I eat airport food. I don't eat McDonalds though, but other stuff. You'd be surprised, because you can find healthy stuff in the terminal. Often I'll go to "Chili's Too" and get a burger or salad to go. I'd rather spend $9 on a decent salad than $7 on McDonalds.
On the overnights, I really enjoy going to decent restaurants to get a good meal. In the $15 range I'd say. I'd rather eat good food on the road for a few bucks more, being able to sit down, relax, and eat... rather than pay $10 for some junk.
It usually ends up being:
Starbucks with fruit salad or muffin in the morning
Salad or sandwich in the afternoon
Decent meal in the evening
Some trips, like my next one, don't offer a chance to go get a decent meal on the road. We get in late, and are out early every day. Plus, I don't want to go eating a big meal before bed. So, I'm stuck with airport food. I just hate packing a big bag of food for the road. Tried it once, and although I enjoyed snacking, it was a pain in the ass. I do sometimes bring CLIF bars in my duffle I carry.
At all times, not only trips, I only drink water, cranberry juice, coffee, and beer! All within the allotted FAA and company rules, of course. I hate soda. I also try to drink milk more. Calcium is good for the bones.