Yeah, I occasionally stop and get donuts or other breakfast food, and bring it in to work. My coworkers usually curse me, then devour it. A couple of other folks occasionally bring things in too, but not everyone... and we don't care.
If there were food themes, or if you were expected to bring something in... yeah that would get on my nerves very, very quickly. I'd be saving vacation time just so that I didn't have to attend. Not that I mind sharing food, I just detest being told that I'm going to.