Strict health-oriented eating patterns (orthorexic eating behaviours) and their connection with a vegetarian and vegan diet

Abstract

Purpose
Although research on vegetarianism is becoming more prevalent, to date, only a few research has been conducted on relationship between vegetarian diet and orthorexia nervosa (ON). The objective of the present study was to examine the orthorexic dietary patterns and eating behaviours among individuals following a vegetarian, vegan, and meat diet. We examined the moderating role of ethical and health reasons for following a meat-free diet on the relation between vegan versus vegetarian diet and eating behaviours and ON. The study aimed to determine the predictors of ON in individuals with differential food preferences.

Methods
Seventy-nine individuals following a meat-free diet and 41 individuals following an omnivore diet completed the EHQ and the TFEQ-R18.

Results
Our findings indicated that individuals following a vegan diet showed a higher level of knowledge of healthy eating than those who followed a vegetarian diet and those who followed an omnivore diet. Participants maintaining a vegan diet for health reasons were more likely to have greater knowledge about healthy eating. Cognitive restraint was a predictor of ON among a sample following a meat-free diet.

Conclusions
Our results could contribute to identify potential risk factors for strict health-oriented eating patterns and to gain a better insight into ON.

Level of evidence
Level V, descriptive study.

Full text

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Eating and Weight Disorders - Studies on Anorexia, Bulimia and Obesity (2019) 24:441–452
https://doi.org/10.1007/s40519-018-0563-5
ORIGINAL ARTICLE
Strict health-oriented eating patterns (orthorexic eating behaviours)
andtheir connection withavegetarian andvegan diet
AnnaBrytek‑Matera1 · KamilaCzepczor‑Bernat2· HelenaJurzak1· MonikaKornacka3· NataliaKołodziejczyk2
Received: 6 July 2018 / Accepted: 13 August 2018 / Published online: 29 August 2018
© The Author(s) 2018
Abstract
Purpose Although research on vegetarianism is becoming more prevalent, to date, only a few research has been conducted
on relationship between vegetarian diet and orthorexia nervosa (ON). The objective of the present study was to examine
the orthorexic dietary patterns and eating behaviours among individuals following a vegetarian, vegan, and meat diet. We
examined the moderating role of ethical and health reasons for following a meat-free diet on the relation between vegan
versus vegetarian diet and eating behaviours and ON. The study aimed to determine the predictors of ON in individuals with
differential food preferences.
Methods Seventy-nine individuals following a meat-free diet and 41 individuals following an omnivore diet completed the
EHQ and the TFEQ-R18.
Results Our findings indicated that individuals following a vegan diet showed a higher level of knowledge of healthy eating
than those who followed a vegetarian diet and those who followed an omnivore diet. Participants maintaining a vegan diet
for health reasons were more likely to have greater knowledge about healthy eating. Cognitive restraint was a predictor of
ON among a sample following a meat-free diet.
Conclusions Our results could contribute to identify potential risk factors for strict health-oriented eating patterns and to
gain a better insight into ON.
Level of evidence Level V, descriptive study.
Keywords Orthorexia nervosa· Vegetarian diet· Vegan diet· Eating behaviours
Introduction
Vegetarianism is defined as the practice of abstaining from
eating meat [1] based mainly on ethical, but also health-
related, aspects [2]. In the literature, one can find a hypoth-
esis that orthorexic eating behaviour might appear more
often among vegetarians than among people without spe-
cific dietary habits [3, 4]. However, only a few studies have
explored this hypothesis [2, 5–8]. Moreover, the literature
on the link between a vegetarian diet and orthorexia seems
to lack consensual results, and research assessing what fea-
ture of orthorexic or maladaptive eating behaviour might be
linked to specific vegetarian eating habits is still missing.
Orthorexia nervosa (ON) is defined as a fixation on
health-conscious eating behaviour [9]. The first (formal)
diagnostic criteria was developed by Moroze etal. [10].
Recently, Dunn and Bratman [11] proposed more detailed
classification criteria (Table1).
These reported criteria are new diagnostic criteria for ON,
achieved after a critical review of published case histories,
eating disorders professionals’ narrative descriptions, and
numerous self-reports of orthorexia nervosa sending to Brat-
man’s website [11]. The previous criteria described by Brat-
man and Knight [12] have not been identified empirically,
This article is part of the topical collection on Orthorexia Nervosa.
* Anna Brytek-Matera
abrytek-matera@swps.edu.pl
1 Katowice Faculty ofPsychology, SWPS University ofSocial
Sciences andHumanities, Technikow 9, 40-326Katowice,
Poland
2 Interdisciplinary Doctoral Studies, Wroclaw Faculty
ofPsychology, SWPS University ofSocial Sciences
andHumanities, Wroclaw, Poland
3 Faculty ofPsychology, SWPS University ofSocial Sciences
andHumanities, Warsaw, Poland
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442 Eating and Weight Disorders - Studies on Anorexia, Bulimia and Obesity (2019) 24:441–452
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and it has not been empirically proven that they represent a
co-occurring pattern of behaviours [13].
Although ON cannot be considered as a diagnostic cat-
egory and still needs to be recognized as neither DSM-5
nor ICD-10 do not consider it as a syndrome, orthorexic
behaviour can represent an important limitation in everyday
life deeply affecting the quality of life. ON starts out as an
innocent attempt to obtain optimum health through diet, but
it finally leads to unintended negative consequences such as
malnutrition, impaired social life, deterioration of the qual-
ity of life, and well-being [14, 15]. Diet becomes essential
part of people’s thoughts and concerns and leads to dietary
restrictions, excessive focus on food-related topics, lack of
enjoyment of food, gaining control over food intake, rigid
eating behaviours, and ritual actions involving food prepa-
ration [16–18]. Individuals with ON desire to improve self-
esteem and self-realization through controlling food intake
[19]. Sometimes, all behaviours may be associated with
unintentional weight loss, with no desire to lose weight (los-
ing weight is subordinated to ideation about healthy food).
To sum up, ON include abnormal (compulsive) behaviours
or mental preoccupations with dietary choices believed to
promote optimal health, self-imposed anxiety, self-punish-
ment, and escalating severe restrictions [20].
Numerous prospective cohort studies and randomized
clinical trials have shown the various health benefits of the
vegetarian diet [21]. It is well known that a meat-free diet
requires a well-balanced diet, including supplements or
fortified products [22]. The Loma Linda University (LLU)
Vegetarian Food Guide Pyramid [21] consists of both diet
and lifestyle recommendations for a well-planned vegetarian
diet (see Fig.1).
Despite existing guidelines on a healthy vegetarian diet,
the intake of a proper well-balanced and well-planed diet
may prove difficult for some individuals following a meat-
free diet. Research has suggested an association between
vegetarianism and disordered eating behaviours (lifetime
and current eating disorders) [3, 4]. Vegetarian diets may be
used to legitimize food avoidance and avoidance of certain
eating situations to facilitate ongoing restriction and disguise
restrictive eating patterns employed to control weight [3].
The higher incidence of eating disorders relating to vegetari-
anism suggests that special diets (pescatarian, vegan, paleo,
gluten-free and raw diet) may be connected to disordered
eating behaviours and serve as socially acceptable means to
mask disordered eating behaviours [4]. Research has shown
that women following a vegetarian diet may be more likely
to display disordered eating attitudes and behaviours than
women following a meat diet [23] as well as men [24].
In addition, following specific diets or food rules, such
as a vegetarian, vegan, fructarian (fruitarian) or crude diet
(raw food diet), were found to be associated with orthorexic
dietary patterns [2, 5–8]. A vegetarian or vegan diet might be
a contributing factor for the onset of orthorexia nervosa. The
permanent reduction of “allowed” foods might contribute
to a diet that consists of very few foods considered comesti-
ble; consequently, individuals might restrict their diet from
omnivore to vegetarian and finally to vegan [12].
Analysis of orthorexic eating behaviour reveals several
overlapping characteristics with vegetarianism, veganism
and dieting behaviour (see Fig.2). It is worth pointing out
that while there are several assumptions regarding the con-
nection between a meat-free diet and orthorexic dietary pat-
terns, there are no published data confirming those similari-
ties [2].
Adherence to a vegetarian diet has been hypothesized to
be a factor in the onset and maintenance of disordered eat-
ing behaviour; however, evidence to support this assumption
has been largely inconsistent [25]. Some studies found that
individuals following a vegetarian or vegan diet were more
likely to have orthorexic eating behaviour than individuals
on a mixed diet [4, 26, 27], while other results reported that
Table 1 Classification criteria for orthorexia nervosa by Dunn and Bratman [11]
Criterion A: Obsessive focus on “healthy” eating, as defined by a dietary theory or set of beliefs whose specific details may vary; marked by
exaggerated emotional distress in relationship to food choices perceived as unhealthy; weight loss may ensue as a result of dietary choices, but
this is not the primary goal. As evidenced by the following:
A1. Compulsive behaviour and/or mental preoccupation regarding affirmative and restrictive dietary practices believed by the individual to
promote optimum health
A2. Violation of self-imposed dietary rules causes exaggerated fear of disease, sense of personal impurity and/or negative physical sensations,
accompanied by anxiety and shame
A3. Dietary restrictions escalate over time, and may come to include elimination of entire food groups and involve progressively more frequent
and/or severe “cleanses” (partial fasts) regarded as purifying or detoxifying. This escalation commonly leads to weight loss, but the desire to
lose weight is absent, hidden or subordinated to ideation about healthy eating
Criterion B: The compulsive behaviour and mental preoccupation becomes clinically impairing by any of the following:
B1. Malnutrition, severe weight loss or other medical complications from restricted diet
B2. Intrapersonal distress or impairment of social, academic or vocational functioning secondary to beliefs or behaviours about healthy diet
B3. Positive body image, self-worth, identity and/or satisfaction excessively dependent on compliance with self-defined “healthy” eating
behaviour
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443Eating and Weight Disorders - Studies on Anorexia, Bulimia and Obesity (2019) 24:441–452
1 3
those who followed a vegan diet presented a less pathologi-
cally strict health-oriented eating pattern than those follow-
ing a meat diet [28], highlighting once again the gap in the
literature on the relationship between a vegetarian diet and
orthorexia nervosa. Although research on vegetarianism and
veganism is becoming more prevalent, to date, only a few
research studies have been conducted to explore this rela-
tionship. There has been only one study focusing on ortho-
rexic and restrained eating behaviour in a sample of vegans
and vegetarians [2]. The objective of the present study
was to examine the orthorexic dietary patterns and eating
behaviours among individuals with differential food prefer-
ences (vegetarian, vegan, and meat diet). In addition, we
aimed to analyse the moderating role of ethical and health
reasons for following a meat-free diet on the relationship
between vegan versus vegetarian diet and eating behaviours
and orthorexia nervosa. The assumption of the moderating
role of reasons for following a meat-free diet was based on
Fig. 1 Vegetarian food guide pyramid guidelines for healthful vegetarian diets [21]. Note: We received the written permission from the authors
for using the LLU Vegetarian Food Guide Pyramid in the present manuscript
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444 Eating and Weight Disorders - Studies on Anorexia, Bulimia and Obesity (2019) 24:441–452
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a recent research [2] showing that individuals who restrict
their eating behaviour predominantly due to ethical reasons,
display more orthorexic eating behaviour than individuals
not limiting their food consumption. Moreover, in a sample
of vegans, only health-related motives were associated with
orthorexic eating behaviour, contrary to the ethical reasons.
Those results indicate that motives and beliefs might moder-
ate the effect of following meat-free diet on ON behaviours
[2]. The current literature is lacking of research indicating
predictors of ON in individuals following a meat-free diet.
Therefore, this study aimed also to determine the predictors
of cognitions, behaviours, and feelings related to orthorexia
nervosa in individuals with differential food preferences.
On the basis of the literature [2], we put forward the fol-
lowing hypotheses:
H1: Individuals following a vegetarian diet and/or a vegan
diet present a higher level of orthorexic behaviours com-
pared to the individuals following a meat diet.
H2: Individuals following a vegan diet have a greater level
of knowledge about healthy eating than those following a
vegetarian diet. This effect is moderated by the reason for
choosing a meat-free diet (ethical versus health).
H3: Cognitive restraint is a predictor of a strict health-
oriented eating pattern among individuals following a
vegetarian and/or vegan diet.
Materials andmethods
Participants followingavegetarian diet, avegan
diet, andcontrol group
The vegan and vegetarian sample was selected from 321
individuals following a meat-free diet who applied to partici-
pate in the study. Of this number, 105 individuals (32.71%)
completed the online survey. This sample consisted of
those following a semi-vegetarian diet (7.62%), a vegetar-
ian diet (47.62%), a vegan diet (40.95%), and a raw food
diet (3.81%). The eligibility criteria for the sample with a
meat-free diet are presented in Fig.3.
To divide each sample into subgroups, participants had to
answer several questions regarding their eating behaviours
(e.g., how often they eat red meat, poultry, fish and seafood,
milk and dairy products, eggs, fruits, vegetables, grain prod-
ucts, and oil on a 5-point scale from ‘never’ to ‘every day’).
Furthermore, participants were asked to identify themselves
as one of the following: semi-vegetarian, vegetarian, vegan,
fruitarian or raw food diet.
Referring to the recent research [2], which highlighted
the important role of the reasons for beginning and preserv-
ing a vegetarian and vegan diet, we took into consideration
these variables in our study. The sample was divided into
two groups: ethical aspect (e.g., ethics, religion, value sys-
tem, and environmental concerns) versus health causes (e.g.,
health and losing weight).
The control group consisted of 41 individuals following
an omnivore diet (consumption of fruits, vegetables and ani-
mal products and meat).
Procedure
Data of samples were collected via online survey. Partici-
pants were recruited via direct interpersonal contact (e.g.,
in vegetarian restaurants and vegetarian meetings), posters
(about project), and vegetarian social networking sites. Par-
ticipants from the control group were recruited using the
same procedure in the places not linked to vegetarian/vegan
lifestyle. All participants gave their permission to be part
of the study, and they provided informed voluntary written
consent prior to initiating the survey via an online consent
form. Participants completed a series of measures (described
below). They were informed that their participation was vol-
untary and anonymous. Furthermore, all participants had the
Fig. 2 Similarities between
vegetarian diet and orthorexia
nervosa
VEGETARIAN
DIET
Preoccupation with
consuming meat-free
meals (the main goal:
very often ethical reason)
SIMILARITIES
Specific food selection (consuming
healthy and organic food)
Making eating-related issues an important
area of one’s own life
Focusing on quality of food intake
Reduction of food intake according to
specific nutrition rules
Nutrition rules specifying which foods are
“allowed” and which are “forbidden
Rigid food rules and an inability to remain
flexible in one’s eating habits.
ORTHOREXIA
NERVOSA
Preoccupation with
consuming healthy and
pure foods (the main goal:
being healthy)
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445Eating and Weight Disorders - Studies on Anorexia, Bulimia and Obesity (2019) 24:441–452
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right to refuse to participate without penalty if they wished
(at any time and for any reason, they could refuse to answer
a question or stop filling out the questionnaire and not send
their data using the ‘send’ button). The touch pen (worth
approximately €6.00) was compensation for participation
in the research. No other compensation was offered. The
study protocol was approved by the SWPS University of
Social Sciences and Humanities Human Research Ethics
Committee (no. WKEB45/03/2017). The research project
was funded by the National Science Centre (NCN), Poland
(Grant no. 2017/01/X/HS6/00007). The current study is part
of a large project focusing on the assessment of rumination
and eating behaviours in daily life among individuals with
differential food preferences (following a meat-free diet).
Measures
The Eating Habits Questionnaire (EHQ)
An challenge for research exploring the link between spe-
cific dietary habits and orthorexic behaviours is the valid
evaluation of orthorexia nervosa. Bratman created the
Orthorexia Self-Test, labelled by the author as “a ten-ques-
tion quiz to determine if you have orthorexia” [12; p.47].
The necessary psychometric properties, namely, reliability
and validity, of this test were not evaluated. Moreover,
neither the cut scores of a reference group was assessed
[11]. It was designed as a screening instrument (as an
informal measure), with items such as: ‘Do you spend
more than 3h a day thinking about healthy food?’ or ‘Does
your diet socially isolate you?’. The Orthorexia Self-Test,
however, has been the basis of the ORTO-15, ‘a question-
naire for the diagnosis of orthorexia nervosa’ [29, p.e28].
Nowadays, the ORTO-15 is probably the most widely used
self-report measure of orthorexia nervosa. Although pre-
liminary validation has shown that the ORTO-15 has good
predictive validity [29], a low reliability has been ascribed,
and the internal consistency of the ORTO-15 has been
criticized [14]. There are many possible objections to the
ORTO-15 test reliability [11, 26], e.g., high prevalence
rates of ON among different research populations, lack
of clearly articulated development of construct validity,
lack of discussion about the creation of an item pool, lack
of standardization methods, and lack the basic psycho-
metric properties [11], suggesting caution in the usage of
the ORTO-15 test to reliably measure the prevalence of
ON. Dunn etal. [28] consider that the ORTO-15 likely
cannot distinguish between healthy eating and pathologi-
cally healthful eating. In addition, according to Dunn and
Bratman [10], the ORTO-15 is likely to measure healthy
eating, but it is not feasible to more accurately and fully
capture pathology. Therefore, taking into consideration all
Fig. 3 Eligibility criteria for
the special diet sample research
in the first study. Note: 1The
reason participants were
excluded due to “consistency
of self-defined types of diet
and objective criteria” was
following: discrepancy between
self-description of the diet and
self-identification as one of the
following: vegetarian or vegan
(e.g., those who described
themselves as vegetarians and
declared to often eat fish were
eliminated). The procedure was
based on Barthels’ etal. [2] cri-
teria: vegetarianism: exclusion
of meat from the diet; vegan-
ism: exclusion of all animal
products from the diet
Semi-vegetarian
diet
N = 8
Vegetarian
diet
N = 50
First eligibility
criterion:
samples > 30
Vegan diet
N = 43
Raw food diet
N = 4
Vegetarian
diet
N = 50
Vegan diet
N = 43
Second eligibility criterion:
consistency of self-defined
types of diet and objective
criteria1
Sampling N = 321
Vegetarian
diet
N = 39
Vegans
N = 40
Participants (diet groups) N = 105
Filling in the
online survey
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446 Eating and Weight Disorders - Studies on Anorexia, Bulimia and Obesity (2019) 24:441–452
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listed limitations, in the present study, we used the Eating
Habits Questionnaire [13], a new research tool, developed
independently of the ORTO-15, for the measurement of
orthorexia nervosa.
The Eating Habits Questionnaire [13] assesses cogni-
tions, behaviours, and feelings related to an extreme focus
on healthy eating, which has been called orthorexia ner-
vosa. This 21-item self-report inventory measures the fol-
lowing symptoms of orthorexia nervosa: (a) knowledge of
healthy eating (5 items, e.g., ‘The way my food is prepared
is important in my diet’; α = 0.90); (b) problems associated
with healthy eating (12 items, e.g., ‘I have difficulty find-
ing restaurants that serve the foods I eat’; α = 0.82); and (c)
feeling positively about healthy eating (4 items, e.g., ‘I have
made efforts to eat more healthily over time’; α = 0.86). In
the present study, the EHQ was translated from English to
Polish using a standard forward–backward translation pro-
cedure. The English version of the EHQ was first translated
into Polish (by two translators who independently translated
the same questionnaire) and then back-translated into Eng-
lish (by two independent native English speakers without
reference to the English original). In the present study, the
Cronbach’s α values of the three subscales were: 0.81 for
knowledge of healthy eating, 0.82 for problems associated
with healthy eating and 0.70 for feeling positively about
healthy eating.
The Three-Factor Eating Questionnaire (TFEQ-R18)
The TFEQ-R18 measures eating behaviours [30]. It contains
18 items that constitute 3 domains: cognitive restraint (6
items, e.g., ‘I consciously hold back at meals in order not
to weight gain’), uncontrolled eating (9 items, e.g., ‘Some-
times when I start eating, I just can’t seem to stop’), and
emotional eating (3 items, e.g., ‘When I feel blue, I often
overeat’). In the present study, we used the Polish version of
the questionnaire [31], which has demonstrated satisfactory
levels of internal reliability (α = 0.78 for cognitive restraint,
α = 0.84 for uncontrolled eating and α = 0.86 for emotional
eating). In the present study, the Cronbach’s α values of the
three subscales were: 0.77 for cognitive restraint, 0.86 for
uncontrolled eating and 0.88 for emotional eating.
Data analysis
The Statistical Package for Social Sciences (version 22.0)
was used for variance, moderating and regression analy-
sis. One-way ANOVA with factor group for independent
samples (vegetarian diet versus vegan diet versus control
group) was taken, and post hoc tests with Bonferroni cor-
rection were used. The PROCESS macro [32] with bootstrap
N = 10,000 was used to analyse the moderating effects. Sub-
sequently, a multiple linear regression was used for analysis
of the predictors in samples with a meat-free diet (vegetar-
ians and vegans groups).
Results
Participant characteristics
Detailed characteristics of participants are presented in
Table2.
There were no differences between the vegan and veg-
etarian sample and the control group (following an omni-
vore diet) in terms of gender [F(2,117) = 2.33, p > 0.05,
η2 = 0.038], age [F(2,117) = 1.71, p > 0.05, η2 = 0.028] and
body mass index [F(2,117) = 1.03, p > 0.05, η2 = 0.017].
Variance analysis: orthorexia nervosa andeating
behaviours
The results of the one-way ANOVA with group (vegan,
vegetarian, and control) as an independent variable and
EHQ dimensions as the outcome indicates that there is a
significant group difference in orthorexia nervosa, espe-
cially in the particular dimensions linked to healthy eat-
ing, F(2,117) = 11.59, p < 0.001, η2 = 0.165; knowledge of
healthy eating, F(2,117) = 19.35, p < 0.001, η2 = 0.249 and
feeling positively about healthy eating, F(2,117) = 6.42,
p < 0.01, η2 = 0.099 (see Fig.4).
There were no significant differences between the groups
in the dimensions of the TFEQ-18, namely: cognitive
restrain, F(2,117) = 1.60, p > 0.05, η2 = 0.027; emotional eat-
ing, F(2,117) = 0.350, p > 0.05, η2 = 0.006 and uncontrolled
eating, F(2,117) = 1.58, p > 0.05, η2 = 0.026 (see Fig.5).
Moderating role ofthereason
forfollowingaspecific diet
To explore the moderating role of the reason for follow-
ing a vegetarian diet as suggested by Barthels etal. [2],
we performed a series of moderation models using Pro-
cess plug-in software for SPSS [32]. The lower level con-
fidence interval and the upper-level confidence interval
for unconditional effects are presented in square brackets.
This method of moderation analysis was chosen because of
the unequal distribution of the participants in the variable
reason for following a meat-free diet (health versus ethics)
and, consequently, a lack of satisfying assumptions for
performing the analysis of variance. The results suggest a
significant moderation model with the type of diet (veg-
etarian versus vegan) as a predictor, reasons for following
this diet as a moderator and EHQ knowledge of healthy
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447Eating and Weight Disorders - Studies on Anorexia, Bulimia and Obesity (2019) 24:441–452
1 3
eating as an outcome variable (R = 0.39; F(3,71) = 4.19;
p < 0.008; MSE = 7.98). The conditional effect of diet
type on EHQ knowledge of healthy eating was signifi-
cant for participants following the diet for health-related
reasons (B = 2.56; [0.84, 4.28]; p = 0.004); this effect was
not significant for participants following a meat-free diet
for ethical reasons (B = 0.56; [− 0.15, 1.27]; p = 0.12). The
moderation effect is presented in Fig.6. The conditional
process models with other dimensions of the EHQ or the
TFEQ-18 as outcomes were not significant.
Regression analysis: orthorexia nervosa andeating
behaviours amongindividuals followingameat‑free
diet
The predictor analysis of an extreme focus on healthy eating
indicates significant models for all symptoms of orthorexia
nervosa (entered into the model separately): problems asso-
ciated with healthy eating, F(6,72) = 4.12, p < 0.001, knowl-
edge of healthy eating, F(6,72) = 3.29, p < 0.01 and feeling
positively about healthy eating, F(6,72) = 5.22, p < 0.001
(see Table2). A multiple linear regression was used to ana-
lyse the predictors. The dichotomous variable (vegan versus
vegetarian diet) was subjected prior to analysis (Table3).
Discussion
The first objective of the present study was to assess the
orthorexic dietary patterns and eating behaviours among
individuals with differential food preferences. Our results
suggested that individuals who followed a special diet (veg-
etarian and vegan diet) reported more orthorexic behaviours
(knowledge of healthy eating, problems associated with
Table 2 Sample characteristics Vegetarian diet
N = 39
Vegan diet
N = 40
Omnivore diet
N = 41
M (SD)
Age 26.54 (8.07) 29.72 (10.75) 30.27 (10.04)
Body mass index (kg/m2) 21.78 (2.45) 21.72 (4.09) 23.11 (7.01)
Duration of diet (in months) 76.20 (105.15) 45.95 (66.17) n/a
N (%)
Body mass index
Underweight 2 (5.13) 6 (15.00) 4 (9.76)
Normal body
Weight 35 (89.74) 27 (67.50) 26 (63.41)
Overweight 2 (5.13) 7 (17.50) 6 (14.63)
Obesity 0 (0) 0 (0) 5 (12.20)
Weight loss methods
Yes
Diet 3 (7.69) 3 (7.50) 4 (9.76)
Physical activity 9 (23.08) 6 (15.00) 10 (24.39)
Laxatives 0 (0) 0 (0) 0 (0)
Vomit 0 (0) 0 (0) 0 (0)
Starvation diet 0 (0) 0 (0) 0 (0)
No 27 (69.23) 31 (0) 27 (65.85)
Daily weighing
Yes 0 (0) 1 (2.50) 4 (9.76)
No 39 (100) 39 (97.50) 37 (90.24)
Note: *p < .05, **p < .01, *** p < .001 , ns - nonsi
g
nificant
0
5
10
15
20
25
30
EHQ
Problems
EHQ
Knowledge
EHQ
Feelings
**
ns ***
**
***
*
ns
**
*
Vegetarian diet Vegan diet Control group
Fig. 4 Means and standard error of the symptoms of orthorexia ner-
vosa as measured by the Eating Habit Questionnaire (EHQ)
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448 Eating and Weight Disorders - Studies on Anorexia, Bulimia and Obesity (2019) 24:441–452
1 3
healthy eating and feeling positively about healthy eating)
than those who followed no special diet; thus, Hypothesis1
was confirmed. An extreme focus on healthy eating is asso-
ciated with special eating behavioural features: vegetarian
and vegan diet. Our results are compatible with the findings
of Barnett etal. [4]. The recent study has also shown that
a meat-free diet, lower educational attainment and higher
depressive symptoms were associated with a higher rate of
orthorexic behaviour [33]. Vegetarians and vegans exhibit
higher ON tendencies than individuals on a mixed diet,
which may indicate that individuals with ON tendencies
are more likely to be on a vegetarian or vegan diet [26].
The authors argue that being on a vegetarian diet requires a
fair degree of self-discipline, planning, and cognitive pro-
cessing related to eating behaviour. In the literature, we can
also find results indicating no significant difference in an
extreme focus on healthy eating (also in attitudes to eating
and obsessive symptoms) between the individuals following
a vegetarian or vegan diet and individuals consuming meat
[34]. Thus, Çiçekoğlu and Tunçay [34] state that veganism
and/or vegetarianism is not associated with an obsession
with healthy eating.
Our study showed that individuals who followed a veg-
etarian or vegan diet did not differ in problems associated
with healthy eating and feeling positively about healthy
eating. Thus, there is no difference between these groups
in turning down social events that involve eating unhealthy
food; following a diet with many rules; being distracted
by thoughts of eating healthily; eating only what their diet
allows; considering their healthy eating as a source of stress
in their relationship; considering their diet affects the type of
employment they would take; having difficulty finding res-
taurants that serve the foods they eat; having few foods that
are healthy for them to eat; going out less, since they began
eating healthily and spending more than 3h a day thinking
about healthy food and following a health-food diet rigidly
(items associated with problems with healthy eating). In
addition, the study did not show significant between-group
differences in terms of making efforts to eat more healthily
Note: ns – nonsignificant
0
1
2
3
4
5
6
7
8
9
10
11
12
13
TFEQ-R18:
Cognitive restraint
TFEQ-R18:
Emotional eating
TFEQ-R18:
Uncontrolled eating
ns
ns ns
ns
ns
ns
ns
ns
ns
Vegetarian diet Vegan diet Control group
Fig. 5 Means and standard error of the eating behaviours as measured
by the Three-Factor Eating Questionnaire-R18 (TFEQ-R18)
0
5
10
15
20
25
30
35
40
Vegan dietteidnairategeV
EHQ Knowledge
Ethic reason Health reason
p = .12
Fig. 6 Moderation effect of reasons for following specific diet
Table 3 Prediction models of orthorexia nervosa in individuals fol-
lowing a meat-free diet
β the standardized beta
*p < 0.05, **p < 0.01, ***p < 0.001
a Vegetarian and vegan diet
Variable β R2-change
Model 1: Problems associated with healthy eating
Cognitive restraint 0.411*** 0.193
Emotional eating − 0.062
Uncontrolled eating − 0.065
Type of dieta0.166
Duration of diet − 0.092
Body mass index − 0.222*
Model 2: Knowledge of healthy eating
Cognitive restraint 0.331** 0.150
Emotional eating − 0.099
Uncontrolled eating − 0.050
Type of dieta0.292**
Duration of diet 0.087
Body mass index − 0.167
Model 3: Feeling positively about healthy eating
Cognitive restraint 0.420*** 0.245
Emotional eating − 0.101
Uncontrolled eating 0.161
Type of dieta0.055
Duration of diet − 0.233*
Body mass index − 0.165
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449Eating and Weight Disorders - Studies on Anorexia, Bulimia and Obesity (2019) 24:441–452
1 3
over time, feeling in control when they eat healthily, feeling
a sense of satisfaction in eating the way they do and feeling
great when they eat healthily (items associated with feeling
positively about healthy eating). This would suggest that
individuals following a vegetarian and vegan diet presented
similar problems associated with healthy eating and similar
patterns of feeling positively about healthy eating. It may
also suggest that both groups have an interest in (or they are
preoccupied with) healthy eating comparing to individuals
following a meat diet. Our findings suggest that following a
special diet could prompt more focus on the quality of foods
consumed both in individuals following a vegetarian diet and
individuals following a vegan diet.
The conclusions of our paper are in line with the results
of the latest research [2], which have shown that vegetar-
ians and vegans do not differ in orthorexic eating behaviour,
but both groups presented higher level of orthorexic eating
behaviour than individuals with rare and frequent meat con-
sumption. Moreover, individuals showing restrained eating
behaviour mainly because of ethical reasons or with the aim
to lose weight, present more orthorexic eating behaviour
than those who do not limit their food intake. The authors
[2] argue that a vegan diet does not directly result in a disor-
dered eating behaviour, nevertheless, the prevalence of ON
in the vegan (7.9%) and vegetarian groups (3.8%) are higher
than in the individuals consuming meat (3.6% of participants
with rare meat consumption and 0% of participants with
frequent meat consumption). This could point to the fact
that vegetarian or vegan diet could increase the risk of ON
[2]. Unpublished research [in 2] has shown that in vegans,
ON is solely related to health-related motives, whereas ethi-
cal reasons are not, indicating that underlying motives and
beliefs might moderate this effect. Other studies [35] have
shown that individuals who follow a vegetarian diet (ash-
tanga practitioners) present more pathological symptoms of
strict health-oriented eating patterns (the prevalence rate for
orthorexia in this group was 43%), and they might push their
attention to it to potentially orthorexic limits.
Our results also demonstrated that individuals who focus
on excluding all animal products (meat, seafood, poultry,
eggs and dairy) from their daily diet showed a higher level of
knowledge of healthy eating than those who followed a veg-
etarian diet (Hypothesis2 was confirmed) and those who fol-
lowed an omnivore diet (Hypothesis1 was confirmed). They
are more informed than other individuals with differential
food preferences about healthy eating, and the way their food
is prepared is more important in their diet than in those fol-
lowing a vegetarian or omnivore diet. In their opinion, their
eating habits are superior, and their diet is better than other
individuals’ diets. They are also convinced that they prepare
food in the most healthy way. A vegan diet might become a
guise for disordered eating, including for orthorexia nervosa,
and might provide an excuse for following food rules that
result in the removal of whole food groups [36].
In the present study, we also aimed to analyse the impact
of ethical and health reasons for following a meat-free diet
on the relationship between vegan versus vegetarian diets
and eating behaviours. Participants maintaining a meat-
free diet for health reasons had more risk on the knowledge
subscale of EHQ, but this effect was significant only for
vegans (for vegetarians, there were no difference between
ethical and health reasons) (Hypothesis2 was confirmed).
Therefore, vegans were a group more likely to develop cog-
nitive orthorexic eating behaviours (knowledge subscale) if
they were on a meat-free diet for health reasons. So, ethical
causes might be a protective factor in the development of
orthorexic eating behaviours as a cognitive aspect in this
group.
The third objective of the present study was to identify the
predictors of cognitions, behaviours and feelings related to
orthorexia nervosa among individuals with differential food
preferences. Our research showed that cognitive restraint
was a predictor of orthorexia nervosa among a sample fol-
lowing a meat-free diet (vegetarian and vegan diet) (Hypoth-
esis3 was confirmed). Focusing on the control of food intake
might start out as a claim for healthy eating and advance into
increasingly restrictive dietary rules [36]. The consequences
of cognitive restraint (stable disposition to limit and control
food intake) could be following: dysregulation of internal
perceptions of hunger and satiety (which are essential for
homeostatic regulation), emotional dysregulation, low self-
esteem and low body satisfaction [37]. Martins etal. [38]
report that vegetarianism might be used as a mask for diet-
ing behaviour. The recent study has shown that individuals
with a special diet self-reported significantly more current
and past eating disorders compared to those following no
special diet [4].
It is worth pointing out that our study also showed that
besides cognitive restraint, (a) lower (reduced) body mass
index determines problems associated with healthy eating,
(b) following a vegan diet is a predictor of knowledge of
healthy eating, especially among those who follow a vegan
diet for health reasons and (c) shorter duration of following
a vegetarian and vegan diet predicts feeling positively about
healthy eating among individuals following a meat-free diet
(vegetarian and vegan diet). Therefore, there are reasons to
suspect that cognitions connected with an extreme focus on
healthy eating could be related to control weight or weight
loss, which was previously suggested in other studies [2,
3, 11]. Focusing on diet based on the complete exclusion
of all animal-based products results in adopting strategies
to substitute animal protein-dense foods with plant protein-
dense foods and plant-based food products (e.g., textured soy
products, almond, rice milk, uncooked cereals, seeds) along
with an increase in the consumption of meat substitute foods
Content courtesy of Springer Nature, terms of use apply. Rights reserved.

450 Eating and Weight Disorders - Studies on Anorexia, Bulimia and Obesity (2019) 24:441–452
1 3
[39]. The fact that vegans’ daily food intake is very selective
could explain their advanced knowledge of healthy eating.
In case of feelings linked to orthorexia nervosa, our findings
could suggest that early identification of following a vegetar-
ian and vegan diet may be an important factor in preventing
orthorexic behaviours. It could also indicate that restrictive
eating might be a regulator of emotional state—especially
insituations associated with high levels of anxiety and guilt
after eating high-caloric foods.
It is worth paying attention to other studies which indicate
behavioural and cognitive features associated with ON (e.g.,
weigh lost, less pathological body image discomfort) [10,
15] and its relationship with eating disorders (e.g., anorexia
nervosa, AFRID) [10, 40–42] as well as with other psycho-
pathological dimensions (e.g., obsessive–compulsive disor-
der, obsessive–compulsive personality disorder) [14, 40].
Study [18] on the brain–behaviour relationship has shown
that ON was independently related to executive function
deficit (cognitive rigidity, emotional control, self-monitoring
and working memory) which AN and OCD profiles already
overlap.
Several limitations in the present study should be
acknowledged. First, our sample size did not include a large
number of individuals who followed a special diet, which
may have reduced our ability to find significant differences
among special diet groups. Second, our sample cannot be
considered representative for all individuals following a veg-
etarian and vegan diet; it would be desirable to replicate and
extend the present findings in the future. Third, we evaluated
a posteriori the reason for following a meat-free diet, and the
number of individuals choosing ethical versus health reasons
was not equivalent. Fourth, we did not assess emotional dis-
tress related to food choices. Emotional distress might have
a significant impact on ON, as disordered eating behaviours
might be considered as emotional regulation strategy [43].
Consequently, this variable should be taken into account as
potential moderator of the link between specific dietary hab-
its and ON in the further research. However, it is important
to underline that linking participants distress to ON behav-
iour would require assessing those variables with ambula-
tory assessment (contrary to for example the reason for fol-
lowing the diet that changes over time less dynamically that
participants’ distress) and the present research by exploring
the link between type of diet, ON behaviour and potential
mediators (like reasons for following the diet) provides the
basis for further development of this kind of ambulatory
research. Forthcoming research should include also larger
sample sizes and simple random sampling across the gen-
eral population (among individuals indicating an omnivore
diet). Besides, the current results are based on self-reporting
that could be subject to potential bias. Moreover, the current
study was a cross-sectional one and could not assess the
causality of relationships. Future studies should determine
causal relationships between measured variables and poten-
tial mediators in ambulatory settings.
Despite the aforementioned limitations, our results could
contribute to identify potential risk factors for strict health-
oriented eating patterns and to gain a better insight into orth-
orexia nervosa. We suppose that following diet and lifestyle
recommendations for a well-balanced vegetarian diet (see
Fig.1) could be helpful for individuals with orthorexic eat-
ing behaviours to better plan both the quality and quantity
of their meals.
Further research is needed to investigate whether vegetar-
ianism and/or veganism serve as risk factors for developing
orthorexic eating behaviours. It is also worth examining veg-
etarianism and orthorexic eating behaviour longitudinally
to better understand how orthorexia nervosa symptoms and
vegetarianism may propel each other over time.
Expanding the knowledge about ON will contribute to
both public health and clinical research. In public health
research it might help in developing prevention programs
addressing orthorexic eating behaviour. In clinical research,
it contributes to assess a much needed therapeutic program
for the treatment of ON. The research providing a general
knowledge on ON and dietary behaviours enables also to
determinate more precisely crucial variables to measures or
manipulate in the further studies.
Funding This study was funded by the National Science Centre (NCN),
Poland (grant number 2017/01/X/HS6/00007).
Compliance with ethical standards
Conflict of interest The authors declare that they have no conflict of
interest.
Ethical approval The research was approved by the local ethics com-
mittee (SWPS University of Social Sciences and Humanities, Katowice
Faculty of Psychology; no. WKEB45/03/2017). All procedures per-
formed in this study were in accordance with the ethical standards of
the institutional and/or national research committee and with the 1964
Helsinki declaration and its later amendments or comparable ethical
standards.
Informed consent Informed consent was obtained from all individual
participants included in the study.
Open Access This article is distributed under the terms of the Crea-
tive Commons Attribution 4.0 International License (http://creat iveco
mmons .org/licen ses/by/4.0/), which permits unrestricted use, distribu-
tion, and reproduction in any medium, provided you give appropriate
credit to the original author(s) and the source, provide a link to the
Creative Commons license, and indicate if changes were made.
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