There is a saying out in the fitness world, I'm not sure who said it first, but it implores,

"Don't fuel your body where you fuel your car."

The implication is that gas station food is generally, well, lacking in the health department. I'm all for packing healthy snacks and meals but sometimes life throws you a curveball (or two) and you find yourself bereft of a delightfully nutritious snack and you have to make do with gas station fare. The goal should be not to fill yourself up, but to find something to tide you over until you can find a healthier option (like a restaurant or grocery store).Here are some tips:

Go for protein- When in doubt, aim for something with a decent amount of protein as those tend to be things like beef jerky. This isn't to say that you should spring for the hot dog that's been sitting in the warmer all day, but generally higher-protein snacks tend to be a bit better. Some fancy places, like Sheetz and Wa-Wa, actually have a made-to-order bar or fresh fare like hard-boiled eggs. Opting for a grilled chicken sandwich or even a hamburger (minus glops of sauce) will be friendlier to your waist-line than the chips and cookies.
Nuts and Seeds are Your Friends- Most gas stations have mixed nuts, sunflower seeds, trail mix or something like those. The fat will satiate you until you find a better option.
Be A Label Reader- Worst comes to worst and you're in the middle of nowhere and the only thing remotely "healthy" is the box of granola bars. Well, not so fast my friend. Read the label and you may find that the granola bar has more sugar than a Snickers bar. Actually, a Snicker's bar might even be better since it has the peanuts (fat and protein, to a degree) that will hold you over longer than a purely carbohydrate granola bar.
Drink Water- I know, drinking more water means stopping more, but at least you'll be hydrated and able to process any not-so-great food you have to eat more easily.

For the conscientious eater, it can be a bit tough to find edible fare in a gas station, but with a little discernment, it can be done!