Here and there my whole life I have read articles, and now media reports of studies, that try to tease out the effects of being "beautiful", exactly what is beauty, etc. My understanding of it all - yeah, humans are hard-wired to gravitate to the "good-looking", and in more serious studies that handsomeness always has a healthy/fit component to it.
I know, personally, if I were to board some mythical public transportation and one seat were available next to every person, no extras to be had so I could sit by myself, and many different types of human were already on, I would take the seat next to the fit and healthiest before I sat next to an obese person, not to mention someone unfortunately but obviously suffering from ill-health, or even mentally off-kilter (even if that off-kilter perception turns out to be that - just in my own perception). More filters: clean (as in hygiene) before dirty. Pleasant expression before scowling, growly-looking ones.
Whether we get to the point where healthy & fit becomes a whole class unto itself - I just do not know. I can see where you are thinking this way - as I grew up waaaaaay down the social ladder myself, even getting orthodontia done was a HUUUUGE deal and a boost to me personally (as poor folks can't get that done over here in the US, unless they are really clever and somehow find alternative pathways to make treatment happen anyway) and did change how I acted, both in public and in private.
I don't know why it is with me lately, but I spend a lot of time wishing the world had no classes at all - just a world where everyone had access to fine education, good healthcare, enough good food in the organic/biodynamic/Traditional/etc sense, and a clean environment. That fine education would include raising up kids able to preserve something like that for future gens. I am so tired of the usual "classes" and general run of things.
I have a mantra that I have spouted for years... "If I eat right, I feel right. If I feel right, I exercise right. If I exercise right, I think right. If I think right, I eat right..." Phil-SC