The comparison to food is a bit incongruous. Smoking, unlike eating, when performed as directed, is deadly. Eating is healthy and, in fact, vital, when performed as directed.
That doesn’t mean that over-eating is healthy or justifiable. But since, unlike food, even the first cigarette is unhealthy, smoking is, therefore, the clear “bad guy” of the two.
Also, flatulence aside, what you eat will have no effect on anyone else. What you smoke, however, will have an effect, and can even cause physical harm to someone else, aside for making them uncomfortable.
I don’t know what office those girls worked in, but I think the proper reaction is to ask him to stop, and, if he doesn’t, to avoid the steady second-hand smoke exposure by quitting on health grounds (and get unemployment, BTW, presumably, though I am simply guessing since I do not know the laws).
For all the guys who think they’ll stop when they date, once the fantasy wears off and/or any pressures kick in, the smoking will be extremely tempting, and I know of people who try (laughably unsuccessfully, of course) to hide their smoking from their wives, and others whose wives simply have to put up with it (with all the discomfort and dangers to themselves and their kids therein) because their addicted husbands won’t help themselves.
Hashem Yishmor.