It’s not a male mindset, it’s an intellectually consistent mindset.
Science does not mean cherrypicking data and results and cramming in ideology when your personal beliefs are challenged. Why would the forces of natural selection and especially sexual selection suddenly stop at the boundary of sex? Rather than questioning your own views, you question established facts and insist it must instead be cultural. That is very unscientific.
Today, the majority of American women are overweight. A third are obese. Plenty of those women have sex, form relationships, get married, have kids, etc. Why are you trying to denigrate men who like healthy or underweight women and not those who like overweight women?
I could go on and lay out what the the seriously underweight female does signal to the male gaze
I know what you’re trying to snidely imply here. Since the dawn of civilization men have liked their women young, women have liked their men rich, and old hags have tried to shame both of them for it. Keep your unwanted sexual judgements to yourself, please.