Glycaemic testing

Glycaemic Testing and Research

At OxBCNH we conduct glycaemic index testing on behalf of clients from the health and food industry including manufacturers, retailers and suppliers ranging from small and medium-sized enterprises (SMEs) to multinational global organisations. 

What is GI?

The glycaemic index (GI) is a method of ranking foods on a scale of 1 to 100 according to the extent to which a food raises blood sugar levels after ingestion. The principle is that the slower the rate of carbohydrate absorption, the lower the rise of blood glucose level and the lower the GI value. A GI value ≥70 is considered high, a GI value 56-69 (inclusive) is medium and a GI value ≤55 is low (where the glucose standard = 100).

The glycaemic index (GI) method

How is GI measured?

Our GI tests involve a minimum of 10 healthy human participants, who are required to fast at least 12 hours before their test session. Prior to GI testing of a food, three glucose references are measured on three different occasions (50g or 25g of available carbohydrate portions, depending on the test food).

On the day of testing

  • Two fasted capillary blood samples are taken by trained personnel
  • The test food / glucose drink is consumed within 15 minutes
  • Capillary blood samples are taken every 15-30-minute intervals after consumption for two to three hours. 

From this, the area of the curve (AUC) is calculated that reflects the total rise in blood glucose levels after eating the test food or glucose drink. The final GI value of a food is the average of all participants.

The GI of the food is calculated:

GI measurement

Why Choose Brookes?

OxBCNH is the only GI testing centre in Europe recommended by the Glycemic Index Foundation. It is internationally renowned for its work on glycaemic index (GI) and we have published extensively in this area. Our procedure for GI testing is carried out in accordance with ISO 26642:2010 standards (ISO 26642:2010 Food Products - Determination of Glycaemic Index).


Contact us

Oxford Brookes Centre for Nutrition and Health

+44 (0) 1865 483297

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