GI is a number assigned to carbohydrate-containing foods that describes their effect on your blood glucose level after eating them. Not surprisingly, eating straight glucose gives a GI of 100. In general, the more processed, fiberless, and sweetened it is, the higher GI it will have. Why do you care? Well, because high GI foods are associated with increased risk of Diabetes, Coronary Artery Disease, Macular Degeneration,Obesity and Cancer. Yuck. Lower GI foods (>55) – you know what they are: REAL and FRESH foods,vegetables, fresh fruits, whole grains, stuff that takes some work to digest – those are the ones to eat. Avoid the white processed crap. From Dr. Andrew Weil: his response.