Evolutionarily speaking, it is logical to assume that physical attractiveness would correlate perfectly with health (the healthiest people would be considered the most attractive). That would maximise reproductive chances.

But studies show that men prefer women with lower BMIs, even when those BMIs are low enough that they are less healthy than the most healthy BMI group. This held true for people in Europe, Asia, and Africa, so it's unlikely that the preference is cultural.

>There was an inverse linear relationship between physical attractiveness and body fatness or BMI in all populations. Lower body fat was more attractive, down to at least BMI = 19.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4556148/

What explains this? Is there an error in the study methodology?