A policy such as this enacted by a *health care facility* is,it could be argued,a reasonable one.Ditto employees of schools and nursing homes.But not for most types of employers.However,it’s reasonable for *all* employers to charge employees who smoke more for health insurance,just as it’s reasonable for a life insurance company to charge a higher premium for those who skydive.
Reducing medical/insurance expenses is a legitimate goal of all firms.
Statistically men that smoke cigars and pipes live longer than men that don't smoke anything. That is because cigar and pipe smokers tend to have higher wealth. However a significant portion of the shorter lifespan of cigarette smokers is because of less wealth. Adjusted for this, tobacco use is nothing compared to the health problems caused by excessive carbohydrate use.