I never remember to eat at cons, and even when I do, I don't eat enough.
I always bring water with me (refilling the bottle throughout the day), and usually a small bag of trail-mix or something, but due to convention center food being so expensive, I usually survive off of vending machine bags until getting back to the hotel room. D8
At Acen, I was modeling for a fashion show, which required the models to be there at 7/8am. Already, I hadn't gotten any sleep, but on top of that, none of us had eaten, so by the time I got back to the hotel room after seeing some panels I wanted to, I nearly passed out.
Another time I had a really bad experience with food was last year's AX. I had no money at all that day (really, I think I had like 75cents or less), and my friend had limited money on her as well, and she needed it to get back on the train. Luckily, we had discovered a small deli past the food trucks, and could afford salads, which was pretty good.
Upcoming Convention Of 2013-Anime Los Angeles 2014 RED Sniper, Festive!Sniper, Ellis