I'm not sure I see the connection between vanity sizing and health. I don't think men think to themselves "34 inches is healthy" -- they pretty much only care

I'm not sure I see the connection between vanity sizing and health. I don't think men think to themselves "34 inches is healthy" -- they pretty much only care how they measure in comparison to other men. You can call it 34 or 40, it doesn't impact the question of "am I fatter than my competition?" Put another way, I don't think men would be likely to go on diets if you immediately renumbered pants sizes, as long as they were still in the same place relative to other men.