Glycemic
index rates foods according to how they affect your
glucose numbers. Many websites will let you look up foods to see the ratings.
So potatoes are worse than cauliflower, for example, because potatoes have alot of starch aka sugar aka carbs in them and would affect your glucose ratings more than cauliflower.
Many don't realize though that one food has multiple glycemic index ratings, according to how it is prepared.
Raw, boiled, baked, fried, steamed, etc.