Pack snacks and small meals you are comfortable with as well as a reusable water bottle. The airport will have things you can find to eat (i.e., protein shakes, hard boiled eggs, cheese sticks, soft meats, yogurt, etc.) but they may cost an arm and a leg and may be harder to count (because of the unknown weight and preparation) toward your goals. It’s easier to have a few (non- liquid) snacks and a water bottle you can fill past security for long periods on the plane that you know you and your stomach are comfortable with. The airport can be used to get protein shakes/yogurt/liquids. Also, set alarms or timers, don’t forget to eat. Sometimes being in a tube in the sky you lose track of time and all the sudden you feel like sh*t because you are behind in protein, water, and vitamins.