Glycaemic Index of Foods in Healthy Volunteers (GI)

Glycaemic Index Testing of Carbohydrate Containing Foods Using a Standardised Method

The objective of this study is to assess the effect that dietary carbohydrates have on blood sugar by measuring the glycaemic index. The glycaemic index is a comparison between the effect of equal amounts of carbohydrate from a test food compared to a standard (in this case glucose) on blood sugar.

Different foods that contain different carbohydrates have different effects on blood sugars. This is of interest as a number of studies have shown that the level of sugar in the blood after a meal relates directly to the risk of developing heart disease and diabetes. The aim of collecting this data is to be able to give advice to people about the carbohydrates they eat to reduce the risk of diabetes and heart disease.

Study Overview

• Status: Recruiting
• Conditions: Healthy
• Intervention / Treatment: Dietary supplement: food consumption

Detailed Description

The study is a randomized cross-over controlled trial: the order of the test foods will be randomized by an independent internet-based program; each participant will be asked to consume all the products; the test food will be compared with a control (in this case 50g glucose).

Suitable subjects will be invited for a screening visit to check for eligibility criteria. Body weight and height measurements will be taken as well as a standard biochemical and haematological screen. If they are eligible and willing to take part, volunteers will be entered into a database and contacted when a GI test becomes available. Volunteers may take part in more than one GI testing up to a maximum of 40 visits per year. Volunteers may withdraw from the database or the study at any time without giving any reason.

Subjects will be asked to come for a set amount of visits for each GI test depending on the number of product that need to be tested (minimum 3 maximum 12 visits for each testing). The volunteers will be informed of the number of visits before they enter the GI testing. For each visit, subjects are tested in the morning after a 10-12h overnight fast.

Three fasting blood samples are taken (-5, -3, -1) 2 minutes apart after which subjects consume the test meal or reference food at an even rate over 15 min. All subjects are asked to record the time it takes in minutes to consume the test food/reference. Further blood samples are taken at 15, 30, 31, 32, 45, 60, 90 and 120 min after the beginning of the meal. The test meal and reference food should be consumed with a 250ml drink of water. This remains constant for each of the tests in the series.

Blood is obtained by finger-pricking using disposable Unistix needles. In previous studies, capillary blood has yielded less between-subject variation in GI. Instant glucose analysers will be used.

• Study Type: Interventional
• Enrollment (Estimated): 20
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Gary Frost, BSc SRD PhD; Phone Number: 020 8383 8037; Email: g.frost@imperial.ac.uk

Study Locations

• United Kingdom
  • London, United Kingdom, W12 0HS
    • Recruiting
    • NIHR/Wellcome Trust Imperial CRF
    • Contact: Jeannette Davies; Phone Number: 02083838070; Email: Imperial.CRF@imperial.nhs.uk
    • Principal Investigator: Gary Frost, BSc SRD PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• BMI 18.5-27 kg/m2
• age 18-65 years
• healthy

Exclusion Criteria:

• diabetes
• chronic disease
• glucose impairment
• pregnancy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: food consumption: control; The control product will be 50g glucose powder dissolved in 250ml of water	Dietary supplement: food consumption; Reference food The reference food is 50 g glucose powder dissolved in 250ml water Test foods The test foods are prepared according to manufacturer's instructions, representing the food as normally consumed. The test foods are consumed once only on separate occasions as a portion providing 50g of available carbohydrate. Breakfast cereals should be consumed with 150 ml milk which is additional to the 50 g available carbohydrate in the cereal. In testing breakfast cereals, the reference food must also be consumed with an additional 150 ml milk.
Active Comparator: food consumption: product; The test food will provide 50g of available carbohydrate	Dietary supplement: food consumption; Reference food The reference food is 50 g glucose powder dissolved in 250ml water Test foods The test foods are prepared according to manufacturer's instructions, representing the food as normally consumed. The test foods are consumed once only on separate occasions as a portion providing 50g of available carbohydrate. Breakfast cereals should be consumed with 150 ml milk which is additional to the 50 g available carbohydrate in the cereal. In testing breakfast cereals, the reference food must also be consumed with an additional 150 ml milk.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
glycaemic index	1-2 months depending on product

Collaborators and Investigators

• Sponsor: Imperial College London
• Investigators: Principal Investigator: Gary Frost, BSc SRD PhD, Imperial College London

Study record dates

Study Major Dates

• Study Start (Actual): June 1, 2013
• Primary Completion (Estimated): March 1, 2025
• Study Completion (Estimated): March 1, 2025

Study Registration Dates

• First Submitted: April 12, 2013
• First Submitted That Met QC Criteria: April 16, 2013
• First Posted (Estimated): April 17, 2013

Study Record Updates

• Last Update Posted (Actual): August 14, 2023
• Last Update Submitted That Met QC Criteria: August 10, 2023
• Last Verified: August 1, 2023

More Information

Terms related to this study

• Keywords: glycaemic index; glucose response
• Other Study ID Numbers: 13HH0549

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