How is glycemic index defined?

Glycemic index (GI) is defined as a ranking of foods based on their acute glycemic impact, which refers to how quickly and how much a carbohydrate food raises blood glucose levels after consumption. Foods with a high glycemic index are rapidly digested and absorbed, leading to quick spikes in blood sugar, while those with a low glycemic index lead to slower, more gradual increases in blood glucose. This measurement is particularly important for individuals managing conditions such as diabetes, as it helps them choose foods that maintain stable blood glucose levels. Understanding the glycemic index not only aids in dietary planning but also serves as a tool in evaluating the effects of different carbohydrates on overall health and performance, especially in sports nutrition.

The other options do not accurately reflect the definition of glycemic index. While option A suggests the classification of foods based on sugar content, it overlooks the fundamental aspect of blood glucose response. Option B refers to calorie content instead of the specific glycemic response. Option D restricts the classification to carbohydrate foods, failing to encompass the full scope of the GI concept, which can apply to any food that contains carbohydrates, including those in mixed dishes.