I don't know a whole lot and what I do know is for type 1 diabeties, not sure if it's different for type 2. Basically some foods are considered "free" because they have no carbs, or too few to matter, in a serving. These foods are meat, nuts, vegetables, cheese. All fruits, grains, and beans have carbs. My neice needs to count all carbs for any given meal/snack, she has a target range of about 40 carbs per meal. I know she needs some carbs, just not a lot. Also protein somehow helps with keeping her blood sugar in line, so she eats meat for protein and because it has no carbs. Most non-meat protein sources have carbs, i.e. beans, so she tends to lean on meat for protein. She almost never has potatoes, rice, pasta, popcorn, cookies, cakes, candy. Also I think whole grains have more carbs then refined, whole wheat flour has more carbs then white flour. With them they don't seem to care as much about how healthy something is as long as the carbs are low. Personally I would prefer something healthy with more carbs then something not so healthy with less carbs. (example whole wheat bread over white bread).