I can't eat very much before a gig because I sing. It really affects my breathing, so a small bite to eat about 6pm.
I'll finish my dinner when I get home, usually it's a chilli.
When I was doing gigs away from home (with the Police tribute) it was quite awkward. I often didnt eat at all before the gig but there was always good snacks afterwards back at the hotel. Cold meats like salami, olives, pork pie, crisps and red wine