132505 20260217205510.0 doi 10.7189/jogh.14.03007 sideral 137663 ART-2024-137663 eng Barrada, Juan Ramón Universidad de Zaragoza (orcid)0000-0001-6887-6277 Orthorexia nervosa: research based on invalid measures is invalid 2024 Access copy available to the general public Unrestricted Orthorexia 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]. There are two explanations for this. Either humans have been unaware of this eating disorder pandemic or the results from that meta-analysis suffer from a systematic bias in measurement. We consider the second one more likely. Most importantly, the data that the meta-analysis is based on all came from studies that used the ORTO-15 questionnaire [3]. However, recent evidence shows this scale produces invalid scores for assessing ON [4]. Even the meta-analysis’s authors acknowledge the ORTO-15’s limitations in the discussion section. Given that ‘validity refers to the degree to which evidence and theory support the interpretations of test scores for proposed uses of tests’ (p. 11, [5]), no validity implies that the scores cannot be interpreted as intended. More clearly stated, the ORTO-15 does not measure ON and should not be interpreted as doing so. The logical conclusion is that any study using it (including meta-analyses) adds very limited knowledge to the scientific record or, even worse, it can be considered noise that some people will interpret as evidence. It has to be remembered that ‘validity is, therefore, the most fundamental consideration in developing tests and evaluating tests’ (p. 11, [5]). info:eu-repo/semantics/openAccess by-nc-nd https://creativecommons.org/licenses/by-nc-nd/4.0/deed.es 4.3 2024 PUBLIC, ENVIRONMENTAL & OCCUPATIONAL HEALTH 47 / 421 = 0.112 2024 Q1 T1 PUBLIC, ENVIRONMENTAL & OCCUPATIONAL HEALTH 47 / 421 = 0.112 2024 Q1 T1 1.172 2024 Public Health, Environmental and Occupational Health 2024 Q1 Health Policy 2024 Q1 5.7 2024 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Meule, Adrian 4009 735 Universidad de Zaragoza Dpto. Psicología y Sociología Área Psicolog.Evolut.Educac 14 (2024), 03007 [3 pp.] Journal of global health. Journal of Global Health 2047-2978 227501 http://zaguan.unizar.es/record/132505/files/texto_completo.pdf Versión publicada 2109898 http://zaguan.unizar.es/record/132505/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:132505 articulos driver 2026-02-17-20:25:00 ARTICLE