I see plenty of beautiful people walking around too. However, I've also lived in a few places and I know that it's quite deceptive. Attractive people tend to go out more and live in denser areas. A lot of people have normal but average to ugly faces too, even if properly developed. I'd say at least half the moms in my kids daycare I don't consider attractive, even if not overweight.
But in general, yes being healthy equates to looking good. It really just comes down to good nutrition, especially in the womb, followed by good nutrition growing up, good sleep, and good breathing. I've been toying with the idea of having a book made on the topic. Something along the lines of "Princess eat, sleep, and breathe". What do you think? I'm not a kids expert, hard to communicate these topics appropriately to kids AND convince parents it's good to read to them.