Interesting that the outward man so often belies something of the inward.
A bright disposition will be relfected in the countenance. Likewise with acidic.
A sharp mind can illuminate a person as well. Each of these things can make someone visibily more "attractive" and they are also substantive character traits worthy of praise.
Similarly, many people do not want to ponder the fact that who you are and how you think affect (or should) how you live, which in turn affects how you look.
If its not important to you, then don't b!tch about it.
If it IS important to you, then get up and do something about it.
"Why do you watch what you eat? You're not fat!"
...well, duh.
"Why do you work out? You're already in good shape!"
...well, duh.
<shrug>
I do these things for my benefit.
Period.
There are some things you can discern about a person by their appearance...but of course they are limited to mostly just that: matters of appearance.
If you are out of shape, I can discern that you either don't or didn't work out. No harm there, but you can't infer anything else from it with any accuracy.
If you are dirty, your hair is greasy , and your clothes are rumpled and stained then I can discern that you have not bathed recently and that you have been in your clothes for a while. If I see you routinely in this state, I may begin making more general observations.
oh and, if you are going to define "shallow" as "someone who makes value judgements about another based on their physcial appearance and atractiveness" be careful that you don't become equally "shallow" in your application of it.