I fly back and forth from the US to Egypt pretty regular. The leg between Egypt and Europe is only about 4.5 hours, Europe to US is 10 hours or so. This last time, flying British Air, I ordered the gluten free and, as somebody else described it, it was pretty bad. This time I'm flying Luthansia and I'll try thier gluten free, we shall see. I fly business class so overall the food is better than in cattle class.
Other than that, I usually will try to load up with almonds, etc in the lounge before boarding or bring my own jerky and almonds. I have never had any problems with security with items like that.
It also helps that I sleep well on the plane so if I decide not to eat, I just sleep through the meal.