My wife and I fix up meals at home. Then we freeze them. I carry them in my refrig in the truck and heat them up either with microwave or with a 12v heater box.
I may treat myself to a "junk food" treat once a week. You can sure save a lot by preparing meals at home for the truck and eat one heck of a lot better than at a truck stop. It is sometime good to go in and get a breakfast or small meal and socialize with others, but I usually run on to the customer, camp there, eat a good meal in the truck, and start up the laptop for my entertainment.
I usually put the meals I fix up in heavy duty freezer bags or vacuum seal them with one of the vacuum units you can get at walmart. The vacuum bags are very heavy duty and will take the punishment of a microwave quite well.
Fresh fruits are a little more problematic. They tend to go bad quickly in a truck. I will usually get the canned "lite" fruits (low sugar) variety.
Also.. You might want to consider good supliments. I have been using collodial mineral suppliments for quite a few years. Some of the best I have used and at the best prices are from:
http://www.vivichealthproducts.com/
Easy to keep in the cooler and just take out once or twice a day and take a swig. Can't you tell how healthy I am from my picture? :lol: