The idea does pose its challenges and it can take some work, but it can be done. When i go on a road trip I love to pack up a cooler and take my favorite foods that of course can be eaten on the road with me. I go to the deli at a grocery store in whatever town I happen to be in and stock up when needed.
Flying can be a bit of a different challenge, you can't take liquids so you are forced to make the better of the choices while at the airport or on the plane.
Hotel food may not be the best choice either, believe me from first hand experience, I recently had a house fire and lived at a hotel for 3 months, just moved back home this last week. I could have eaten their breakfast everyday, but it was not the best of healthy food choices although i did eat the yogurt, an occasional apple they offered and sometimes the oatmeal.
In recognition of the growing obesity epidemic, most fast-food restaurants are now offering healthier choices. Broiled or baked chicken dishes, vegetables, and salads are usually the best options. Pretty soon, many of these restaurants will be required to post calorie counts for all their menu items, which will most likely help people manage their weight and eat healthier.
We have to make it a point to pick the healthier of the meals that are offered, I don't know about you but i am ravenous when I travel, so I have to be careful, its very easy to gain 10 pounds before you get back home.