It's tough. I used to fly over to Kuwait, etc... for the military from Baltimore all the time. If you bring tuna the flight attendants are gonna want to kill you and and so is anyone within a few rows of you. I used to cut up chicken into strips, bag em and carry on. They keep well and they don't stink plus you can eat with your fingers and don't look like a cave man. I also brought brown rice in a ziplock baggie, raw veggies, almonds, and some hard boiled eggs. Everything keeps pretty well. I actually prefer my brown rice chilled so I was good to go with that. Get a little soft sided cooler bag and you should have enough to hold you over for the flight.