A man's choice of partner is often a performance to gain social and sexual capital among other men. This is seen when men date only thin, conventionally attractive women publicly, despite porn data showing private attraction to larger women.

Historically, women who signaled vulnerability and need through sadness were more likely to receive assistance and resources. This evolutionary framework suggests a biological basis for women's globally reported lower happiness levels compared to men, as communicating need was a survival advantage.

Men's pursuit of extreme muscularity and masculinized features is often a failure of cross-sex mind reading. They are coding for formidability and respect from other men, whereas research suggests women often prefer a more neutral or even slightly feminized face combined with a masculinized body.

The impact of caloric restriction on testosterone is context-dependent. While it can improve testosterone levels in men with obesity or metabolic syndrome, the same dietary stress will likely decrease testosterone in young, healthy, lean men.

Dr. Marie-Pierre St-Onge's research reveals a sex-specific hormonal response to short sleep. Men experience a rise in ghrelin (hunger hormone), while women see a drop in the satiety peptide GLP-1, explaining different drivers for overeating when tired.

From an evolutionary perspective, a woman's body interprets a calorie deficit as famine, triggering fat storage and halting reproduction to survive. A man's body interprets the same deficit as a signal to hunt, leaning out and increasing cognitive focus to find food. This is a key sex-based metabolic difference.

Women's preference for less lean, slightly "softer" male physiques may be an evolutionary adaptation. This physique signals "formidability"—the ability to win a fight and protect—which is valued over the aesthetic of being extremely "shredded."

Men consistently overestimate the level of muscularity women find attractive. This can be viewed through an error management framework: from an evolutionary standpoint, the fitness cost of being perceived as insufficiently strong is far greater than the cost of being perceived as too muscular.

Research indicates women's ideal male body fat percentage is around 13-15%, which is lean but not "shredded." This contrasts with the bodybuilding ideal of sub-10% body fat, suggesting men's aesthetic goals are misaligned with female preferences.