The changing profile of eating disorders and related sociocultural factors in Japan between 1700 and 2020: A systematic scoping review

Objective The purpose of this study was to investigate the changing profile of the phenotypic expression of eating disorders (EDs) and related sociocultural factors in Japan between 1700 and 2020. Method The authors conducted a systematic scoping review in accordance with the PRISMA statement guidelines for scoping reviews. Results Findings indicate that Kampo doctors reported more than 50 patients with restrictive EDs in the 1700s, when Japan adopted a national isolation policy. On the other hand, only a few reports of EDs were found between 1868 and 1944, when rapid Westernization occurred. After World War II, providers began diagnosing patients with anorexia nervosa (AN) around 1960. Patients reported experiencing fat phobia, but did not engage in restriction for achieving slimness. However, after the 1970s, Japan experienced a rise in patients with AN who engaged in restriction to achieve thinness. Cases of patients who engaged in binge/purge symptomatology increased after the 1980s, followed by a steady increase in total ED cases after the 1990s. At various time points, providers attributed family conflicts, internalization of a thin ideal of beauty, changing food environments, and pressures associated with traditional gender roles to the onset and maintenance of EDs in Japan. Discussion Findings reveal that restrictive EDs were present as early as the 18th century; Japanese patients may present with both "typical" and "atypical" forms of AN; ED symptoms can persist in the absence of Western influence; and sociocultural factors, such as gender-specific stressors and family dynamics, may contribute to EDs for Japanese populations.