Usually I pack some food for my 12 hour day and here is how a healthy balanced work day looks for me...
9:30 - Breakfast
green smoothie and a bowl of mesa cereal with almond milk
12:30- snack
almonds and mango banana smoothie
3:30- Before work lunch
egg sandwich, veggies and hummus
6:30 ( or when i get a chance to eat on flight)
Prob have salad and fruit
10:30
Green tea, brown rice pancake
Hopefully get home by 3am so I may bring little snack for my way home. extra veggies, or apple with cashew butter
I also drink about 1.5 - 3 litres of water per flight or else I feel really dehydrated the next morning. I also make sure days I fly a drink lots of water before I even get on the plane.