We've just started to go camping in the last year with our son (now 5). It's something that my husband did a lot of growing up. Me, not so much. Unless you count borrowing a tent and pitching it in the back yard, or driving to Presque Isle state park for a couple of nights.
The advantage to camping is that it can definitely save you money. Campsites for tent campers can be anywhere from free to $40 a night (in my limited experience). A lot cheaper than most hotels. Now of course, amenities vary (some have no running water anywhere).
About half the time that we've gone camping, it's been at Joshua Tree with our GREAT neighbors, who have a camping van. Having access to a fridge helps with the food issue, and allows you to have a more "normal" diet while camping. If you are limited to a cooler, then eating good food while camping is something that takes practice, and knowledge of where you are staying. Case in point: on our last Joshua Tree trip, I made oatmeal. It was not very successful. The people at the campsite next door made blueberry muffin bread on an open fire in a dutch oven. Which...seems a lot more advanced than my camping abilities.
We did take a cooler, which is about 20 years old. Let me tell ya, it's starting to smell a little funky. For our upcoming camping trip (Grand Canyon!) we bought a new cooler. Turns out it's rated to keep the ice frozen for 3 days in 90 degree weather. I guess there have been quite a few engineering advances in the last 20 years or so when it comes to cooler technology.
It is very possible to make delicious and healthy food while camping. With a cooler and a grocery store, you can have fresh fruits and vegetables, meats, rice - a wide variety of healthy foods. Of course, all of this takes prep and the ability to wash dishes - the ability to do this while tent camping will vary on where you are staying. Some places have running water, some have "dish washing stations", others have nothing.
As a newbie camper, I've decided that on this next trip, we will be forsaking some of the "healthy" for the "simple". I suppose as time goes on, I will get better at this. I am aiming for things that can be eaten raw, heated on a fire, or cooked with just water.
Here's a picture of a few of the things that I am taking on this trip. Yeah, I know, the noodles have MSG. I lecture coworkers on the evils of MSG. But we're camping. And we don't do that very often. And they were only $0.33 each. Lunches will be PB&J sandwiches (still need to buy bread). Breakfast...nuts, granola bars, maybe some muffins. Maybe I should bake some blueberry muffins before we go. We are only camping for 2-3 days and staying in hotels for the other nights on this trip. The advantage to the "just add water" meals, though, is that you can make them using the coffee pot in a hotel room. Or using your hot pot. Any way to save money on a vacation can only help. Gas prices being what they are, I expect the gas alone to cost about $350 on this trip.
As far as fresh foods go, we've got carrots and apples - both are very tasty and they travel incredibly well. I may take some oranges also.