A study published in the American Journal of Human Biology found that individuals rated as above-average in physical attractiveness tended to have better health compared to those considered average-looking after a 10-year follow-up assessment. The research supports the notion that physical attractiveness may indicate good health, although the precise reasons for this relationship remain uncertain. ...
The original study is paywalled and there’s no indication on the number of subjects on the abstract.
But this part of the abstract screams confounding factors for me: