The glycemic index predicts how much glucose you are going to absorb into your blood, compared to pure glucose. Brown bread has a lower glycemic index than table sugar.
The teaspoon equivalent makes it easier to see how much a food raises blood sugar. For example, 150 g boiled rice will raise blood sugar as much as 10 teaspoons of sugar will do. In the seventh part of our low carb for doctors series, Dr. Unwin explains the impact of specific starchy foods on blood-glucose levels.