The beefier the man – measured by total fat-free mass, or arm and leg muscle mass – the more sexual partners he had, Lassek confirmed. The study also showed that more muscled men tended to lose their virginity at a younger age, compared to skinny men.

Yet in the same men, muscles didn’t come free. Muscle mass did a better job of predicting caloric intake than body mass index (BMI), age, or activity levels. A larger appetite may not seem like a cost in modern western societies, with a restaurant or grocer on every corner. But ancient humans struggled to get all the calories their bodies needed at times, Lassek says, which could have meant hunky men going hungry more often.