Bring snacks: Bring healthy, packable snacks such as nuts, seeds, hard-boiled eggs, and protein bars when you travel.
At your destination: Stock up on healthy snacks at a nearby market. Request a mini-fridge you can stock yourself.
Request a special airline meal when available. Some airlines let you request gluten-free, vegetarian, or calorie-controlled meals. Make sure to place your request at least several days in advance.