Orthorexia nervosa is a syndrome not yet recognised in major classifications such as the DM-5 or ICD-11. At first glance, it may not even appear problematic. Its core feature is the pursuit of ‘healthy’ eating. In the same way as exercise has many positive attributes and psychological effects, and indeed can be regarded as a form of an antidepressant, desiring a nutritious diet may be promoted as a means of improving mood and well-being. The Royal Australian and New College of Psychiatrists (RANZCP) in their most recent Clinical Practice Guideline (Malhi et al., 2021) for management of mood disorders indeed have a section recommending dietary practices to enhance other treatments for low mood. They state that ‘Diet with high proportions of vegetables, fruit, fish and grain but low animal fats appear helpful in depressive disorders’ (p. 38).