I have eaten subway on tour, and it is probably one of the better choices, but it is still fast food crap for the most part. It's maybe OK for healthy young people to pound on this kind of abuse, but it isn't all that good idea if you have any serious reason to eat healthy. If you tossed the bun, and any of the meats, you would be pretty close, but then you might as well just buy a bag salad, etc...

I think there are several approaches to eating on tour. One is the "if I ride that much in a day, I can eat anything" school vs. "if I want to ride that far every day, better eat something sensible crowd". Both "work" for the people concerned, I guess.