Associations between orthorexia, disordered eating, and obsessive–compulsive symptoms: a systematic review and meta‐analysis

Objective: Orthorexia nervosa (ON) is defined as an unhealthy obsession with healthy eating, focusing on concerns regarding food quality and composition. Currently, there is still a lack of consensus about a clear definition of the construct. Specifically, it has yet to be clarified whether ON pertains to eating disorders (EDs) or obsessive–compulsive disorder (OCD) spectrum. Hence, we conducted a systematic review and meta-analysis addressing the magnitude of the association between these groups of symptoms. Method: PubMed, Medline, SCOPUS, PsychINFO, CINAHL, and Web of Science were searched from inception up to February 2021. Data from individual studies were pooled using a random-effects model. Pearson's r was used as the effect size metric. Subgroup analyses were conducted exploring the role of ON-related instruments, body mass index, study quality, and cultural context. Results: Thirty-six studies met the eligibility criteria and were included in the meta-analysis. Random-effects model yielded a moderate association between ON and EDs symptoms with an overall effect size of r = .36 (p < .001; 95% confidence interval [CI] = 0.30–0.43). On the other hand, the results showed a small association between ON and OCD symptoms with a mean effect size of r = .21 (p < .001; 95% CI = 0.15–0.27). Discussion: Meta-analytic findings showed that ON symptoms are more associated to EDs compared to OCD. Despite the similarities, the nonhigh magnitude of the pooled correlations suggests that ON might be different from pre-existing EDs and OCD. Hence, ON might be treated as a stand-alone ED and included as an emerging syndrome in the DSM classification.