I would recommend reading this article and forum topics related to fasted training.
Here is a good discussion that might answer your question.
When out for short hops 60 minutes or less I usually train without any food/water.
I was wondering if time out reaches two-three hours or the day is a double run, should the longest run be done fasted without water no food, or no food and sip plain water when needed?
Should the objective be to get the body used to little to no food or water?