Eating disorders (EDs) are considered a major disease in the modern world, being one of the most prevailing public health problems among female adolescents and young adults in recent decades, and reaching epidemic proportions in many Western countries. The last two decades have envisioned an abundance of research in many aspects related to EDs. Nevertheless, EDs are still highly misunderstood disorders that often raise a host of negative emotions such as bewilderment, mistrust and fear. This book reviews research on the diagnosis and classification of EDs, as well as the historical and socio-cultural aspects and the genetics, biology and psychological considerations involved.