code and a Quadram Institute Bioscience (QIB)-based email which will be used on all samples/data arising from a study. Paper documents containing identifiable information (e.g. consent forms) and coded information will be kept in locked cabinets at the QIB. The file linking the code with the participant will be kept separately. All documents will only be accessible to the members of the study team. All electronic data will be stored on a password protected shared file at the QIB and access will be limited to members of the study team.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (investigator, outcomes assessor)
- Number of arms
- 2
- Model description
- Randomised crossover study
| Arm | Type | Receives |
|---|---|---|
| Treatment | Experimental | Other: A meal delivering 75 g of carbohydrateCarbohydrate-rich meal |
| Control | Active comparator | Other: A meal delivering 75 g of carbohydrateCarbohydrate-rich meal |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Men and women ≥ 18 years of age
- Have access to/own a smartphone or tablet or computer and are willing to use this with apps needed for the study
- BMI between 18 and 30 kg/m2 (calculated from self-reported height and weight)
- Fasted HbA1C < 42 mmol/mol (6.0%)
- Willing to consume study foods (study foods and ingredients are discussed during the study talk)
Key exclusion criteria (15 listed)
- Smokers of tobacco-based cigarettes or electronic cigarettes (or stopped smoking less than 6 months ago)
- Gastro-intestinal disease/disorders e.g., Crohn's disease/ulcerative colitis
- Other medical conditions that are judged to affect the study outcome or which may compromise the well-being of the participant e.g., active cancer, haemophilia. This will be assessed on a case-by-case basis.
- Type 1 diabetes or insulin-dependent or non-insulin-dependent type 2 diabetes
- Active infection with COVID-19, unless they are willing to postpone the screening until after the end of the self-isolation period (10 days from test or symptoms).
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 |
|---|---|---|
| A meal delivering 75 g of carbohydrateThe nature of the test meal will depend upon the research question being addressed and it is anticipated that the test meals may include (but are not limited to) the following: (i) Re-structured, enriched, and/or reformulated or non-conventionally processed food products (ii) Model food matrices with different structures or types of carbohydrate e.g. soups with different viscosity. | Other | Control, Treatment |
Primary outcome
Fasting and postprandial glucose levels measured in interstitial fluid
Time frame: 0-4 hours after the test meal
Maximum rise in glucose concentration from fasted levels (iCmax)
11 secondary outcomes
Glycaemic response indicators
Time frame: 2 to 4 hours after the test meal
Glycaemic response indicators
Time frame: 2 to 4 hours after the test meal
Glycaemic response indicators
Time frame: 2 to 4 hours after the test meal
Glycaemic response indicators
Time frame: 2 to 4 hours after the test meal
Glycaemic response indicators
Time frame: 2 to 4 hours after the test meal
Glycaemic response indicators
Time frame: Over 14 days
Glycaemic response indicators
Time frame: Over 14 days
Glycaemic response indicators
Time frame: Over 14 days
Glycaemic response indicators
Time frame: Over 14 days
Satiety
Time frame: Time 0 (before meal), 30 (after meal), 60, 120, 180 and 240 minutes after each test meal.
Palatability
Time frame: Once per day on intervention days, four times per study
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 24 Jul 2025.
- Individual participant dataSharing planned: Yes. De-identified individual participant data for primary and secondary outcome measures will be made available
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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.
Cathrina Edwards, PhD principal investigator
Quadram Institute Bioscience
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing A meal delivering 75 g of carbohydrate in people with Glycaemia, run by Quadram Institute Bioscience at 1 site in United Kingdom.
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 15 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: enrolling by invitation, as of the sponsor's last update on 24 Jul 2025. 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 Kingdom. 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?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Fasting and postprandial glucose levels measured in interstitial fluid (time frame: 0-4 hours after the test meal). 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 24 Jul 2025.