Given that an important component of perceptual body dissatisfaction is the discrepancy between ideal and current body sizes, understanding how body size ideals are shaped and transmitted remains an important task for scholars. This review begins by examining cross-cultural patterns of body size ideals. Evidence is presented to indicate that the largest differences in body size ideals are no longer found between Western and non-Western cultures, but between sites differing in socioeconomic status. It is further argued that a thin ideal is now prevalent in most socioeconomically developed, urban sites. In explanation, it has been suggested that both Westernization and modernization bring cultural changes that promote a thin ideal. The present article reviews evidence in favor of both factors and concludes by looking at clinical implications for understanding corporeal experiences in a globalized world.