Citation: Novara, C.; Piasentin, S.; Mattioli, S.; Pardini, S.; Maggio, E. Perfectionism or Perfectionisms in Orthorexia Nervosa. Nutrients 2023, 15, 3289. https://doi.org/ 10.3390/nu15153289 Academic Editor: Paola Fadda Received: 4 July 2023 Revised: 20 July 2023 Accepted: 23 July 2023 Published: 25 July 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). nutrients Article Perfectionism or Perfectionisms in Orthorexia Nervosa Caterina Novara * , Sara Piasentin , Sofia Mattioli, Susanna Pardini and Eleonora Maggio Department of General Psychology, University of Padova, Via Venezia 8, 35131 Padova, Italy * Correspondence: caterina.novara@unipd.it Abstract: Purpose: Perfectionism is considered a transdiagnostic construct that characterises eating disorders (EDs) and obsessive–compulsive disorder (OCD) and that could also depict orthorexia nervosa (ON). The principal aim of this study was to investigate what dimensions of perfectionism mostly represent ON. Moreover, it was evaluated if dieting impacted the presence of orthorexic features and perfectionistic behaviour. Methods: The sample consisted of two groups—the “Diet” (n = 93), and the “No Diet” (n = 94) groups—composed of people with high and low orthorexic tendencies, respectively. Participants filled out self-report questionnaires to investigate orthorexic tendencies and different facets of perfectionism. Results: Analyses highlighted that people with high orthorexic tendencies showed higher perfectionistic features and that ON had a significant relationship with different facets of perfectionism. No interactions with diet were found. There- fore, no other differences were highlighted when the group type (Diet/No Diet) was considered. Conclusions: Regardless of diet, different facets of perfectionism characterise ON: perfectionism as a personality trait and perfectionism related to EDs and to obsessive–compulsive features. Our results evidenced that perfectionism could also be considered a useful construct in the conceptualization of orthorexia nervosa. Keywords: orthorexia nervosa; perfectionism; eating disorder; obsessive–compulsive disorder; transdiagnostic; dieting 1. Introduction Orthorexia nervosa (ON) is a psychopathological condition related to strict adherence to, and an excessive overconcern about, healthy diet. This disordered eating, described in 1997 by Steven Bratman, usually begins with a desire to improve well-being or to prevent/manage some clinical conditions [1]. The overconcerns about healthy food can lead to impairment in everyday functioning (e.g., social isolation, high levels of preoccupation with healthy eating, and a lot of time spent preparing food) and nutritional deficiencies [2,3]. To understand the core characteristics of ON, there have, over the years, been inves- tigations into the relationships with other psychopathological constructs, emphasising strong similarities between ON and eating disorders (EDs) [4–6], and features analogous with obsessive–compulsive disorder (OCD) [7,8]. However, recent studies have highlighted more similarities between ON and EDs than ON and OCD [9–11]. The comparable features between ON, EDs, and OCD mostly concern perfectionism [6,12–15], which has been iden- tified as a transdiagnostic feature in EDs [16] and in OCD [17,18]. Moreover, ON and EDs display disordered eating via strict control of food [16,19]. The literature highlights different types of perfectionism related to psychopathology as a general personality trait [20], a reflection of high and socially prescribed standards [21,22], and a belief that there is a perfect solution to every problem. This imposes the need to do things ideally, which can lead to severe consequences at the slightest mistake [23,24]. Frost et al. (1990) defined perfectionism as a multidimensional personality construct char- acterised by high personal standards of performance and tendencies for overly critical evaluations of one’s behaviour [20]. On the other hand, in the literature [25,26], two higher- order dimensions of perfectionism have been identified: perfectionistic strivings (PS), which Nutrients 2023, 15, 3289. https://doi.org/10.3390/nu15153289 https://www.mdpi.com/journal/nutrients