How can the GI be relevant when people differ in their blood glucose responses to foods?
The GI reflects the relative ranking of different foods, irrespective of an individual s unique blood glucose profile. When a food s GI is tested, the response for each subject is compared with their response to a standard food (usually glucose, but sometimes white bread is used). Their blood glucose response to the standard is said to be 100. For example, if the blood glucose response of a person to one food is exactly half of their response to glucose, then the GI of that food is 50. Most subjects will fall within the same range, especially on repeated testing.
