Overall proportion of orthorexia nervosa symptoms: A systematic review and meta-analysis including 30 476 individuals from 18 countries

Abstract

Background To date, no previous meta-analysis has determined the overall proportion of orthorexia nervosa symptoms on a global scale. The aim of the present study was 2-fold: first, to establish the overall proportion of orthorexia nervosa symptoms on a global scale, assessed with the ORTO-15 questionnaire; and second, to determine the role of sex, type of population, mean age, body mass index, and the temporal trend in relation to orthorexia nervosa symptoms. Methods Four databases were searched (PubMed, Scopus, Web of Science, and Cochrane Database of Systematic Reviews) with date limits from January 2005 to June 2023. Studies assessing the proportion of orthorexia nervosa assessed using the ORTO-15 questionnaire with a cutoff of <35 or <40 points were included in this review. Results The overall proportion of orthorexia nervosa symptoms (using the cutoff <35 points) was 27.5% (95% confidence interval (CI) = 23.5-31.6, I 2 = 97.0%). In addition, no significant differences were observed between females (34.6%, 95% CI = 29.5-39.8, I 2 = 96.1%) and males (32.1%, 95% CI = 26.5-38.1, I 2 = 93.1%). According to the type of population, the highest overall proportion was found in people focused on sports performance or body composition (34.5%, 95% CI = 23.1-47.0, I 2 = 98.0%). Notwithstanding, caution should be exercised in interpreting this result, as reverse causality could be a potential pitfall in this relationship. Conclusions We found that approximately three out of 10 study participants showed orthorexia nervosa symptoms according to the ORTO-15 tool. This overall proportion was higher in those participants who were athletes or fitness practitioners. Over the years, the proportion of orthorexia nervosa symptoms seems to be increasing. These high percentages and their increase are worrisome from a public health perspective and highlight the need to develop psychometric instruments to aid in clinical diagnosis and treatment efficacy. Registration PROSPERO (CRD42022350873).

Orthorexia nervosa: Research based on invalid measures is invalid

“…The current stage of research and knowledge about ON leaves more doubts than certainties. Among the certainties are: a) it is still very uncertain whether the prevalence of ON is almost 'three out of ten' [1], b) biased assessment tools cannot help us to advance, c) ON research has contributed to pathologising healthy approaches to eating, and d) this area of research needs better psychometric and theoretical approaches for trying to understand this relevant phenomenon. The meta-analysis [1] clearly illustrates that psychometric quality plays a largely neglected role in the ON field.…”

“…Among the certainties are: a) it is still very uncertain whether the prevalence of ON is almost 'three out of ten' [1], b) biased assessment tools cannot help us to advance, c) ON research has contributed to pathologising healthy approaches to eating, and d) this area of research needs better psychometric and theoretical approaches for trying to understand this relevant phenomenon. The meta-analysis [1] clearly illustrates that psychometric quality plays a largely neglected role in the ON field. Considering that the problems with the ORTO-15 have been articulated for several years, it is surprising that so much research that uses it is still being published.…”

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O rthorexia nervosa (ON) refers to a strong preoccupation with a healthy diet with negative emotional, cognitive, or social consequences when trying to approach this goal and when the eating behaviour deviates from these self-imposed rules. According to a recent meta-analysis published in this journal, the prevalence of ON could be as high as 27.5% [1]. If that was true, ON -which is not (yet) a recognised eating disorder in diagnostic classification systems -would be the most prevalent of all eating disorders and, in fact, of all mental disorders [2].

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Orthorectic behavior among students and motivation for physical activity, dietary habits, and restrictive eating

“…Learning about the motivators for physical activity in groups at potential risk for non-specific eating disorders seems reasonable, as they can provide an early diagnostic signal ( 51 , 52 ). In the study provided by López-Gil et al ( 53 ), data concerning the prevalence of orthorexia nervosa symptoms across 18 countries were presented, involving a total sample of over 30,000 participants. This meta-analysis reveals that the overall proportion of orthorexia nervosa symptoms stands at 27.5%, with marginal differences observed between genders.…”