I live in the NYC area which is the king of having other people cook for you. Restaurants galore of all shapes ans sizes. It's all a matter of how much you want to spend and what kind of food you want. We also benefit from health food places. If I spend a lot ($30+), I eat out at a nice restaurant and get some grilled fish or something, maybe grilled veggie napoleon, etc. Cheaper would be gourmet sandwich and salad place. The gourmet places often use better fresh cut meats and not over salted deli cold-cuts and whole grain breads, etc. There are lots of whole foods style supermarkets here with premade foods which are pretty good quality and healthiness. For instance, I can go to a gourmet garage near my work and grab a piece of grilled chicken or salmon, golden beet salad, israeli cous cous, etc. Thats all about $10-15. I can also go to good health food bar and grab a hot veggie burger which for me (who loves beef) is very tasty, problem is I can easily down 2 since they are not filling.
Now without these more urban resources you have to really get resourceful and dig around your town/local area. Maybe a sandwich shop near you. Maybe a supermarket has a premade food deli of decent quality.
It's less about the place and more about knowing how it's prepared and what it's prepared with. Lettuce can be made more unhealthy then a cheeseburger by adding ton of fatty salty ranch dressing. You can also go to a fast food place and get some moderately ok food, problem with most fast food places is even if the fat content is low, sodium and sugar content is thru the roof. A lot of the fast food mentioned already is unhealthy or tastes like crap. I can't see why you can't have stuff that tastes good and is healthy too. It's easier in the cities but I'm sure you can find spots. Don't forget ethnic spots. Oftentimes ethnic places have some good, healthy food. Indian, chinese, mexican, carribean, etc. can all have some great wholesome foods for cheap. Eat what the locals eat, not what they sell to the gringos. For instance if you see the chinese workers in a chinese restaurant eat, usually what they eat is totally different from what they just sold you, and often much healthier.