The best idea is to eat dinner before the parks shut down.
IOA closes at 5pm, USF at 6pm.
At 6pm, you can go to the Stay and Scream area and start with the houses Wax and Ghosttown. There's really not much to eat in this area. The stay and scream area on the IOA side is Circus McGurkus and The Diner, so you could eat there.
The best idea, is to visit the parks early in the morning, go back to your hotel, take a nap, then come back to USF at 05:00pm, having something to eat. At 6pm, you can head to the Stay and Scream area of USF. There's plenty of drink stands and bars, but you really won't have time to sit down and eat if you wanna get thru the houses quickly.
Another plan, is to stay in the IOA side, do Disorientorium first, then walk to the USF side thru the Corn Field to do Wax and Ghosttown.
You'll really be hungry after the event. I had pizza in my hotel room. The TGIF across the street from the parking garage also stays open late.