Glycaemic Index of Foods in Healthy Volunteers (GI)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details. Identifier: NCT01833689
Recruitment Status : Recruiting
First Posted : April 17, 2013
Last Update Posted : September 1, 2016
Information provided by (Responsible Party):
Imperial College London

April 12, 2013
April 17, 2013
September 1, 2016
June 2013
March 2023   (Final data collection date for primary outcome measure)
glycaemic index [ Time Frame: 1-2 months depending on product ]
Same as current
Complete list of historical versions of study NCT01833689 on Archive Site
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Glycaemic Index of Foods in Healthy Volunteers
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.

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.

Not Applicable
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
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.

  • Placebo Comparator: food consumption: control
    The control product will be 50g glucose powder dissolved in 250ml of water
    Intervention: Dietary Supplement: food consumption
  • Active Comparator: food consumption: product
    The test food will provide 50g of available carbohydrate
    Intervention: Dietary Supplement: food consumption
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*   Includes publications given by the data provider as well as publications identified by Identifier (NCT Number) in Medline.
Same as current
March 2023
March 2023   (Final data collection date for primary outcome measure)

Inclusion Criteria:

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

Exclusion Criteria:

  • diabetes
  • chronic disease
  • glucose impairment
  • pregnancy
Sexes Eligible for Study: All
18 Years to 65 Years   (Adult, Older Adult)
Contact: Gary Frost, BSc SRD PhD 020 8383 8037
United Kingdom
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Imperial College London
Imperial College London
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Principal Investigator: Gary Frost, BSc SRD PhD Imperial College London
Imperial College London
August 2016

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP