I travel for work and I always bring a cooler with an ice pack. Usually bring protein shakes, bottled waters and some easy to transport snacks (cheese, boiled egg, nuts, etc). Sometimes I make a grown-up version of lunchables in plastic divided containers. Just put some cheese, deli meat, veggies, fruit, etc in them. The cooler also comes in handy when I eat at a restaurant because my portions are so small that I always have leftovers!