foot, which is simply to say, fresh is sexier than preserved. Or, as one saucy woman put it on the www.eatveg.com, "I find my husband more sexually appealing knowing that he is not a vessel full of decaying carcasses."
Of course, I speak mainly of psychological considerations, but there are physical aspects as well. I'm no doctor, but from my experience, vegans usually seem fitter than meat eaters, and if you're into that sort of thing, they're often thinner too. Then there's this important consideration. Male vegans are far less likely to suffer from impotence than their meat-eating counterparts. Animal products clog blood vessels, and apparently these are needed to maintain good erections.
In conclusion, I doubt that a vegan diet actually makes hair, skin, teeth, or any other body part look, feel, or taste much different. But then again, I have heard stories. If you're curious, I suggest locating a vegan and finding out for yourself.