To evaluate the feasibility of recruiting women of different socioeconomic status and minority groups and to determine whether these women could achieve and maintain a modified fat-eating pattern. The full-scale trial sought to determine whether a low-fat diet could decrease the incidence of cancer and coronary heart disease in postmenopausal women. The National Heart, Lung, and Blood Institute contributed funds over a three-year period to measure lipids, lipoproteins, and other cardiovascular disease risk factors.