Explain about the Glycemic Index (GI)?

In the previous sections, we have studied that some carbohydrates are rapidly digested and absorbed, some are digested slowly while some are not digested at all. Thus, it is obvious that different carbohydrates will raise blood glucose levels to a different extent. The ability of carbohydrates to raise blood glucose is referred to as "Glycemic Index" (GI).

Table: Glycemic indices of some foods

GI is a quantitative assessment of foods based on post prandial blood glucose response (i.e. blood glucose level after a meal) expressed as a 'percentage of the response to an equivalent carbohydrate portion of a reference food'. The reference food is white bread with a GI set at 100. Glycemic indices of some foods are given in Table 3.4. Here you can see 2 columns indicating GI. In the first one, the reference food is white bread (Wb), while the second column has glucose (g) as its reference food with a GI of 100.