Obesity, an increasingly prevalent and difficult-to-treat condition in the United States, affects more women than men. The distribution of body fat differs in the genders, with women carrying more fat "on" their frames and men more likely to exhibit central obesity, carrying weight "within" their frames. Changes in body distribution of fat occur with reproductive cycling and childbearing in women. Obesity in females can have important consequences for fertility, and menopause is accompanied by a significant increase in the waist-hip ratio in females, an important factor in raising their risk for coronary artery disease. Dieting and exercise have different consequences in the two genders: men, unlike women, maintain HDL levels and lose central obesity simply by dieting, while women require exercise in addition to restricted caloric intake to produce the same effects. Recent advances in elucidating the molecular pathobiology of obesity have not yet been examined with respect to gender. With very few exceptions, this is also true of studies examining the usefulness of anorexics in initiating and maintaining weight loss. More gender-specific information is required in these two last, newer areas of obesity-related investigation.