I don't think I'm going to allow people to take smoke breaks at work.
Do you think it's fair to stop people from having a smoke at work?
I don't care about their need to smoke. They should live healthy.
I get that you don't want people to smoke because it is bad for them but you can't control your employees like that. It's not an illegal drug and they can also still end up smoking during their lunch break or are you going to stop them from having lunch too?  Let people make their own decisions or people will likely stop working for you.
This job isn't for everyone.
You're always going to have employees with habits that you don't approve of, but as long as they don't get in the way of their job then you shouldn't get hung up on them. Employees are their own people with their own lives, and if you try to stifle them then they aren't going to want to work for you.