Loki, no need to eat I dont think, providing you have a good breakfast eg. porridge, three hours before, and maybe a Mars bar an hour before the race.
I usually take a few gulps of energy drink before the race, and try to avoid drinking stations because I can do without, but also it makes me gulp and cough as I am running if I try and drink.
anything further than a half marathon and I would drink once or twice.