Most the guys in my fraternity were in very good shape, most of us were high school athletes and continued to play intramurals in college and went to the gym almost every day. A few guys had dad bods but no one was really overweight, let alone obese, plus the best part of a fraternity is everyone is working together to better ourselves so even if someone was letting themselves go there would be enough people heckling them to get back in shape, or dragging them to the gym in the morning. Almost everyone had a lot of sex, even the guys with dad bodies but I think that just had to do with social status and environment, not fitness. Sexual status is rarely based on looks alone, but if you remove things like status and wealth from the equation fit people win every time.