If I run first thing in the morning then I won't eat anything before. It takes me a very long time to digest food and I feel anything I had even 2 hrs before a workout. If I run after work in the evening (5:30/6ish) I will stop eating at 4:30, but usually don't have any snacks that late.
Not sure what is best for you but I personally can't eat a meal right before I run. I know plenty of people who can, but I just can't. I've never really ran farther than 10k at one time, so not sure how it would affect me at longer distances.