which fruit shouldn't be consumed by a diabetic person?

Well, as a Insulin Diabetic myself I know there are certain medications that are effected more from some of the Fruits you might eat, and then there are some fruits out there that will raise our BG more than others will as well. One of the worst ones out there that will spike your BG is Oranges. These are very high on the Glycemic index. One of the lower ones believe it or not is grapefruit. So you might need to check on of the sites online to find out just how much is in what, and experiment with some of them and see what they do for you.