Eating disorders are a group of heterogeneous mental disorders characterised by a distorted relationship to food and eating that often leads to abnormalities in body weight, including both extremes of the weight spectrum. In this section we focus on three disorders: anorexia nervosa, bulimia nervosa and binge eating disorder. Both anorexia nervosa and bulimia nervosa often have an early onset in adolescence or young adulthood and are much more common in females than in males, whereas binge eating disorder is nearly similarly prevalent in men and women (around 5%) and can start later in life [1]. Anorexia nervosa has the highest mortality rate (up to 20%) of any psychiatric disease and a prevalence around 1% in women [1]. Bulimia nervosa has a higher prevalence in women, around 2%, and occurs often undetected for longer periods [1]. Despite the huge impact that eating disorders can have on individuals and families, data on prevalence, frequency of specific symptoms and comorbidities are only sporadically available. The pathophysiology of these diseases is still only partially understood. There is still no specific pharmacological treatment available, which can be partially explained by the multifactorial origin of the diseases and the still insufficiently understood pathophysiology.