It would be very surprising if you consumed any fruits or vegetables, whole grains or lowfat dairy products. Of course, maybe for one day, this really wouldn't be a big problem. But, if you'd like to at least try to maintain a healthy diet while you're on the road, there are several smart choices that travel well and will keep you feeling good on your journey.
One thing to keep in mind is to keep yourself hydrated. Bottles of water are inexpensive and can be refilled easily when you stop for gas or rests. On the other side of the coin you'll probably be walking a thin line between drinking enough water and the need for extra stops! Just find what works best for you.
I'll usually pack one cooler and one bag for non-refrigerated snacks. It's also a good idea to throw in some napkins, wet wipes, plastic utensils, and a couple empty plastic shopping bags to use for trash.
Here are my very favorite healthy road foods:
There are so many great choices that my biggest challenge is not bringing too much food! Just keep in mind, that even if you're driving all day, you probably only need the same number of snacks as you normally would eat, as long as you're going to eat regular meals, too. Pack up and enjoy!