Foods with a high glycemic index are problematic, because the carbohydrates aren't needed, so the body releases the insulin to store them, blood sugar drops, and you get hungry again.
But it's very different when you are exercising. The carbs don't spike your blood sugar because they are conveyed directly to the muscles.
So, you want a small amount of carbs while you exercise on longer rides (say, longer than 90 minutes) - start at around 250 cal/hour. That will keep your blood sugar level, you will get better performance, and you won't be as hungry afterwards.