Multidimensional perfectionism and orthorexia: a systematic review and meta-analysis.

Purpose: We provide the first systematic review and meta-analysis of research examining multidimensional perfectionism-perfectionistic strivings and perfectionistic concerns-and orthorexia.

Methods: The systematic review and meta-analysis was pre-registered and conducted using a search of PsycINFO, MEDLINE, Education Abstracts, and Oxford Academic, and ScienceDirect up to April 2023. PRISMA guidelines were also followed. Meta-analysis using random-effects models was used to derive independent and unique effects of perfectionism, as well as total unique effects (TUE), and relative weights. Moderation of effects were examined for age, gender, domain, perfectionism and orthorexia instruments, and methodological quality.

Results: Eighteen studies, including 19 samples (n = 7064), met the eligibility criteria with 12 of these studies (with 13 samples; n = 4984) providing sufficient information for meta-analysis. Meta-analysis revealed that perfectionistic strivings (r⁺  = 0.27, 95% CI [0.21, 0.32]) and perfectionistic concerns (r⁺  = 0.25, 95% CI [0.18, 0.31]) had positive relationships with orthorexia. After controlling for the relationship between perfectionism dimensions, only perfectionistic strivings predicted orthorexia which also contributed marginally more to an overall positive total unique effect of perfectionism (TUE = 0.35; 95% CI [0.28, 0.42]). There was tentative evidence that orthorexia instrument moderated the perfectionistic concerns-orthorexia relationship.

Discussion: Research has generally found that both dimensions of perfectionism are positively related to orthorexia. More high-quality research is needed to examine explanatory mechanisms while also gathering further evidence on differences in findings due to how orthorexia is measured, as well as other possible moderating factors.

Level of evidence: Level 1, systematic review and meta-analysis.