Orthorexia nervosa is a term coined by Bratman. Bratman created the term 'orthorexia', meaning 'proper nutrition', by combining the Greek words 'ortho', meaning correct, proper, and 'oreksis', meaning hunger [1]. Defined as an obsession with healthy eating, orthorexia nervosa begins with a desire to consume healthy food. Over time, this desire turns into an obsession with consuming healthy foods and becomes the pathology of an eating disorder [2]. Although there is no agreed definition and diagnostic criteria for orthorexia nervosa [3], people with this pathology attach excessive importance to eating behaviour [4] and focus on the quality and purity of food [2]. This focus leads to various physical, psychological and social problems. Physically, there are problems caused by malnutrition and weight loss (osteopenia, anaemia, pancytopenia, metabolic acidosis), various stomach problems and even heart failure. Psychologically, excessive preoccupation with healthy eating can interfere with everyday functioning. Feelings of guilt and self-disgust can occur when a person violates healthy eating behaviours. Socially, individuals begin to lead increasingly isolated lives because they prefer to eat alone and are intolerant of those who are different from them, which negatively affects their close relationships [5, 6].

Although orthorexia nervosa is not yet included in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders 5 (DSM-5), several researchers have published diagnostic criteria for orthorexia nervosa in their studies. The diagnostic criteria used by Morezo et al. Anxious and obsessive preoccupation with the quality and purity of food; negative effects on physical health as a result of inadequate and unbalanced diet; impaired functioning in academic, social and occupational areas due to obsessive thoughts, beliefs and behaviours about healthy and pure nutrition; This disorder should not be caused by another disorder such as obsessive–compulsive disorder, schizophrenia or any other psychotic disorder; this disorder should not be caused by religious beliefs, should not be applied due to any food allergy and should not be caused by any medical reason [7]. Dunn and Bratman (2016) published new diagnostic criteria to better conceptualise the obsession with healthy eating, arguing that the diagnostic criteria published by Morezo et al. (2012) do not address weight loss in orthorexia nervosa [8]. The diagnostic criteria proposed by Dunn and Bratman are as follows Excessive mental preoccupation with healthy eating caused by a diet or set of beliefs; exaggerated emotional distress related to the selection of foods considered unhealthy; weight loss due to the choices made (the primary goal is not weight loss); medical complications resulting from malnutrition and severe weight loss; impairment in occupational, academic and social functioning due to beliefs, attitudes and behaviours related to healthy eating; and assessment of self-esteem, self-worth and positive body image within the context of adherence to healthy eating behaviours [8]. When the reports of researchers who published both diagnostic criteria are evaluated together, the unofficial/temporary main diagnostic criteria for orthorexia nervosa can be listed as: excessive obsessive thoughts and preoccupation with healthy eating, strict dietary rules, and excessive anxiety and emotional distress due to breaking the rules [9].

When reviewing the literature, it is controversial whether orthorexia nervosa is a lifestyle or a clinical disorder [10]. If orthorexia nervosa is a psychiatric disorder, another issue that remains unclear in the literature is whether orthorexia nervosa should be considered a separate disorder or a subset of eating disorders or obsessive–compulsive disorder [3, 5, 11]. Pontillo et al. (2022) analysed the studies on the clinical importance and classification of orthorexia nervosa between 2015 and 2022. According to the results of this systematic review study, it was observed that people with orthorexia nervosa generally had a lower level of functioning, as well as lower life satisfaction, lower well-being and more depressive symptoms. Accordingly, it is stated that orthorexia nervosa is not a lifestyle, but an important clinical condition [12].

In this clinical picture, one of the pathologies associated with orthorexia nervosa is the eating attitude [5]. In the study conducted by Dunn and colleagues, the Eating Attitude Test Short Form (EAT-26) scale is successful in detecting eating disorders and orthorexia nervosa, but it cannot express which eating disorder the individual suffers from [13]. Another study accepted that orthorexia nervosa has subclinical features of eating disorders, but it was not determined whether it should be a separate disorder or within eating disorders based on the research findings, and more research was needed on this topic [14]. Barthels et al. reported in their study on the similarities between orthorexia nervosa and anorexia nervosa that orthorexia nervosa may be a milder symptomatic form of anorexia nervosa [15]. In a study investigating the relationship between obsessive–compulsive symptoms and eating attitudes in individuals who regularly exercise and those who do not, it was found that as the predisposition to orthorexia nervosa increased in individuals who regularly exercise, the deterioration of eating attitudes also increased, and in this direction it was concluded that orthorexia nervosa is closer to eating disorders than obsessive–compulsive disorders in classification [16]. In the study conducted by Lucka et al. to determine the frequency of orthorexia nervosa in adolescents and young adults and to investigate whether orthorexia nervosa is a separate disorder or an eating disorder, it was reported that orthorexia nervosa is not a disorder in itself and meets the diagnostic criteria for eating disorders [17]. Taken together, the results of the above studies suggest that orthorexia nervosa is shaped by the dynamics of eating attitudes, and that orthorexia nervosa may be related to disordered eating attitudes.

One of the factors thought to be responsible for the clinic of orthorexia nervosa is difficulty in emotion regulation. Awad and colleagues reported in their study (2021) that individuals with orthorexia nervosa disorder have difficulty identifying, describing and regulating emotions, and that as an individual's predisposition to orthorexia nervosa increases, so do their difficulties with emotion regulation [18]. Another study was conducted by Vuillier, Robertson & Greville-Harris (2020) to fill the gaps in the literature on orthorexia nervosa and to understand whether it should be included in the classification of eating disorders. This study reported that high scores on emotion regulation difficulties and low scores on orthorexia nervosa were statistically related, and that individuals with a high predisposition to orthorexia nervosa had more difficulty identifying and accepting their emotions, resisting impulses, engaging in goal-directed behaviours, and finding the right strategies when unhappy compared to individuals with a low predisposition to orthorexia nervosa. The authors state that orthorexia nervosa may emerge as a coping strategy for individuals with emotion regulation difficulties [19].

Another variable that has been implicated in the clinical picture of orthorexia nervosa is self-esteem. There are conflicting results in the literature regarding the relationship between vulnerability to orthorexia nervosa and self-esteem. Brytek-Matera et al. (2022) conducted a study involving 554 individuals to assess the relationship between self-esteem, physical activity levels and disordered eating attitudes in Italian and Polish young adults with orthorexia nervosa. According to the results of this study, there is a positive correlation between orthorexia nervosa and high self-esteem. Accordingly, it was emphasised that individuals who make and maintain their own choices within the framework of healthy eating behaviour also have high self-esteem [20]. Another study conducted with female undergraduate and graduate students examined the relationship between self-esteem, emotion regulation difficulties and psychological resilience and orthorexia nervosa. According to the results of this study, no significant relationship was found between self-esteem scores and predisposition to orthorexia nervosa [21]. Similarly, Oberle et al. (2017) examined the relationship between orthorexia nervosa and self-esteem in a study of 459 university students and found no relationship between self-esteem and orthorexia nervosa symptoms [22].

There are also studies in the literature that examine the relationship between orthorexia nervosa and depression. In a study conducted by Awad et al. (2021), it was found that there was a positive relationship between depression and predisposition to orthorexia nervosa, regardless of gender. Following this finding, it was highlighted that as an individual's level of depression increases, the likelihood of developing an obsession with healthy eating increases at the same rate [18]. The researchers noted that the predisposition to orthorexia nervosa may have led to individualisation, resulting in increased isolation and depressed mood. Another study reported that interest in healthy eating differs from orthorexia nervosa in terms of its relationship with mental health, and that orthorexia nervosa classified as a disease is more associated with depressive symptoms than healthy orthorexia nervosa [23]. In addition to depression, there are studies showing that anxiety disorders are also important in the clinic for orthorexia nervosa. However, information on this topic in the literature is mostly limited to studies that treat orthorexia nervosa as an eating disorder. Studies specifically investigating the relationship between orthorexia nervosa and anxiety are limited. This is a gap in the literature. Yılmaz and Dündar (2022) investigated the effect of anxiety and self-esteem on the susceptibility to orthorexia nervosa in a group of 248 participants in a highly educated group. They found that individuals with high anxiety scores were more prone to orthorexia nervosa than those with low anxiety scores [10]. According to the results of a study on the level of orthorexia nervosa in students studying medicine at different universities in Lebanon, as well as the relationship between orthorexia nervosa and eating attitudes and anxiety, orthorexia nervosa was found to be associated with impaired eating attitudes, while no relationship was found between anxiety scores and orthorexia nervosa scores [24]. Valente et al. (2020) conducted a study with individuals over the age of 16 who self-diagnosed themselves with orthorexia nervosa in their Instagram posts, as the obsession with healthy eating has not yet been classified as a disease and there are no official diagnostic criteria. In this study, 185 people were first asked to complete a questionnaire and then 10 randomly selected people were given a semi-structured interview. According to the results of the study, participants cited biological, psychological and interpersonal changes in their lives as the reason for having orthorexia nervosa. Participants who indicated that these changes in their lives caused them to feel anxious and that they developed orthorexia nervosa to control this anxiety indicated that they viewed orthorexia nervosa as a strategy to cope with anxiety [25].

When the above literature information is evaluated holistically, it can be seen that eating attitudes, anxiety, depression, emotion dysregulation and self-esteem are related to orthorexia nervosa and studies have addressed one or more of these variables together, but there is no study that addresses all variables together. This study was conducted to address this deficiency in the field and to examine the predictive power of eating attitudes, anxiety, depression, emotion regulation difficulties, and self-esteem variables in women's susceptibility to orthorexia nervosa. At the same time, the contribution of some demographic data (natural food consumption, self-perception, weight perception, eating and exercise habits, etc.) to women's susceptibility to orthorexia nervosa should be investigated.

To this end, the research questions are listed below:

The study used the relational screening model. The relational survey model is a survey approach that aims to determine the existence of covariance between two or more variables. The relational survey model attempts to determine whether or not the variables change together, and if there is a change, how it happens [26].

Female participants between the ages of 19 and 45 were included in the study. The lower end of the age range was set to exclude the confounding effect of adolescence, and the upper end of the age range was set to exclude the confounding effect of menopause. Participants were recruited using snowball sampling. Snowball sampling is a sampling method generally used when individuals with certain characteristics are rare or difficult to reach in society [27]. As orthorexia nervosa is also considered a lifestyle, this method was chosen to reach the participants through their acquaintances. The sample size was determined by considering the number of participants required for different population sizes (N = 384) [28]. In this study, 398 participants were reached, and since the participants with extreme data sets were excluded from the sample, the research results were reached by using the data of 380 participants.

To collect data, a form was created by combining the researcher-developed Sociodemographic Information Form, Orthorexia Nervosa Rating Scale Short Form (ORTO-11), Eating Attitudes Short Form (EAT-26), Difficulties in Emotion Regulation Scale (DERS-36), Rosenberg Self-Esteem Scale (RSES), Beck Depression Inventory (BDI) and Beck Anxiety Inventory (BAI).

The demographic information form was prepared after a literature review [3, 5, 8, 10, 13, 18, 19] and the conditions (weight (BMI was calculated and divided into 3 groups as normal, BMI was calculated and divided into 3 groups as normal, above normal and below normal) that are considered to be related to orthorexia nervosa, perception of health, dieting status, regular exercise status, self-body perception, weight perception, attention to natural food consumption, attention to diet, behaviour change when receiving information about nutrition). Inclusion criteria were female gender and experience of healthy food consumption as a lifestyle. Exclusion criteria were male gender, presence of chronic physical and psychiatric diseases, regular use of medication, smoking, alcohol and drug use.

ORTO-11 is the short form of the ORTO-15 scale and was developed to assess the orthorexia nervosa predisposition of the women participating in the study. ORTO-15 was created by Donini and colleagues by removing some questions and adding some problems from the ten-question Orthorexia Test created by Bratman to understand orthorexia nervosa tendencies [29]. The scale, whose Turkish validity and reliability study was conducted, consists of 11 items. The eighth item is reverse scored. On the 4-point Likert-type scale, one point reflects the predisposition to orthorexia nervosa, while four points reflect the predisposition to non-orthorexia nervosa. Low scores on the scale indicate an increased predisposition to orthorexia nervosa [30]. In this study, the Cronbach alpha value was calculated to be 0.59.

The Eating Attitude Test Short Form (EAT-26), which is the short form of the original form of the Eating Attitude Test (EAT-40) developed by Garner and Garfinkel to assess attitudes to risky eating, has been revised by Gardner and colleagues and consists of sections A, B and C. In section B, the scale items are listed and scored as a 6-point Likert-type rating. Only the 26th item is reversed. Sections A and C are additional questions asked to facilitate diagnosis, the answers in this section are not included in the scoring. Scores of 20 and above on the EAT-26 indicate risky eating behaviour [31]. As a result of the Turkish validity and reliability study of the scale, Cronbach's alpha value was reported to be 0.83 [32]. In this study, the total internal consistency coefficient of the scale was found to be 0.72.

The DERS-36, developed by Gratz and Roemer, is a 5-point Likert scale [33]. There are reverse-coded items in the scale. These are items 1,2,6,7,8,10,17,20,22,24 and 34. As the scores obtained from the scale increase, it is assumed that the difficulty in emotion regulation increases. The DERS-36 has six sub-dimensions. These sub-dimensions are listed as ''awareness'' (expressing that there is no awareness of emotional reactions), ''openness'' (expressing that emotional reactions are not understood), ''non-acceptance'' (expressing that emotional reactions are not accepted), ''strategies'' (expressing that effective/functional emotion regulation skills cannot be used), ''impulse'' (expressing that there are problems with impulse control during emotion regulation), ''goals'' (inability to perform goal-directed behaviours while regulating emotions). The Cronbach's alpha value of the Turkish form was found to be 0.94, and the coefficients of the sub-dimensions were reported to vary between 0.90 and 0.75 [34]. In this study, Cronbach's alpha was found to be 0.94.

The RSES is a self-report scale with 12 sub-dimensions and 63 items. The sub-dimensions of the scale can be used separately. In this study, the 10-item self-esteem sub-dimension of the scale was used. Five questions in the self-esteem subscale are reverse coded. The scores that can be obtained from the scale range from 0 to 6. 0–2 points indicate high self-esteem, 2–4 points indicate medium self-esteem, and 5–6 points indicate low self-esteem [35]. The Cronbach alpha coefficient for the Turkish form of the scale is 0.79. In this study, the internal consistency coefficient of the RSES was found to be 0.80.

The BDI was developed by Beck and colleagues to measure the level of depression in adults and to determine the severity and frequency of symptoms. The scale is a 4-point Likert-type scale consisting of 21 questions and is based on self-report of depression symptoms in the past two weeks. The scores range from 0 to 3, and the scores that can be obtained from the scale range from 0 to 63. Scores between 0 and 9 are interpreted as 'minimal level', scores between 10 and 16 as 'mild level', scores between 17 and 29 as 'moderate level' and scores between 30 and 36 as 'severe level' of depressive symptoms [36]. The internal consistency coefficient of the scale in the Turkish validity and reliability study was found to be 0.80. The Cronbach alpha coefficient of the scale used in this study is 0.86.

The BAI is a self-report scale designed to measure the frequency and severity of anxiety symptoms. The scale has 21 items and is a likert type scale scored from 0–3. The person is asked how much the statements in the scale items affect them and the person is asked to rate the items. The score that can be obtained from the scale ranges from 0–63 and an increase in the score indicates an increase in the severity of the anxiety. The Cronbach alpha internal consistency coefficient of the scale adapted to Turkish was found to be 0.93 [37]. In this study, the Cronbach alpha internal consistency coefficient of the scale was found to be 0.92.

Since this study involved human participants, ethical clearance was obtained from the institution to which one of the study authors is affiliated. The protocol for this study was approved by the Marmara University Human Research Ethics Committee (Report Date: 27 December 2022, report number: 2021–96, protocol number:2021–4/24). Additionally, this study was conducted in accordance with the ethical standards declared in the 1964 Declaration of Helsinki and subsequent updates. Professional ethical rules were followed throughout the research.

Data were collected online through the Google Forms application between April 2022 and August 2022 via the snowball sampling method on a voluntary basis. IBM SPSS 25.0 was used to analyse the data. The data collection process was conducted through social media due to the existing SARS-CoV-2 outbreak. Prior to the start of the study, participants were presented with an informed consent form, their consent to participate in the study was obtained, and they were informed that they could withdraw from the study at any time. No identity information other than that provided in the demographic information form was requested from the study participants, and it was explained that the participants would not be assessed individually and that the results would be analysed collectively. The participants were first asked to complete the demographic information form and the short form of the ORTO-11 and then, in random order, the short form of the EAT-26, the DERS-36, the RSES, the BDI, and the BAI. The scales took approximately 15–20 min to complete.

The data were analysed using IBM SPSS Statistics 25. Since the ORTO-11 scale, one of the measurement tools used in the study, did not have a sub-dimension, it was analysed based on the total score received by the participants. The other measure, EAT-26, was calculated by creating four separate score types, including the total score and three sub-dimensions (eating preoccupation, restriction, social pressure). The total score and six sub-dimensions of the DERS-36 were calculated in the same way. The other measures used, BDI, BAI and RSES, were included in the analysis by calculating only the total scores as they did not have sub-dimensions. Before analysing the data, responses from participants with extreme values were removed from the data set. Normality analyses were carried out to test the suitability of the data for the planned analyses. The normality of the comparisons in the study was determined using kurtosis and skewness analyses [38]. Total and subscale means, standard deviations, minimum and maximum scores of the scales used in the study and Cronbach alpha values for reliability were calculated. As the data showed a normal distribution, Pearson correlation analysis was used to determine the relationships between the scales used in the study. Multiple regression analysis was carried out to determine the predictive power of several independent variables (eating attitudes, difficulties in emotion regulation, self-esteem, depression and anxiety) on the dependent variable (orthorexia nervosa). After the multiple regression analysis, the hierarchical regression method was applied to the variables that were found to be significant in the regression analysis. In interpreting whether the results were significant, the 95% confidence interval and the 0.05, 0.01 levels of significance were used as criteria.

76.8% of the participants were graduates, 55.8% had one child, 72.6% were overweight according to their BMI calculations, 58.4% were unemployed, 81.1% described themselves as healthy, 58.9% were on regular/intermittent diets, 79.2% did not exercise regularly, 44.73% described themselves as overweight, 71.1% were not satisfied with their weight, 80.3% were careful to consume natural foods, 46.6% were normally careful about their diet, and 43.4% tried to change their behaviors in line with the information they received when they received information about nutrition. The demographic characteristics of the sample are given in Table 1.

Table 2 shows the results of Pearson correlation analysis to examine the relationships between ORTO-11, which assesses orthorexia nervosa, and other variables. A negative and moderate relationship was found between ORTO-11 and the total score for the EAT-26 (r = -0.407). A negative and moderate relationship was found with eating preoccupation (r = -0.336), and a negative and weak relationship with restriction (r = -0.267) and social pressure (r = -0.168), which are sub-dimensions of the EAT-26. A positive and weak relationship was found between ORTO-11 and BAI (r = 0.141). No relationship was found between ORTO-11 and difficulties regulating emotions, depression and self-esteem.

In Table 3, multiple linear regression analysis was designed to determine the predictive effects of eating attitudes, difficulties regulating emotions, depression, anxiety and self-esteem on orthorexia nervosa. The 'enter' regression method was used in the analysis. The established model was found to be statistically significant (F(3,374) = 17.018, p < 0.01). The model explained 18.5% of the variance in the orthorexia nervosa score. It was found that eating attitudes (β = -0.393, t = -8.223, p < 0.01), depression (β = 0.141, t = 2.371, p < 0.05) and anxiety (β = -0.147, t = -2.492, p < 0.05) scale scores were statistically significant predictors of orthorexia nervosa scores. The difficulties in emotion regulation and self-esteem scores were found to have no statistically significant predictive value.

In Table 4, to determine the predictive effect of eating attitude scores on orthorexia nervosa scores, some demographic variables were included in the model and a hierarchical regression analysis was designed. In the first step, the EAT-26, which was significant in the linear regression model, was included in the model. In the first step of the hierarchical regression, model 1, it was found that the constant term contributed to the model and that the EAT-26 scores (β = -0.224, t = -8.651, p < 0.01) statistically significantly predicted the ORTO-11 scores. The model explained 16.5% of the variance in ORTO-11 scores.

In a second step, the demographic variables that showed significance were included in the model. In model 2, the contribution of the constant term to the model was found to be significant. It was observed that attention to diet (β = 1.052, t = 3.980, p < 0.01), consumption of natural foods (β = 1.405, t = 2.941, p < 0.01) and behavioural changes after receiving information about proper nutrition (β = 1.322, t = 6.117, p < 0.01) also predicted orthorexia nervosa scores. However, it was found that body image, perceived weight, perception of health and whether or not on a diet did not predict orthorexia nervosa scores. It was observed that the final model explained 32.1% of the variance in the orthorexia nervosa scale scores. Therefore, it was found that the independent variables in Model 2 had a greater explanatory power for orthorexia nervosa than in Model 1.

The results of the correlational analysis of the study show that orthorexia nervosa is negatively and moderately related to the total eating attitude score and eating preoccupation; and negatively and weakly related to restraint and social pressure. Taken together, the results suggest that as individuals' disordered eating attitudes increase, their ORTO-11 scores decrease, and thus their propensity to develop orthorexia nervosa decreases. The results of the studies in the literature, which find a similar relationship between orthorexia nervosa and eating attitudes regardless of the sample group and measurement tools (ORTO-15 or EAT-40), support the result of the current study [39,40,41]. The relationship between orthorexia nervosa and eating pathology is explained in many ways. According to the results of the research, the EAT-26 is a measurement tool that is sensitive to disordered and disturbed eating, and it has been observed that orthorexia nervosa falls within the range identified as a suspected eating disorder according to the EAT-26 [13]. According to the results of the study conducted by Parra-Fernandez et al. (2018) to investigate the prevalence of orthorexia nervosa in a sample of university students in Spain and to identify the common features of orthorexia nervosa and eating disorders, many common aspects were found in eating disorders and people at risk of orthorexia nervosa [42]. The study found a negative and moderate relationship between eating preoccupation scores, one of the sub-dimensions of the Eating Attitude Scale, and Orthorexia Nervosa susceptibility. The reason why the relationship between orthorexia nervosa and the total eating attitude score and the eating preoccupation sub-dimension is very similar is that there is a very high correlation between the eating preoccupation dimension and the Eating Attitude Short Form. Therefore, it is stated that in cases where there is a time constraint to obtain a similar result, only the questions of the Eating Preoccupation dimension can be answered. In other words, the eating preoccupation sub-dimension is seen as a miniature version of the EAT-26 [31]. In a study by Dunn et al. (2019), which investigated whether the EAT-26 scale could detect a predisposition to orthorexia nervosa, they obtained a very high score from the eating preoccupation sub-dimension. In other words, as the eating preoccupation score increases, so does the predisposition to orthorexia nervosa (there is a negative relationship between them) [13]. This subscale generally includes questions that express strict rules about diet. It is known that people with a high predisposition to orthorexia nervosa tend to have a strict diet in terms of consuming pure and healthy foods. Therefore, this result is not surprising. It was observed that there was a negative weak correlation between the restraint dimension, another subscale of the Eating Attitude Scale, and the tendency to orthorexia nervosa. In the literature review, it was found that the increasing tendency to orthorexia nervosa was also related to the restraint subscale, in addition to the total score of the eating attitude and the eating preoccupation subscale, which supports the result of the study [17]. Finally, it was observed that there was a negative weak correlation between the social pressure subscale, the third subscale of the short form of eating attitudes, and the orthorexia nervosa scores. There are studies in the literature that report that as the tendency to orthorexia nervosa increases, the scores of the social pressure subscale of eating attitudes increase within the limits of weak correlation [10].

The results of the regression analysis showed that orthorexia nervosa was statistically significantly predicted by disordered eating, depression and anxiety. According to the regression analysis results of the study, when the t-score was taken into account, it was found that disturbed eating attitude was the most predictive variable of orthorexia nervosa. It was also found that the power of depression and anxiety to explain orthorexia nervosa, while explaining the variance of orthorexia nervosa, was much lower than that of eating attitudes. The Eating Attitude Scale was the strongest predictor of the sample's predisposition to orthorexia nervosa. In line with these findings, disturbed eating attitudes can be interpreted as a risk factor that increases orthorexia nervosa. There are many studies in the literature that support this result of the study [43,44,45,46]. According to the study conducted by Farchakh et al. (2019) to understand the relationship between orthorexia nervosa tendency and eating attitude and anxiety in Lebanese medical students, it was found that disturbed eating attitude predicted orthorexia nervosa [24]. Similarly, according to the results of a study conducted on university students in Turkey, it was found that increasing disturbed eating attitude predicted orthorexia nervosa tendency [41]. A study was conducted by Segura-Garcia et al. (2015) to investigate the level of orthorexia nervosa in eating disorder patients known to have anorexia nervosa and/or bulimia nervosa after treatment, in order to determine the tendency of patients diagnosed with eating disorders to orthorexia nervosa. According to the research results, orthorexia nervosa is a condition that is comorbid in 28% of anorexia nervosa and bulimia nervosa patients at the time of their first contact with a health care facility. Furthermore, during the follow-up studies 3 years after the treatment of eating disorders, it was found that anorexia nervosa and bulimia nervosa decreased, but orthorexia nervosa gradually increased [47]. It is important to note that although it was expected that the tendency to orthorexia nervosa would decrease after treatment for the eating disorder, on the contrary, it increased. The authors explained this by saying that orthorexia nervosa may occur during the treatment of anorexia nervosa and may be a transitional phase [47]. In another study conducted in a similar way, it was observed that patients with high orthorexia nervosa tendency felt more competent and satisfied with the situation during their treatment. It is stated that orthorexia nervosa may be a coping strategy of individuals with anorexia nervosa [15]. In the study conducted by Strahler et al., it was reported that individuals with orthorexia nervosa tendency were 78% more likely to meet the criteria for an eating disorder than those without [23]. It has also been stated that the healthy eating characteristics of orthorexia are more socially acceptable compared to other eating disorders, which is important in terms of making socially excluded eating disorder sufferers more acceptable. Because of these characteristics, orthorexia nervosa has been described as 'a disease disguised as a virtue' [3]. Taken together, the study results suggest that disturbed eating attitudes are one of the risk factors associated with orthorexia nervosa.

The study found that another predictor of orthorexia nervosa was anxiety and depression. This finding can be interpreted as an increase in anxiety levels may increase susceptibility to orthorexia nervosa and that anxiety also has an effect on the variance in explaining orthorexia nervosa symptomatology. There are studies that support the findings of the study: One study found that depression and anxiety play a mediating role between impulsivity and orthorexia [18]. In addition, Yılmaz and Dündar (2022) reported in their study that an increase in anxiety symptoms increases the risk of orthorexia nervosa [10]. In their study, Valente et al. (2020) found that anxiety and perfectionism may be effective in the development of orthorexia nervosa [25]. A perfectionist person tries to keep everything under control, but anxiety occurs in situations where they cannot keep it under control. Sudden life events (e.g. sudden weight loss) that occur in life trigger anxiety by creating a lack of control in the individual. Therefore, people may use 'food as medicine' to alleviate their anxiety (Valente et al. 2020:5). Another variable that predicts susceptibility to orthorexia nervosa in the study is depression. One of the findings of the current study is that susceptibility to orthorexia nervosa increases as the severity of depression increases. Studies have reported that individuals with severe depression have a 2.40 times higher risk of orthorexia nervosa [48], and orthorexia nervosa is more associated with depressive symptoms than healthy orthorexia nervosa [49]. In Awad's study, it was reported that as people's depression levels increase, the likelihood of developing orthorexia nervosa increases at the same rate [18].

In the hierarchical regression analyses of the study, it was concluded that the demographic variables included in the study, such as paying attention to diet, consuming natural foods, and translating this information into behaviour when receiving accurate information, had a significant predictive effect on orthorexia nervosa. When these variables were included in the model, they were found to explain 32.1% of the variance in orthorexia nervosa together with the other independent variable, eating attitudes. The results can be interpreted as meaning that the consumption of natural foods, attention to diet and positive changes in behaviour in the context of accurate information are risk factors for the increase in orthorexia nervosa. The results of the analysis are supported by the literature. In a study that examined the predisposition of mothers with 0–2 year old children to orthorexia nervosa, it was found that the excessive preoccupation of mothers with nutrition increased the likelihood of developing an eating disorder [15]. A study reported that in cases of orthorexia nervosa, when eating discipline is disrupted, the tendency to become more preoccupied with pure and natural foods to compensate increases [4], and that when an individual cannot maintain their diet as desired, they may try to repair this behaviour by paying more attention to nutrition. The finding that individuals' propensity for orthorexia nervosa increases with increasing consumption of natural foods is consistent with the knowledge that one of the most important factors among the proposed diagnostic criteria for orthorexia nervosa is an excessive preoccupation with food purity. The following adjectives are frequently used in relation to food when describing orthorexia nervosa: healthy / organic / pure / safe food [29]. In addition, as a result of all the studies conducted on orthorexia nervosa, it has been stated that the main difference of the obsession with healthy eating from other eating disorders is that it does not focus on the quantity of food, but on the purity and quality of food [50, 51]. According to the results of the study conducted by Bosi et al. (2007), it was found that participants who care about the quality of food and individuals who look at the content of a food when buying it are more prone to orthorexia nervosa [52]. In addition, the study's conclusion that when correct information is received, the tendency to orthorexia nervosa increases as the change in behaviour around correct information increases, is one of the findings supported in the literature. In the study conducted by Yüksel (2017) to investigate the tendency to orthorexia nervosa, it was observed that as the education and information received about healthy nutrition and healthy food increases, so does the preoccupation with orthorexia nervosa [53]. Studies comparing health-related professionals/students with professionals/students who have not received health and nutrition training show that those who have received training in healthy eating are more susceptible to orthorexia nervosa [2, 52, 54]. This can be expressed as an increased focus on healthy and proper nutrition, which can be a risk factor for orthorexia nervosa. The reason for this behaviour may be that better knowledge of the effects of nutrition on health makes individuals more sensitive to these issues.

The study has a number of limitations. The first is that the sample was selected from female participants only. Future studies may include male participants to obtain comparable results and to assess the role of gender in orthorexia nervosa.

Another limitation is that the Cronbach alpha value of the ORTO-11 scale used to assess orthorexia nervosa was found to be 0.59. It should be noted that the results obtained may have been influenced by this value, as the value was below 0.60. It is recommended that future studies use other scales related to orthorexia nervosa and compare the results obtained.

In addition, the BMI was calculated by the researcher using the weight and height measurements taken from the participants during the study. The BMI values are the values reported by the participants. These were accepted as correct, but no information was obtained from the participants about when these measurements were last taken. Therefore, there may have been a bias depending on the participant's recall.

The research data was collected online and via Google Forms due to the ongoing COVID-19 pandemic. Verification questions were used in the transitions of the scale questions to increase reliability in Google Forms. However, the fact that the data was collected online and via social media with social media users and online savvy individuals may have affected the reliability of the results obtained. Face-to-face data collection is recommended for future studies.

The study found that the most important factor in predicting orthorexia nervosa was eating attitudes. Therefore, future studies should examine the effects of other eating disorder predictors on orthorexia nervosa in order to understand the dynamics of orthorexia nervosa.

As a result of the study, the relationship between difficulties in emotion regulation and self-esteem in orthorexia nervosa is not fully understood in the current sample. In order to clarify these dynamics, studies are needed on the explanatory power of the indirect effects of emotion regulation and self-esteem on eating attitudes in orthorexia nervosa.

Download references

EY: Conceptualisation, methodology, formal analysis, investigation,resources,writing—original draft preparation,writing—review and editing,visualisation,supervision. ŞD: formal analysis,investigation,resources. TGB: formal analysis,investigation,resources.

Correspondence to Elif Yöyen.

The protocol for this study was approved by the Marmara University Human Research Ethics Committee (Report Date: 27 December 2022, report number: 2021–96, protocol number:2021–4/24). The study was performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its following updates. Informed consent was obtained from all the individual participants that were included in the study.

Not applicable.

Not applicable.

The authors declare no competing interests.

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.

Reprints and permissions