Optimum body-mass index and maximum sexual attractiveness

Evolutionary psychology suggests that a woman’s sexual attractiveness is based on cues of reproductive potential. We compared two potential cues of body shape and weight. The conventional measure of female body shape is the waist/hip ratio, which has become a major determinant of physical attractiveness. A ratio of 0·7 (a curvaceous body) is said to be the optimum of attractiveness. The waist/hip ratio is thought to represent a fat distribution that leads to maximum fertility. However, anorexic women (who are amenorrhoeic and, therefore, infertile) can have the same waist/hip ratio as normal women, which suggests that this ratio is not a reliable measure of reproductive potential. We suggest that body-mass index is more closely related to fertility and health than waist/hip ratio, and, therefore, should be more important in determination of sexual attractiveness