A glycemic index diet is an eating plan based on how foods affect your blood sugar level.The glycemic index is a system of assigning a number to carbohydrate-containing foods according to how much each food increases blood sugar. The glycemic index itself is not a diet plan but one of various tools - such as calorie counting or carbohydrate counting - for guiding food choices.The term "glycemic index diet" usually refers to a specific diet plan that...