JENNIE BRAND-MILLER: It's a horrible name. We shorten it to GI. And what it is, it's something to do with carbohydrate foods. So think of breakfast cereal and bread and rice and pasta. And what it's doing is giving us a measure of how much that carbohydrate food is raising our blood sugar levels when we eat them. So we have a score from zero to 100. And the higher the score, the higher the blood glucose or blood sugar goes when we eat those foods.