Orthorexia nervosa (ON) has gained increasing interest in the last 2 decades. Although a consensus on the diagnostic boundaries of ON has not yet been reached, there is some evidence for an overlap with eating disorders, obsessive-compulsive disorder, and psychotic disorder. Most of the knowledge about ON has emerged from studies of non-clinical and at-risk populations and is focused on differential diagnosis; therefore, further clinical studies are needed to better outline the ON phenomenon in a real-life setting.