The main aim of this study was to determine the prevalence of somatic and psychiatric comorbidities in female inpatients diagnosed with an eating disorder or obesity. Statutory health insurance data (11 - 25 years, N = 1269) was analysed. The most frequent comorbidities for both groups were affective, neurotic, stress-related and somatoform as well as personality disorders and diseases of the digestive system. Close to half of the patients diagnosed with an eating disorder suffered from psychiatric comorbidities. The majority of obese patients were diagnosed with somatic comorbidities.