Why is not hiring for weight any different than not hiring for smoking? Each is equally difficult to remedy. You could argue that both might be the result of an addiction or "out of the control" of the person. Both cause more sick days and increased medical costs. For women, it is almost harder to stop smoking than to lose weight.
Why should the other nurses take up the slack for an obese nurse or, on the other hand, one who has to take smoke breaks every hour? For every obese nurse that swears she is just as healthy as a skinny one, one smoker could swear the same thing. My daughter is a family practice MD. A very obese patient (one of the hospital nurses) was complaining in her office (as her patient) that the said nurse could not make it across the hospital parking lot without stopping for breath. My daughter looked up and innocently asked if she could assist her in losing weight. The nurse acted like her doc was nuts. All she wanted was a disabled parking sticker. Well, if the nurse can't make it across the parking lot, how is she handling her patients?