The glycemic index (GI) measures the variation of the blood sugar level (glycemia) after the ingestion of a high-carbohydrate food. The reference food is glucose, with a GI of 100; the glycemic index scale is therefore graduated from 0 to 100. Eating high-IG foods triggers a dramatic surge in the blood glucose concentration, which in turn triggers a large release of insulin (that promotes the migration of glucose towards the adipocytes and its storing within them). After a few minutes, the glycemia plummets, and we feel pangs of hunger and tiredness… which urge us to snack on sugary foods, and so on. Unlike them, low-GI foods promote a more lasting satiety and do not promote fat storage. A glycemic index under 55 is low, between 55 and 70 it is medium, and over 70, high. A word of caution: some low-GI foods may also contain large amounts of saturated fats and/or omega-6 fatty acids. They are marked with a *.