The problem with trying to go by the glycemic index is that each food still has to be computed regarding it's affect on the body!
Pick up a book (Holford Diet) or something similar that gives you the GLYCEMIC LOADING of each food. This already has the computations done, and shows the carbs (especially) as they really are.
I just can't be bothering with all that math when I'm HUNGRY!

(It's easy for EJ, as she's an economics master!)