Anorexia nervosa is a severe psychiatric disorder defined by persistent restriction of energy intake leading to significantly low body weight, an intense fear of gaining weight or becoming fat, and distorted perception of body weight or shape. As a research concept, it represents a critical area of study across clinical psychology, psychiatry, neuroscience, and public health, investigating its complex etiology involving genetic, neurobiological, psychological, and sociocultural factors, its severe medical complications and psychological comorbidities, and the development and evaluation of effective treatments and preventative strategies. Its significance in academic research is underscored by its high morbidity and mortality rates and its profound impact on individuals and healthcare systems.