Unfortunately getting into that argument is a minefield.

Just let them be adults and manager their life as they please. At one point they might becone fed up with life as a fat person and they'll make the effort.

And it they don't, well, there are people who smoke from teenage years all the way to the grave

But, either eay, people dont humiliate smokers the way they do with fat people

No, we just tax the shit out of tobacco, exclude them from certain insurance plans, blame and shame them about smoking indoors or inside vehicles, and tell smokers to go huddle outside and off to the side, away from doors, windows, and air intakes, while they do the thing we don't like.

Or were you thinking of air travel, where the difference between a smoker and a non-smoker is either negligible (because they aren't currently smoking), or completely excludes the smoker from the activity (because 16 hours in a plane is too long without a cigarette for them).

Humiliate them? Not often. But we sure as hell told them to take it someplace else; anyplace else, just not near the rest of us.