I gave up smoking in 1994 after using acupuncture (that's another amazing story, it is also one of the reasons I put on so much weight).
Having done both, albeit at different periods in time, I can't possibly imagine smoking and fasting at the same time. I think either the fast or the fags would have to go. So I agree with what you say, but not sure how difficult it would be to give up smoking in favour of the fast.