Food is variable in quantity and quality, but generally ok.
I suggest that you get in line early to ensure that you get food. I have seen the food vendor run out, then scramble to substitue something relatively crummy for whatever they were serving at first. They never seem to understand that we cyclists eat like locusts.
If you are staying in camp, I suggest taking breakfasts because they are convenient, available before you start to ride, and it's hard to screw up breakfast.
Suppers, elect the meals that appeal to you from the menu sent with your rider pack, but also plan to eat in local restaurants. This year's towns are large enough to offer variety close by, and CNC organizes shuttles around town. You need to get a broad feel for what it's like to do one of these rides, and town in the evening is part of that.
Oh, CNC camps sometimes are on facilities that cannot serve or permit alcohol on the premises, so a cold one at a local bar with your cycling pals is extra special. However, don't be surprised to find small groups discretely enjoying adult beverages in tent city. It's usually live and let live.
If you have special diet needs or are picky about your food, you might wanna try eating in towns. It's hard to cater to a few when vendors are serving the masses for just one night. Nevertheless, the food is often surprisingly good.
My favorite story re food occurred in 2001. One of the vendors had made homemade bananna pudding, and let us serve ourself from the long stainless tray as we wnet thru the line. The first twenty diners took all of the pudding, and when the caterer heard the 20th scraping the tray, turned around and said "My God, that's all the pudding we have, it's supposed to feed all 500." Yeah, right! If you see the caterer letting cyclists serve themselves, immediately look or ask how much food he brought.
They generally have PB&J sandwiches at the 2nd or 3rd rest stop of the day every day. How much you enjoy this may depend upon how much you love (or not!) PB&J! :)
Having purchased all the meals on my first CNC and half the meals on the second CNC, I must say that I really enjoyed eating out with new and old friends rather than taking a chance on the quality and quantity of camp food. I'm not one who likes a big, heavy breakfast before a day or riding so I used Harold's Coffee Detail (an optional private service) for good coffee and muffins/danishes most mornings. I don't know if Harold will be at CNC this year - his web site seems to have disappeared. For lunch plan on the infamous PB&J (which is actually good and very welcome during a long ride) or perhaps a restaurant in some interesting small town.