An office that is worried about the productivity loss of smoke breaks is run by idiots.
It's also relevant to more than just productivity, e.g. a receptionist leaving the phones unattended.
Here for example : http://well.blogs.nytimes.com/2014/04/30/want-to-be-more-cre... but there are likely more serious link around.
The reality is that most people don't do more by skipping their breaks. They just start working more slowly or their minds drift away. This is more true for people doing creative jobs which is more and more people every year.
I'm software developer solving relatively difficult problems, I can really focus maybe 2-3 hours every day on real work. I spend the rest trying to do mundane stuff, learn things, talk to people, etc.