Establishing the Glycaemic Index of Fruit Drinks Using Different Measurement Methodologies

May 6, 2026 updated by: Emma Greatorex Brooks, University of Bath

Study to Examine Glycaemic Responses to the Ingestion of Fruit Juices and Smoothies Using Different Measurement Methodologies.

Glycaemic responses to carbohydrates ingested as fruit sugars may vary depending on factors inherent to the fruit and the type of sugar. The aim of this project is to investigate the glycaemic responses to a range of commercially available fruit drinks and to establish the glycaemic index for each product relative to a glucose reference. Differences in recorded responses could also be influenced by the sample type (capillary blood vs interstitial fluid) and participant characteristics. Participants will ingest 8 test drinks including 5 different fruit drinks (OJ, AJ, S&B, ENERGISE, BLUE), each matched for carbohydrate to the glucose reference (CONTROL) which will be sampled two times, an additional sample of one of the smoothies (S&B) will also be replicated. Fingerstick capillary blood sampling alongside dual sited continuous glucose monitors (CGM) will measure glucose and lactate concentrations, subjective appetite sensations will also be recorded. The tests will follow best practice guidelines for glycaemic index testing. These data will provide insight into how differing formulations can alter the glycaemic responses to fruit drinks, and whether sampling technique can affect the interpretations of measurement.

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.

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.
11

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: Emma L Greatorex Brooks
  • Phone Number: +44 (0) 1225 388388
  • Email: elgb21@bath.ac.uk

Study Locations

  • United Kingdom
      • Bath, United Kingdom, BA2 7AY
        • Department for Health, University of Bath

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:

  • Age: 18-65 years
  • Body mass index 18-30 kg/m2

Exclusion Criteria:

  • diagnosis of any form of diabetes
  • intolerances or allergies to any of the study procedures (e.g. fructose/inulin intolerance)
  • Fructose malabsorption
  • Inborn errors of fructose metabolism (e.g. fructokinase deficiency, aldolase B deficiency, fructose-1,6-bisphosphatase deficiency)
  • pregnant or lactating
  • any condition that could introduce bias to the study (e.g. diagnoses of lipid disorders, including cardiovascular disease, or therapies that alter lipid or glucose metabolism, such as statins or niacin).

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.
Active Comparator: CONTROL
50 g glucose (55 g dextrose powder accounting for hydration) plus 641 mL water
Other: Fruit drink
Commercially available fruit drinks or smoothies
Active Comparator: REPLICATE CONTROL
50 g glucose (55 g dextrose powder accounting for hydration) plus 641 mL water
Other: Fruit drink
Commercially available fruit drinks or smoothies
Experimental: S&B
417 mL of commercially available "Strawberries & Bananas" fruit smoothie providing 50 g carbohydrate [strawberries (31%), apples, bananas (22%), white grapes, oranges, blackcurrants]. Plus 224 mL water to standardise volume
Other: Fruit drink
Commercially available fruit drinks or smoothies
Experimental: REPLICATE S&B
417 mL of commercially available "Strawberries & Bananas" fruit smoothie providing 50 g carbohydrate [strawberries (31%), apples, bananas (22%), white grapes, oranges, blackcurrants]. Plus 224 mL water to standardise volume
Other: Fruit drink
Commercially available fruit drinks or smoothies
Experimental: OJ
641 mL of commercially available "Smooth Orange Juice" providing 50 g of carbohydrate [100% oranges]
Other: Fruit drink
Commercially available fruit drinks or smoothies
Experimental: AJ
455 mL commercially available "Apple Juice" providing 50 g of carbohydrate [apples, ascorbic acid]. Plus 186 mL water to standardise volume
Other: Fruit drink
Commercially available fruit drinks or smoothies
Experimental: ENERGISE
417 mL of commercially available "Energise Super Smoothie" providing 50 g carbohydrate [apples (50%), red grapes, bananas, strawberries (10%), blackcurrants, sour cherries (3.3%), pressed beetroot, flax seeds (0.56%), guarana infusion (0.01%), vitamins B1, B2, B3, B6, C & E]. Plus 224 mL water to standardise volume
Other: Fruit drink
Commercially available fruit drinks or smoothies
Experimental: BLUE
521 mL of commercially available "Bolt from the Blue" juice drink providing 50 g carbohydrate [apple (66%), coconut water (18%), white grapes, white guava (5.2%), passion fruit, lime (0.87%), spirulina extract (0.81%) vitamins B1, B2, B3, B6, C & E]. Plus 120 mL water to standardise volume
Other: Fruit drink
Commercially available fruit drinks or smoothies

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
Glycaemic indices for 5 test drinks measured using capillary blood samples
Time Frame: 120 minutes
Glycaemic indices [2-hour incremental area under the glucose curve (mmol/L-1x120 minutes) for each of the 5 test drinks relative to mean value of control conditions (CONTROL, REPLICATE CONTROL), expressed as a percentage] in capillary blood samples
120 minutes

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
Glycaemic index of all conditions with capillary blood samples vs CGM
Time Frame: 120 minutes
The difference in glycaemic index [2-hour incremental area under the glucose curve (mmol/L-1x120 minutes) for 5 test drinks relative to mean control (CONTROL, REPLICATE CONTROL), expressed as a percentage] in capillary blood samples versus continuous glucose monitors.
120 minutes

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
Comparisons between conditions in glucose concentration in capillary samples
Time Frame: 120 minutes
Comparison of blood glucose concentration 2-hour incremental area under the curve (iAUC) min.mmol/L between test conditions
120 minutes
Comparisons between conditions in glucose concentration in capillary samples
Time Frame: 120 minutes
Comparison of postprandial peak concentration mmol/L of blood glucose between test conditions (Cmax)
120 minutes
Comparisons between conditions in glucose concentration in capillary samples
Time Frame: 120 minutes
Comparison of time to peak blood glucose concentration in minutes (Tmax) between test conditions
120 minutes
Comparisons between conditions in glucose concentration in capillary samples
Time Frame: 120 minutes
Comparison of blood glucose concentration mmol/L at 2 hours between test conditions
120 minutes
Comparisons between conditions in glucose concentration with CGM
Time Frame: 120 minutes
Comparison of glucose concentration 2-hour incremental area under the curve (iAUC) min.mmol/L between test conditions
120 minutes
Comparisons between conditions in glucose concentration with CGM
Time Frame: 120 minutes
Comparison of postprandial peak concentration mmol/L of glucose between test conditions (Cmax)
120 minutes
Comparisons between conditions in glucose concentration with CGM
Time Frame: 120 minutes
Comparison of time to peak glucose concentration in minutes (Tmax) between test conditions
120 minutes
Comparisons between conditions in glucose concentration with CGM
Time Frame: 120 minutes
Comparison of glucose concentration mmol/L at 2 hours between test conditions
120 minutes
Comparisons between conditions in lactate concentration in capillary samples
Time Frame: 120 minutes
Comparison of blood lactate concentration 2-hour incremental area under the curve (iAUC) min.mmol/L between test conditions
120 minutes
Comparisons between conditions in lactate concentration in capillary samples
Time Frame: 120 minutes
Comparison of postprandial peak concentration mmol/L of blood lactate between test conditions (Cmax)
120 minutes
Comparisons between conditions in lactate concentration in capillary samples
Time Frame: 120 minutes
Comparison of time to peak blood lactate concentration in minutes (Tmax) between test conditions
120 minutes
Comparisons between conditions in lactate concentration in capillary samples
Time Frame: 120 minutes
Comparison of blood lactate concentration mmol/L at 2 hours between test conditions
120 minutes
Comparisons between conditions of appetite ratings
Time Frame: 120 minutes
Comparison of subjective appetite sensations assessed with visual analogue scales (2-hour area under the curve min.mmVAS)
120 minutes
Comparisons between individuals
Time Frame: 120 minutes
Comparison of Postprandial lactate concentration min.mmol/L between individuals 2-hour incremental area under curve (iAUC)
120 minutes
Comparisons between individuals
Time Frame: 120 minutes
Comparison of Postprandial glucose concentration min.mmol/L between individuals 2-hour incremental area under curve (iAUC)
120 minutes
Comparisons between individuals
Time Frame: 120 minutes
Comparison of Appetite rating responses min.mmVAS between individuals 2-hour area under curve (AUC)
120 minutes
Comparisons within individuals
Time Frame: 120 minutes
Comparison within individuals of interstitial glucose concentrations measurements from continuous glucose monitors on left and right arms.
120 minutes

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 Bath

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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.
March 13, 2025

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 9, 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 9, 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).
February 28, 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.
March 20, 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.
March 27, 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.
May 11, 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 6, 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

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.
  • 7134-9931

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified data will be made available open access on the University of Bath Research Data Archive (RDA) at the point of publication in a peer-reviewed journal.

IPD Sharing Time Frame

These will become available at the point of publication permanently

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

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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