As a photographer, I travel full time. And if at all possible, I stay in an 'Extended Day' Hotel. These hotels have kitchens which feature full size refrigerators. This allows me to shop as if I was home and make any meal I want. This includes a platter of fruit (usually melons) for breakfast. And all my favorite places to go out to eat all feature brocoli, my favorite health food.
Every different place I go I find either a place to do a cardio hike daily, or a large park to bike. Cardio daily is important to me.
It's easy to over-eat (and over-spend on food) on trips. And to be presented with crummy food choices on trips (ie: unhealthy and/or unpalatable choices). At times I have rebelled against this when I'm at a hotel with a frig...I'll just go to the grocery store and stock up on bread, deli meats and cheeses, fruit and veggies. Then I can eat the smaller meals (and frequent small snacks) that I prefer. Generally saving money and waste at the same time.