From a nomadic to an agricultural society, from the Renaissance woman to the supermodel, woman has waxed and waned to coincide with the fluctuations of societal standards. With a dramatic increase in eating disorders diagnosed in the 1980s, researchers and clinicians began seeking a reason for such an increase as well as a treatment plan. This book reviews the evolutionary perspective, cultural influence, and cognitive aspect of eating disorders. Using expectancy theory, as applied to body image, the author has completed a study of expectations of thinness. Using two separate scales to identify expectations and attitudes of thinness, manipulations of media images, and body composition measurements, results indicate a trend away from the thin ideal. While women are still internalizing the thin ideal, the expectations of thinness are conflicting. The analysis should shed some light on the expectations that women hold of those who are thin, and should be especially useful to those professionals who seek a greater understanding of eating disorders and body image.