For me the idea of health as the best and most real "high" in life was critical to my quiting smoking, drinking and over-eating bad food. The word health means whole, to heal means to make whole, (it also means holy which sounds about right to me even though I am an agnostic)

Even with that inspiration it was hard, I had to use cunning and trick the addiction with things like herbal cigarettes (with no nicotine) for many weeks.