Another thing to consider - when you are glycogen depleated (or starting to be), you don't get the same reaction from ingesting pure sugar that you do when you are just hungry. Even those who low carb (by choice, not because they have too) can eat simpler sugars when riding hard without adversely affecting blood sugar. Basically, your body uses it so quickly that your insulin does not have to 'rise' to accomodate it.

If you want to read more about this, The Paleo Diet for Athletes explains it much better than I can!