1 day of shitty eating won’t hurt you (that much).
i’d bring some fruits (apples), and if you have the time (and the Grow!), then make yourself some protein bars to eat along the way
most people tend to sleep during those long flights. i dunno if you’re one of them, but if you are, you probably won’t have to worry about eating those 4-5 meals.
Bagels??? Low GI foods, Nuts, Apples, Peaches, Pears, Berries, A good MRP and a shaker cup, Beef jerky, Raw Veggies, Hard boiled Egg whites (You might get some strange looks from passengers) Good luck.
Definately bring a couple bottles of water. This will prevent you from dehydrating (this is a big plus on a long flight). Most of the airline (re. free) food sucks. Buy-on-Board isn’t too back, they have some good Salmon Salads. Otherwise you can buy ready to fly meals (Le Bon Pain is one of the better ones). Bring fruit, nuts and protein bars. Try and avoid the alcohol, will dehydrate you and make you feel worse in the end, beyond the hangover.
Honestly, from a space-saving standpoint, nothing beats protein powder. Just package it in one of those hefty one-zip bags and throw an extra scooper in there.
As far as 5-6 meals, you’ll be sitting at rest, so I doubt you’ll feel like eating that many times. I’d say 3-4. Maybe bring 2 real food meals and then have one meal Shake + dried fruit and the other meal shake + nuts.