Orthorexia nervosa is an excessive preoccupation with healthy eating that results in negative social consequences and severe psychological distress, particularly when elements of the diet deviate from someone's perception of “healthy”. Orthorexia nervosa may involve rigid dietary rules about how foods are bought, prepared, and consumed and strict avoidance of foods or ingredients that are perceived to be unhealthy, impure, or harmful. These self-imposed dietary rules may escalate over time. The ideas of “healthy” versus “unhealthy” eating habits in orthorexia nervosa are generally based on someone’s own perceptions rather than more objective definitions of healthy eating (such as published dietary guidelines). Despite this lack of objectivity, people with orthorexia nervosa may view their eating habits as superior to those of others.^[1][2]

Orthorexia nervosa is associated with health anxiety, obsessive-compulsive symptoms, low physical self-esteem, and perfectionism. First identified in 1997, orthorexia nervosa is not yet classified in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), and research is still in the process of determining whether orthorexia nervosa is a standalone disorder or a subtype of a pre-existing disorder such as anorexia nervosa or obsessive-compulsive disorder (OCD).^[2][3]

The signs and symptoms of orthorexia nervosa are obsessive thought patterns, beliefs, and behaviors surrounding food preparation and consumption — particularly a strong preoccupation with “healthy” or “pure” eating and self-imposed dietary rules — that cause psychological distress and negatively impact other areas of life. ^[1]

Dietary rules might include cutting out entire categories of foods for no reason beyond viewing them as “unhealthy” or “impure” (e.g., gluten, dairy, added sugars, carbohydrates, fats, preservatives, pesticides, oils, animal products). In orthorexia nervosa, beliefs about how foods and ingredients affect health are overvalued, meaning that the believed positive or negative impacts of a food on health are exaggerated. This can lead to extreme anxiety/distress and guilt when “unhealthy” foods are consumed or when “healthy” foods are unavailable.^[1][2]

The dietary restriction that occurs in orthorexia nervosa can lead to weight loss and nutritional deficiencies; however, the relationship between orthorexia nervosa and weight is not clearly understood. Some research suggests that, unlike the eating disorders anorexia nervosa or bulimia nervosa, orthorexia nervosa is not driven by negative body image and a desire for thinness. However, this idea has been challenged, particularly if someone views a smaller body as “healthier”.^[1][3][4]

Currently, orthorexia nervosa is not an established clinical diagnosis and is not listed in the DSM-5. If a clinician makes a diagnosis of orthorexia nervosa, it will likely be based on a thorough patient history and clinical judgment.

Several diagnostic questionnaires have been proposed, but most have major limitations and questionable validity. For example, some of the most widely used questionnaires in orthorexia nervosa research do not distinguish between orthorexia nervosa and “healthy orthorexia” (a general interest in healthy eating that is not harmful), which results in overestimated rates of orthorexia nervosa. Further research is needed to a) determine whether orthorexia nervosa is indeed a standalone diagnosis and b) create a diagnostic tool that can identify orthorexia nervosa with accuracy and specificity.^[1][5][2]

Currently, there are no medical treatments specifically for orthorexia nervosa because research is still in the stage of clearly defining the condition. However, given the overlap in symptoms with anorexia nervosa and obsessive-compulsive disorder, some clinicians may take similar treatment approaches. The goal of treatment is to increase the variety of foods eaten, including foods that were previously feared, address disordered thoughts around food, and restore nutritional and weight status if needed. This treatment process might involve individual or group cognitive behavioral therapy, family therapy, professional nutrition counseling, and medications (e.g., antidepressants, mood stabilizers).^[6]

To date, no supplements have been studied for orthorexia nervosa.

Currently, research is still focusing on defining orthorexia nervosa and developing accurate diagnostic tools. Accordingly, there is very little research exploring treatments for orthorexia nervosa at this time.

The causes of orthorexia nervosa are not known and are likely complex in nature. Predisposing factors might include genetics, a family or personal history of dieting or disordered/restrictive eating, personality traits (e.g., perfectionism, impulsivity, health anxiety, low self-esteem), mental disorders (e.g., OCD), problematic social media use, or a history of being bullied.^{[1][4][7][8][6]}

Ultimately, more research specific to orthorexia nervosa is needed to better understand its causes.