The laying down of fat from food has important biological benefits. There may be enough fat even in a normally shaped adult's body to keep that person alive for several weeks without eating. The emaciated look that results from starvation indicates, apart from the wasting of muscle, how much energy is stored in fat under the
skin. The adult female human body typically contains a higher proportion of fat than does that of the male. This presumably promoted survival of the genes carried by the foetus when the pregnant woman and her familv or tribe ran out of food.