Puberty
Boys grow more slowly than girls but for a longer time. That is why most men are taller than women. By the end of puberty, adult males have heavier bones and more muscle than females. In an average adult man, muscle makes up 50% and fat 15% of his weight. On the other hand, 40% of an average adult woman's weight is made up of muscle while 27% is made up of fat. Because men have less body fat than women, their hips do not grow bigger. Some bones like those in the jaw and shoulders grow more in males than in females. That is why males have wider faces and shoulders but narrower hips.