Skip to main content
NCBI home page
NIHPA Author Manuscripts logoLink to NIHPA Author Manuscripts
. Author manuscript; available in PMC: 2025 Nov 1.
Published in final edited form as: Int J Eat Disord. 2024 Sep 1;57(11):2156–2166. doi: 10.1002/eat.24281

Difficulties in emotion regulation in avoidant/restrictive food intake disorder

Casey M Stern 1,2, Haley Graver 1, Iman McPherson 3, Julia Gydus 3, P Evelyna Kambanis 1, Lauren Breithaupt 1,4,5, Helen Burton-Murray 1,4,6,7, Lázaro Zayas 1,4, Kamryn T Eddy 1,4, Jennifer J Thomas 1,4,*, Kendra R Becker 1,4,*
PMCID: PMC11569823  NIHMSID: NIHMS2015141  PMID: 39219064

Abstract

Objective:

Despite substantial research indicating difficulties with emotion regulation across eating disorder presentations, emotion regulation has yet to be studied in adults with avoidant/restrictive food intake disorder (ARFID). We hypothesized that (1) those with ARFID would report greater overall emotion regulation difficulties than non-clinical participants, and (2) those with ARFID would not differ from those with other eating disorders on level of emotion regulation difficulty.

Method:

One hundred thirty-seven adults (age 18–30) from an outpatient clinic with ARFID (n=27), with other primarily restrictive eating disorders (e.g., anorexia nervosa; n=34), and with binge/purge eating disorders (e.g., bulimia nervosa; n=51), as well as non-clinical participants (n=25) recruited via Amazon Mechanical Turk (Mturk), completed the Difficulties in Emotion Regulation Scale (DERS). We compared DERS scores across groups.

Results:

In line with expectations, patients with ARFID scored significantly higher than non-clinical participants on the DERS Total (p=.01) with a large effect size (d=.87). Also as hypothesized, those with ARFID did not differ from those with other primarily restrictive (p=.99) or binge/purge disorders (p=.29) on DERS Total.

Discussion:

Adults with ARFID appear to exhibit emotion regulation difficulties that are greater than non-clinical participants, and commensurate with other eating disorders. These findings highlight the possibility of emotion regulation difficulties as a maintenance mechanism for ARFID.

Keywords: avoidant/restrictive food intake disorder, emotion regulation, anorexia nervosa, bulimia nervosa, impulsivity, Difficulties in Emotion Regulation Scale, cognitive-behavioral model, treatment target, eating disorders, feeding and eating disorders

Introduction

Avoidant/restrictive food intake disorder (ARFID) is a feeding/eating disorder characterized by limited food intake in volume and/or variety. Contrary to other eating disorders in the Diagnostic and Statistical Manual of Mental Disorders – Fifth Edition (DSM-5; American Psychiatric Association, 2013), such as anorexia nervosa (AN), atypical AN, and bulimia nervosa (BN), restriction in ARFID is not motivated by body image disturbance. Instead, those with ARFID may identify sensory sensitivity (i.e., aversion to certain tastes and textures), fear of aversive consequences of eating or food (i.e., fear of vomiting, choking, or gastrointestinal distress), and/or lack of interest in eating or food as reasons for limited intake (Reilly et al., 2019; Thomas et al., 2017). Like other eating disorders, limited dietary amount and/or variety in ARFID results in low weight/impaired growth, malnourishment, medical consequences such as endocrine and gastrointestinal alterations, and/or significant psychosocial impairment (Aulinas et al., 2020; Kambanis et al., 2020). Previous research has identified potential cognitive-behavioral (Thomas et al., 2021, 2020) and neurobiological (Becker et al., 2021; Burton Murray, Becker et al., 2022; Thomas et al., 2017) risk and maintenance factors of ARFID. However, little is known about emotional functioning in individuals with ARFID, despite the well-documented relevance of emotional functioning in other eating disorders (e.g., Brockmeyer et al., 2014; Prefit et al., 2019).

The multidimensional model of emotion regulation conceptualizes emotion regulation as the process of responding adaptively to emotional distress (Gratz & Roemer, 2003; Lavender et al., 2017). A substantial body of literature has investigated emotion regulation in eating disorders, and deficits in emotion regulation have been identified in individuals with AN, BN, binge-eating disorder (BED), and other specified feeding or eating disorders (OSFED) compared to healthy controls (Brockmeyer et al., 2014; Dingemans et al., 2017; Prefit et al., 2019). As such, difficulties with emotion regulation are hypothesized to be key to the maintenance of these disorders (Haynos & Fruzzetti, 2011; Lavender et al., 2015; Leehr et al., 2015). Particular dimensions of emotion regulation such as awareness of emotions, understanding emotions, and acceptance of negative emotions (as opposed to having secondary negative emotions, e.g., becoming angry or upset about having the initial negative emotions) present as fairly consistent difficulties across the eating disorders spectrum, while other dimensions such as impulsivity may be specific to those with binge/purge behaviors (Brockmeyer et al., 2014; Dingemans et al., 2017; Prefit et al., 2019). Consequently, most eating disorder treatment models (e.g., Baer et al., 2005; Chen et al., 2008, 2015; Fairburn et al., 2003; Roos et al., 2021; Sala et al., 2023; Waller et al., 2019; Wisniewski et al., 2007; Wonderlich et al., 2015) include interventions aimed at targeting facets of emotion regulation.

Fear of gaining weight is a core symptom for AN, atypical AN, and BN that drives disordered eating behaviors (Fairburn et al., 2003); likewise, the cognitive-behavioral model of ARFID proposes that difficulty tolerating negative emotions like fear (e.g., of new foods, or choking) and disgust (by sensory properties of food) drive restriction of volume and/or variety of foods in those with ARFID. Current literature suggests that difficulties managing emotions are relevant across presentation types of ARFID. Fear that food will be unpalatable or cause negative consequences (e.g., gastrointestinal pain, vomiting, choking) is one pathway by which emotion dysregulation is theorized to motivate dietary restriction in variety and/or volume among those with ARFID. Disgust is also strongly implicated in the sensory sensitivity presentation of ARFID as a possible motivator for food neophobia and selectivity. Different roles of disgust and related emotions as a mechanism of ARFID symptoms have also been suggested (Breiner et al., 2023; Harris et al., 2019; Menzel et al., 2019), which all suggest difficulties with regulating negative mood states. Despite the theoretical relations between ARFID symptoms and emotional functioning, no studies have explored if and how emotion regulation difficulties may manifest in those with ARFID.

Currently, there are no empirically supported treatments for ARFID, presenting an immense barrier to effective care for this disorder. Though early evidence demonstrates the preliminary efficacy of CBT-AR for both youth and adults with ARFID (Thomas et al., 2021, 2020), the cognitive-behavioral model of ARFID itself has not been empirically tested. Given that current literature suggests that difficulties regulating emotions may drive ARFID symptoms across presentations, it is critical to determine whether those with ARFID exhibit the hypothesized emotion regulation difficulties. Therefore, this study aims to address a clear gap in the literature by testing whether adults with ARFID exhibit difficulties in emotion regulation compared to non-clinical participants. In addition, we aimed to compare emotion regulation in those with ARFID to those with other eating disorders on global and specific aspects of emotion regulation because effective intervention targets may be similar for other eating disorders if emotional functioning is similar. We hypothesized that (1) those with ARFID would report greater emotion regulation difficulties than non-clinical participants (both overall and on individual facets of emotion regulation), and (2) those with ARFID would not differ from those with other eating disorders on overall level and facets of emotion regulation difficulty.

Method

Participants

Clinical Participants

Table 1 provides demographic characteristics of the sample of 137 adults aged 18–30. Of the potential participants who were considered for inclusion in the final sample, around 10% had not completed a full DERS and therefore were excluded from our analytic sample. Patients with ARFID (n=27, Mage=23), patients with other eating disorders with primary restrictive eating (e.g., AN, atypical AN; n=34, Mage=24), and patients with eating disorders with primary binge eating and/or purging (e.g., BN, BED; n=51, Mage=25) from an outpatient eating disorder specialty clinic completed all study measures as part of their clinical intake; these were individuals who were unwell enough to refer themselves or be referred for outpatient treatment, but not so unwell as to warrant a more intensive level of care. Table 2 provides a diagnostic breakdown within each group. As more fully described in Becker et al. (2019), diagnoses were conferred during a routine clinical interview by each participant’s treating psychologist or psychiatrist, using a template derived from the DSM-5 criteria which included questions specifically reflective of an ARFID diagnosis (e.g., numbers of foods eaten regularly from each of the five major food groups, sensitivity to appearance, taste, and smell of foods, appetite and enjoyment of food, experiences of food-related trauma, and psychosocial impairment; American Psychiatric Association, 2022; Becker et al., 2019) in addition to questions reflective of the other eating disorders represented in our sample (e.g. shape and weight concerns, restrictive behaviors, binge-spectrum behaviors, purging behaviors).

Table 1.

Demographic characteristics of 137 adults with feeding and eating disorders and non-clinical participants.

ARFID (n=27) Restrict (n=34) Binge/purge (n=51) Non-clinical (n=25) Between-groups comparisons*
Female, N (%) 18 (67%) 31 (91%) 43 (84%) 16 (64%) .45 ≥ p < .001*
Age, M (SD) 23 (4.5) 24 (4.4) 25.7 (4.6) 28.2 (3.7) .82 ≥ p < .001*
Race, N (%) American Indian/ Alaska Native 0 (0%) 0 (0%) 0 (0%) 0 (0%) Omnibus
p = .248*
Asian 0 (0%) <5 (<15%) 7 (14%) <5 (<20%)
Black/African American <5 (<19%) 0 (0%) <5 (<10%) <5 (<20%)
Native Hawaiian/ Other Pacific Islander 0 (0%) 0 (0%) 0 (0%) 0 (0%)
White 24 (89%) 33 (97%) 43 (84%) 21 (84%)
More than one race <5 (<19%) 0 (0%) 0 (0%) <5 (<20%)
Ethnicity, N (%) Hispanic/Latinx <5 (<19%) <5 (<15%) <5 (<10%) <5 (<20%) Omnibus
p = .836
Not Hispanic/Latinx 24 (89%) 32 (94%) 47 (92%) 24 (96%)
BMI (kg/m2), M (SD) Absolute BMI for age >18 22.5 (5.3) 20.2 (3.1) 25.3 (6.9) 29.6 (7.8) .26 ≥ p < .001*
Open in a new tab
*

Note. ARFID = avoidant/restrictive food intake disorder; “Restrict” refers to the group with other (non-ARFID) eating disorders with primary restrictive eating; “Binge/purge” refers to the group with eating disorders with primary binge eating and/or purging; “Non-clinical” refers to the non-clinical participant group.

To protect the privacy of participants, subgroups of fewer than 5 people are not shown as exact numbers (and total counts therefore do not add up to 100%).

*

ANOVA for age and BMI; Fisher’s Exact Test for sex, race, and ethnicity

*

Post hoc comparisons revealed that the Restrict group and the Binge/purge group, but not the ARFID group, significantly differed from non-clinical participants in terms sex breakdown

*

Post hoc comparisons revealed that non-clinical participants differed from the ARFID group and from the Restrict group in terms of age. We controlled for age in all analyses.

*

Post hoc comparisons revealed that the Restrict group differed from the Binge/purge group and from non-clinical participants, but not from the ARFID group, in terms of BMI.

*

Because of small cell count for certain racial categories, we compared across groups by combining all categories except “White” for analysis purposes

Table 2.

Breakdown of diagnoses within the two groups with other eating disorders, and presentations within the group with avoidant/restrictive food intake disorder (ARFID).

ARFID (n = 27)* Other restricting (n = 34) Binge/purge (n = 51)
ARFID sensory sensitivity presentation 20 - -
ARFID fear of aversive consequences presentation 9 - -
ARFID lack of interest in eating or food presentation 14 - -
Anorexia nervosa, restricting subtype - 18
OSFED, atypical anorexia nervosa - 16
Anorexia nervosa, binge-purge subtype - 6
Bulimia nervosa - 25
Binge-eating disorder - 12
OSFED, purging disorder - 1
OSFED, subthreshold bulimia nervosa - 2
OSFED, subthreshold binge-eating disorder - 5
Open in a new tab
*

Note: ARFID = avoidant/restrictive food intake disorder; “Other restricting” refers to the group with other (non-ARFID) eating disorders with primary restrictive eating; “Binge/purge” refers to the group with eating disorders with primary binge eating and/or purging

*

OSFED = other specified feeding or eating disorder

*

The sum of all three ARFID presentations will be greater than the number of people in the ARFID group (n=27) as many individuals had more than one co-occurring presentation

For participants with ARFID, clinicians (clinical psychologists, psychiatrists, and predoctoral interns and advanced practicum students supervised by licensed clinical psychologists/psychiatrists) determined which of the three presentations (sensory sensitivity, fear of aversive consequences, and/or lack of interest in eating or food) were present (Burton Murray et al., 2021). Clinicians could select more than one presentation for each patient if appropriate, given that ARFID presentations can and often do co-occur (Reilly et al., 2019; Thomas et al., 2017). Based on unstructured clinical interviews, 20 participants (74%) were identified as having sensory sensitivity, nine participants (33%) were identified as having fear of aversive consequences, and 14 participants (52%) were identified as having lack of interest in eating or food (these numbers add up to more than 27 or 100% of participants because 13 participants had more than one presentation). All participants consented to their de-identified responses being stored in a clinical data repository. Clinic participants received no compensation as they completed the measures as part of routine clinical care, in a battery of intake questionnaires prior to their clinical evaluation.

Non-Clinical Participants

We also recruited non-clinical participants aged 18–30 (n=25, Mage=28) via Amazon Mechanical Turk (MTurk). We have outlined screening procedures for non-clinical participants below. To ensure data quality for individuals recruited through MTurk, survey settings prevented individuals from participating twice. Additionally, and in line with recommendations for analyzing MTurk data (Kambanis et al., 2021), we collected MTurk worker IDs to avoid duplicate entries. To ensure the absence of “bots” (non-human workers) in our dataset, we also embedded brief validity checks in each measure (a practice which has been supported by Kung et al., 2018), later removing any MTurk participants who failed these validity checks (Kambanis et al., 2021). Data from this sample were also used in Stern et al., 2024; however, responses on the Difficulties in Emotion Regulation Scale (DERS; the focus of the current study) were not reported in that study. Non-clinical participants received $15 for completing a battery of questionnaires.

Measures

Full-Sample Measures

Demographics.

All participants reported their age, sex assigned at birth, race, and ethnicity on a standard self-report form.

Difficulties in Emotion Regulation Scale.

All participants completed the DERS (Gratz & Roemer, 2003), a 36-item self-report measure of emotion regulation difficulties. In addition to the total score, Gratz & Roemer (2004) validated six subscales representing six different dimensions of emotion regulation difficulty captured in the measure: Nonacceptance of Emotional Responses (“Nonacceptance” subscale), reflecting tendency to have secondary negative emotions towards one’s own emotions (e.g., “When I’m upset, I feel guilty for feeling that way”); Difficulties Engaging in Goal-Directed Behavior (“Goals” subscale), reflecting difficulty attending to tasks at hand when experiencing negative emotions (e.g., “When I’m upset, I have difficulty getting work done”); Impulse Control Difficulties (“Impulse” subscale), reflecting difficulty controlling one’s own behavior when experiencing negative emotions (e.g., “When I’m upset, I lose control over my behaviors”); Lack of Emotional Awareness (“Awareness” subscale), reflecting difficulty being aware of one’s own emotions (e.g., “I pay attention to how I feel” [reverse-scored]); Limited Access to Emotion Regulation Strategies (“Strategies” subscale), reflecting tendency to believe that one cannot regulate oneself when experiencing negative emotions (e.g., “When I’m upset, I believe there is nothing I can do to make myself feel better”); and Lack of Emotional Clarity (“Clarity” subscale), reflecting difficulty understanding one’s own emotions (e.g., “I have difficulty making sense out of my feelings”). Participants rated their agreement with 36 questions pertaining to their own experiences with emotion regulation difficulties on a scale from 1 (Almost never, 0–10%) to 5 (Almost always, 91–100%). As such, higher DERS Total and subscale scores indicate a greater degree of regulation difficulty (for example, the “Awareness” subscale refers to lack of emotional awareness, or degree of difficulty with emotional awareness). Internal consistency in our sample was good to excellent (Cronbach’s α for the DERS Total = 0.95; α for Nonacceptance = 0.94; α for Goals = 0.91; α for Impulse = 0.90; α for Awareness = 0.87; α for Strategies = 0.93; α for Clarity = 0.87).

MTurk Screening Measures

We used the following measures to screen out eating disorders and clinically significant anxiety and depression psychopathology in our non-clinical participant sample:

Eating Disorder Examination - Questionnaire (Fairburn & Beglin, 2008).

The Eating Disorder Examination – Questionnaire (EDE-Q) is a measure of eating disorder attitudes and behaviors. Participants were classified as non-clinical if they scored below a clinical cut point of 2.3 (Mond et al., 2004) on the EDE-Q.

Nine-Item ARFID Scale (Burton Murray, Dreier et al., 2021; Zickgraf & Ellis, 2018).

The Nine-Item ARFID Scale (NIAS) is a brief measure of ARFID psychopathology. Participants were classified as non-clinical if their scores on the Picky Eating, Appetite, and Fear subscales fell below 10, 9, and 10, respectively, as these cut-offs suggest clinical levels of impairment (Burton Murray, Dreier et al., 2021; Zickgraf & Ellis, 2018). Those with eating disorders in our sample did not complete the NIAS, because it had not yet been introduced into the battery of intake measures completed by patients in the clinic at the time of data collection for most of those participants.

State-Trait Anxiety Inventory - Trait Scale (Spielberger et al., 1983).

The State-Trait Anxiety Inventory (STAI) Trait Scale is a measure of trait anxiety. Per guidance from Spielberger et al. (1983), participants were classified as non-clinical if their total score on the STAI – Trait Scale was below 44.

Center for Epidemiological Studies Depression Scale (Radloff, 1977).

The Center for Epidemiological Studies Depression Scale (CES-D) is a measure of depression psychopathology. Per guidance from Radloff (1977), participants were classified as non-clinical if their total score on the CES-D was below 16.

Data analysis

We compared group means for the DERS Total score across the four diagnostic groups (ARFID, primary restriction, primary binge/purge, and non-clinical participants) using an omnibus analysis of covariance (ANCOVA). We determined recruitment targets based on statistical guidance (VanVoorhis & Morgan, 2007; Kraemer & Thiemann, 1987) indicating that between 14 – 30 participants per cell would be sufficient to achieve 80% power to detect a medium-size effect at p < .05. We entered age as a covariate to account for differences in age between the groups (p < .001; see Table 1), given evidence that age is related to emotion regulation difficulties (Giromini et al., 2017). We also conducted multivariate analysis of covariance (MANCOVA) with diagnostic group entered as the independent variable and mean scores for each DERS subscale entered as dependent variables. We performed Tukey’s HSD test to conduct all planned post-hoc comparisons (for both ANCOVA and MANCOVA) between diagnostic groups. Significance level was set at 0.05.

To test the hypothesis (1) that ARFID would exhibit greater emotion regulation difficulties than non-clinical participants on both overall level and individual facets of difficulty, first we compared group means on the DERS Total score with the ANCOVA outlined above; then we compared group means on the DERS subscale scores using the MANCOVA outlined above. Following both the ANCOVA and MANCOVA, we performed Tukey’s HSD test to conduct post-hoc comparisons between those with ARFID and non-clinical participants.

To test the hypothesis (2) that those with ARFID would not differ from those with other eating disorders on overall level and facets of emotion regulation difficulty, first we compared group means for the DERS Total score using the ANCOVA outlined above; then we compared group means for the DERS subscale scores using the MANCOVA outlined above. Following both the ANCOVA and MANCOVA, we performed Tukey’s HSD test to conduct planned post-hoc comparisons between those with ARFID and those with other eating disorders. We chose to compare ARFID to other primary restrictive eating disorders (e.g., AN-restricting subtype [AN-R]; atypical AN) and disorders with binge/purge behaviors (e.g., BN, AN-BP, BED) because binge eating and purging have been shown to exhibit a high degree of emotion regulation difficulties, such as increased impulsivity, that are unique from restriction (Brockmeyer et al., 2014; Dingemans et al., 2017; Prefit et al., 2019). By comparing across presentations of eating pathology, we hoped to establish a clinical context for emotion regulation in those with ARFID, so as to be able to compare those with ARFID to those other eating disorders.

We conducted all analyses in R (R Core Team, 2022). Packages used for analyses included: dplyr (Wickham, H., François, R., Henry, L., Müller, K., Vaughan, D., 2023); psych (Revelle, 2022); corrplot (Wei & Simko, 2021); tidyverse (Wickham et al., 2019); ggplot2 (Wickham, 2016); agricolae (de Mendiburu, 2020), and emmeans (Lenth et al., 2023).

Results

ARFID Compared to Non-Clinical Participants

DERS Total in ARFID compared to Non-Clinical Participants.

A summary of these results is presented in Figure 1. A summary of age-adjusted estimated marginal group means is presented in Table 3. In support of our hypothesis that those with ARFID would report greater overall emotion regulation difficulties than non-clinical participants, the group with ARFID scored significantly higher than non-clinical participants on the DERS Total score (p = .012, d = 0.87 [large effect]).

Figure 1.

Figure 1.

Open in a new tab

Bar graph of age-adjusted estimated marginal group means and between-group analysis of covariance (ANCOVA) with planned pairwise comparisons for the Difficulties in Emotion Regulation Scale (DERS) Total score

Note. Error bars represent SEM. ARFID = avoidant/restrictive food intake disorder (n = 27); Restrict = other eating disorders with primary restriction (n = 34); Binge/purge = eating disorders with primary binge eating and/or purging (n = 51); Non-clinical = non-clinical participants (n = 25).

Italicized letters (a or b) indicate significant between-group differences.

Those with eating disorders in our sample did not complete the Nine Item ARFID Screen, because it had not yet been introduced into the battery of intake measures completed by patients in the clinic at the time of data collection for most of those participants.

Table 3.

Summary of age-adjusted estimated marginal group means for the Difficulties in Emotion Regulation Scale (DERS) Total and subscale scores.

ARFID (n=27) Restrict (n=34) Binge/purge (n=51) Non-clinical (n=25) F p
DERS Total, M (SEM) 92.70 (5.41) a 90.50 (4.75) a 104.6 (3.85) a 67.5 (5.72) b 7.61 <.001
Nonacceptance, M (SEM) 16.40 (1.20) ac 13.8 (1.14) ab 17.30 (0.93) ac 10.00 (1.38) b 5.50 <.001
Goals, M (SEM) 16.24 (1.04) ac 13.92 (0.92) ab 17.78 (0.74) c 9.88 (1.10) d 10.40 <.001
Impulse, M (SEM) 11.40 (1.14) ab 11.20 (1.00) ab 16.20 (0.81) ac 10.80 (1.20) ab 6.15 <.001
Awareness, M (SEM) 16.20 (1.14) ab 19.60 (1.00) a 16.50 (0.81) ab 13.50 (1.20) b 3.77 .006
Strategies, M (SEM) 20.00 (1.64) ab 17.70 (1.44) ab 23.50 (1.17) ac 15.10 (1.73) ab 5.47 <.001
Clarity, M (SEM) 12.47 (0.96) ac 14.38 (0.84) ab 13.21 (0.68) ac 8.11 (1.01) d 6.16 <.001
Open in a new tab

Note: ARFID = avoidant/restrictive food intake disorder; Restrict = other eating disorders with primary restriction; Binge/purge = eating disorders with primary binge eating and/or purging; Non-clinical = non-clinical participants; Nonacceptance = Nonacceptance of Emotional Responses DERS subscale, Goals = Difficulties Engaging in Goal-Directed Behavior DERS subscale; Impulse = Impulse Control Difficulties DERS subscale; Awareness = Lack of Emotional Awareness DERS subscale; Strategies = Limited Access to Emotion Regulation Strategies DERS subscale; Clarity = Lack of Emotional Clarity DERS subscale. Italicized letters (a, b, c, or d) indicate significant between-group differences.

DERS Subscales in ARFID Compared to Non-Clinical Participants.

As hypothesized, the group with ARFID scored significantly higher than non-clinical participants on the Nonacceptance (p = .008, d = 0.83 [large]), Goals (p < .001, d = 1.29 [large]), and Clarity (p = .015, d = 0.88 [large]) subscales of the DERS. There were no significant differences between those with ARFID and non-clinical participants on the Impulse (p = .984, d = .14 [negligible]), Awareness (p = .396, d = .42 [small]), or Strategies (p = .203, d = .66 [medium]) subscales, though the mean scores for those with ARFID were higher than the mean scores for non-clinical participants in all three cases.

ARFID Compared to other Eating Disorders

A summary of these results is presented in Figures 1 and 2. A summary of age-adjusted estimated marginal group means is presented in Table 3.

Figure 2.

Figure 2.

Open in a new tab

Bar graphs of age-adjusted estimated marginal group means and between-group analysis of covariance (ANCOVA) with age as a covariate and with planned pairwise comparisons for the Difficulties in Emotion Regulation Scale (DERS) subscale scores

Note. Error bars represent SEM. ARFID = avoidant/restrictive food intake disorder (n = 27); Restrict = other eating disorders with primary restriction (n = 34); Binge/purge = eating disorders with primary binge eating and/or purging (n = 51); Non-clinical = non-clinical participants (n = 25). Italicized letters (a, b, c, or d) indicate significant between-group differences.

DERS Total in ARFID Compared to Other Eating Disorders.

In line with expectations, those with ARFID did not differ from those with other primarily restrictive eating disorders (p = .990, d = .08 [negligible]) or from those with primary binge/purge eating disorders (p = .288, d = .39 [small]) on the DERS Total score.

DERS Subscales in ARFID Compared to Those with Other Eating Disorders.

There were no significant differences between those with ARFID and those with other restrictive eating disorders on any of the DERS subscales (Nonacceptance p = .429, d = .37 [small]; Goals p = .329, d = .43 [small]; Impulse p = .998, d = .05 [negligible]; Awareness p = .117, d = .64 [medium]; Clarity p = .428, d = .40 [small]; and Strategies p = .723, d = .27 [small]). The group with ARFID scored significantly lower than the group with primary binge/purge eating disorders on the Impulse subscale (p = .005, d = −0.78 [medium]). There were no significant differences between those with ARFID and those with binge/purge eating disorders on the Nonacceptance (p = .926, d = .16 [negligible]), Goals (p = .630, d = .27 [small]), Awareness (p = .997, d = .09 [negligible]), Clarity (p = .924, d = .19 [negligible]), or Strategies (p = .302, d = .35 [small]) subscales.

Discussion

This study provided the first empirical exploration of emotion regulation difficulties in adults with ARFID. In line with our hypotheses, we found that those with ARFID exhibited significantly greater difficulties in emotion regulation compared to non-clinical participants. Further, the severity of emotion regulation difficulties in ARFID did not differ from those with other restrictive eating disorders (i.e., AN, atypical AN), and were lower than those with binge/purge eating disorders (e.g., BN, BED) only regarding impulse control. The cognitive-behavioral model of ARFID posits that (intolerance of) negative emotions related to eating/food situations specifically are integral to the self-sustaining cycle of food avoidance that maintains ARFID symptoms (Thomas & Eddy, 2019). Building on this theoretical framework, we found that individuals with ARFID experience emotion regulation difficulties in general, and not just in relation to food or eating. Further, our results replicate and extend prior findings indicating that those with eating disorders across the diagnostic spectrum exhibit significantly greater difficulties in emotion regulation compared to non-clinical participants (e.g., Brockmeyer et al., 2014; Prefit et al., 2019).

Our findings also suggest that individuals with ARFID experience greater difficulty with specific dimensions of emotion regulation (i.e., nonacceptance of emotional responses, engaging in goal-directed behavior while experiencing negative emotions, and clarity into their own emotions), compared to healthy individuals. While the DERS was not designed to specifically measure emotion regulation difficulties with respect to eating and food situations, clinical observation suggests that emotion regulation difficulties related to food and eating may be present in individuals with ARFID. For example, those with ARFID may feel upset or embarrassed by their relationship with food or wish they could simply overcome their symptoms (Thomas et al., 2021). That emotional event might map onto the “nonacceptance of emotional responses” dimension of emotion regulation difficulties. Additionally, those with ARFID scored higher than non-clinical participants on the Goals subscale, demonstrating greater difficulty in engaging in goal-directed behavior when experiencing negative emotions. General difficulty in engaging in behavior consistent with goals may manifest in ARFID as food refusal/restriction due to intense disgust/fear, even when increases in dietary volume and/or variety are needed for improved psychological and physical health (Thomas et al., 2021; Thomas & Eddy, 2019). Our data also suggest that those with ARFID show more difficulty understanding their own emotions compared to healthy individuals. This is consistent with research indicating that those with other restrictive eating disorders have more difficulty with emotional clarity than non-clinical participants (Brockmeyer et al., 2014; Lavender et al., 2015; Prefit et al., 2019), as well as clinical observation of individuals with ARFID tending to minimize their symptoms.

Those with ARFID endorsed similar levels of emotion regulation difficulty, both overall and in most specific dimensions of difficulty, compared to those with other primary restrictive eating disorders (AN-R and atypical AN). These findings suggest that those with ARFID may exhibit some similarities to those with other restrictive eating disorders, despite the difference in motivation for restriction. These findings also align with existing literature indicating that many dimensions of emotion regulation difficulty do not vary notably by eating disorder type (Brockmeyer et al., 2014; Prefit et al., 2019).

Participants with ARFID also endorsed similar levels of emotion regulation difficulty, both overall and regarding most specific dimensions of difficulty, compared to those with primary binge eating and/or purging eating disorders. The only exception was that those with ARFID scored significantly lower on problems with impulse control than those with binge/purge eating disorders. This finding supports and extends prior conceptualizations of restrictive eating disorders (i.e., previously AN, and now also ARFID) being characterized by emotional and behavioral avoidance, versus binge eating and purging being characterized by rash action when experiencing intolerable emotions (Brockmeyer et al., 2014; Lavender et al., 2015). Thus, future research is needed to clarify the potentially nuanced relationship between ARFID and impulsivity.

Limitations and Future Directions

Our findings must be interpreted in light of limitations. First, while the overall sample was moderate in size, the small number of participants with each ARFID presentation prevented us from exploring the potential relationship between ARFID presentation and emotion regulation difficulties. Second, most of our sample was white and non-Hispanic, limiting the generalizability of these findings to other demographic groups. Further, our sample included treatment-seeking individuals at the outpatient level of care only, potentially limiting generalizability to those in higher levels of care/higher acuity; additionally, results may differ from non treatment-seeking individuals, who represent a large proportion of those with eating disorders (Hart et al., 2011). Replication with larger samples and different recruitment sources is needed. Moreover, given the transdiagnostic nature of emotion regulation difficulties, findings may be due to other psychopathology (e.g., anxiety, depression) that is commonly comorbid with ARFID (Kambanis, Harshman et al., 2022; Kambanis, Rozzell-Voss et al., 2023). While data on potential history of ARFID was not available for those with non-ARFID eating disorders in our sample, it has been demonstrated that ARFID to non-ARFID eating disorder diagnostic crossover does occur (Kambanis, Mancuso et al., 2024; Kambanis, Tabri et al., 2024) and thus future research should investigate any potential impact of past history of ARFID on emotion regulation. Data on comorbid psychopathology were also not available for the clinical samples, nor were we able to assess for history of psychopathology in the MTurk sample. Finally, future research should also investigate emotion regulation in children with ARFID. Important strengths to highlight include that this is the first exploration of emotion regulation difficulties in adults with ARFID, and we were able to recruit a range of treatment-seeking individuals with ARFID that is consistent with patient presentations to eating disorder clinics. Further strengths include that all diagnoses were conferred directly by (or under the supervision of) PhD- or MD-level clinicians with expertise in eating disorders (particularly ARFID) using a DSM-5 derived clinical evaluation template (Becker et al., 2019). Findings warrant further investigation of emotion regulation as a maintenance factor in the persistence of ARFID as suggested by the cognitive-behavioral model of ARFID. Investigation of emotion regulation difficulties uniquely in the context of eating and food situations would be a compelling avenue for future research (e.g., using ecological momentary assessment to examine emotion regulation difficulties before and after eating).

Conclusion

The current study provides preliminary evidence that individuals with ARFID experience emotion regulation difficulty compared to healthy individuals, and similar difficulties compared to those with other primarily restrictive eating disorders. These findings highlight the possibility that emotion regulation difficulties may be a symptom maintenance mechanism for ARFID. Future research is needed to clarify and further explore temporal relationships between emotional functioning and ARFID symptoms.

Public Significance Statement.

Avoidant/restrictive food intake disorder (ARFID) is an eating disorder with serious health consequences, such as endocrine and gastrointestinal problems, and psychological distress. There are currently no empirically supported treatments for ARFID. The cognitive-behavioral formulation on which at least one proposed ARFID treatment is based underscores emotion regulation difficulties (i.e., negative thoughts and feelings) in ARFID. Understanding emotional functioning in those with ARFID may be valuable for further treatment development.

Acknowledgments: Not Applicable.

Funding: Research reported in this publication was supported by the National Institutes of Health: National Institute of Mental Health KL2TR002542 (LB), K23MH125143 (KRB), K24MH135189 (JJT), K23DK131334 (HBM). The content is solely the responsibility of the authors and does not necessarily represent the official views of the funding agencies.

Availability of Data and Materials: The data that support the findings of this study are available from the corresponding author upon request.

Footnotes

Author Contributions [pick from the list below]:

CMS: Investigation, Methodology, Data curation, Formal analysis, Visualization, Writing - original draft, Writing - review & editing. HG: Data Curation, Formal Analysis, Visualization, Writing - Original Draft, Writing - Review & Editing. IM: Writing - Review & Editing. JG: Writing - Review & Editing. PEK: Data curation, Writing - review & editing. LB: Data curation, Writing - review & editing. HBM: Data curation, Writing - review & editing. LZ: Data curation, Writing - review & editing. KTE: Data curation, Writing - review & editing. JJT: Supervision, Methodology, Data curation, Writing - review & editing. KRB: Supervision, Conceptualization, Methodology, Data curation, Formal analysis, Writing - original draft, Writing - review & editing.

Declarations

Ethics Approval and Consent to Participate: The study was conducted according to the Declaration of Helsinki and study protocol was approved by the Institutional Review Board (Protocol 2013P002614). Written informed consent was obtained from all participants.

Competing Interests: Drs. Becker, Eddy, and Thomas receive royalties from Cambridge University Press for the sale of their books on ARFID. Dr. Breithaupt is a consultant for Otsuka Pharmaceuticals. Drs. Burton-Murray and Thomas receives royalties for book sales from Oxford University Press for book on rumination syndrome. Drs. Thomas and Eddy receive consulting fees from Equip Health.

Consent for Publication: The authors consent for this manuscript to be published. There are no other parties involved in the decision to publish.

References

  1. American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th Edition). [Google Scholar]
  2. American Psychiatric Association. (2022). Diagnostic and Statistical Manual of Mental Disorders (5th Edition: Text Revision). [Google Scholar]
  3. Aulinas A, Marengi DA, Galbiati F, Asanza E, Slattery M, Mancuso CJ, Wons O, Micali N, Bern E, Eddy KT, Thomas JJ, Misra M, & Lawson EA (2020). Medical comorbidities and endocrine dysfunction in low-weight females with avoidant/restrictive food intake disorder compared to anorexia nervosa and healthy controls. The International Journal of Eating Disorders, 53(4), 631–636. 10.1002/eat.23261 [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Baer RA, Fischer S, & Huss DB (2005). Mindfulness and acceptance in the treatment of disordered eating. Journal of Rational-Emotive and Cognitive-Behavior Therapy: RET, 23(4), 281–300. 10.1007/s10942-005-0015-9 [DOI] [Google Scholar]
  5. Becker KR, Keshishian AC, Liebman RE, Coniglio KA, Wang SB, Franko DL, Eddy KT, & Thomas JJ (2019). Impact of expanded diagnostic criteria for avoidant/restrictive food intake disorder on clinical comparisons with anorexia nervosa. The International Journal of Eating Disorders, 52(3), 230–238. 10.1002/eat.22988 [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Becker KR, Mancuso C, Dreier MJ, Asanza E, Breithaupt L, Slattery M, Plessow F, Micali N, Thomas JJ, Eddy KT, Misra M, & Lawson EA (2021). Ghrelin and PYY in low-weight females with avoidant/restrictive food intake disorder compared to anorexia nervosa and healthy controls. Psychoneuroendocrinology, 129, 105243. 10.1016/j.psyneuen.2021.105243 [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Breiner CE, Miller ML, Hamilton AL, Cruz Garcia S, Sanzari CM, & Hormes JM (2023). Exploring the relationship between food disgust and avoidant/restrictive food intake disorder (ARFID) presentations in a non-clinical collegiate sample. The International Journal of Eating Disorders, 56(7), 1444–1448. 10.1002/eat.23955 [DOI] [PubMed] [Google Scholar]
  8. Brockmeyer T, Skunde M, Wu M, Bresslein E, Rudofsky G, Herzog W, & Friederich H-C (2014). Difficulties in emotion regulation across the spectrum of eating disorders. Comprehensive Psychiatry, 55(3), 565–571. 10.1016/j.comppsych.2013.12.001 [DOI] [PubMed] [Google Scholar]
  9. Burton Murray H, Becker KR, Harshman S, Breithaupt L, Kuhnle M, Dreier MJ, Hauser K, Freizinger M, Eddy KT, Misra M, Kuo B, Micali N, Thomas JJ, & Lawson EA (2022). Elevated fasting satiety-promoting cholecystokinin (CCK) in avoidant/restrictive food intake disorder compared to healthy controls. The Journal of Clinical Psychiatry, 83(5), 41767. 10.4088/JCP.21m14111 [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Burton Murray H, Dreier MJ, Zickgraf HF, Becker KR, Breithaupt L, Eddy KT, & Thomas JJ (2021). Validation of the nine item ARFID screen (NIAS) subscales for distinguishing ARFID presentations and screening for ARFID. The International Journal of Eating Disorders, 54(10), 1782–1792. 10.1002/eat.23520 [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Chen EY, Matthews L, Allen C, Kuo JR, & Linehan MM (2008). Dialectical behavior therapy for clients with binge-eating disorder or bulimia nervosa and borderline personality disorder. The International Journal of Eating Disorders, 41(6), 505–512. 10.1002/eat.20522 [DOI] [PubMed] [Google Scholar]
  12. Chen EY, Segal K, Weissman J, Zeffiro TA, Gallop R, Linehan MM, Bohus M, & Lynch TR (2015). Adapting dialectical behavior therapy for outpatient adult anorexia nervosa--a pilot study. The International Journal of Eating Disorders, 48(1), 123–132. 10.1002/eat.22360 [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. de Mendiburu F (2020). agricolae: Statistical Procedures for Agricultural Research (1.4.0) [Computer software]. https://cran.r-project.org/package=agricolae
  14. Dingemans A, Danner U, & Parks M (2017). Emotion Regulation in Binge Eating Disorder: A Review. Nutrients, 9(11). 10.3390/nu9111274 [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Dolan SC, Kambanis PE, Stern CM, Becker KR, Breithaupt L, Gydus J, Smith S, Misra M, Micali N, Lawson EA, Eddy KT, & Thomas JJ (2023). Anticipatory and consummatory pleasure in avoidant/restrictive food intake disorder. Journal of Eating Disorders, 11(1), 198. 10.1186/s40337-023-00921-w [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Fairburn CG, Cooper Z, & Shafran R (2003). Cognitive behaviour therapy for eating disorders: a “transdiagnostic” theory and treatment. Behaviour Research and Therapy, 41(5), 509–528. 10.1016/S0005-7967(02)00088-8 [DOI] [PubMed] [Google Scholar]
  17. Fairburn CG, & Beglin SJ (2008). Eating disorder examination questionnaire. In Cognitive behavior therapy and eating disorders (p. 309:313). [Google Scholar]
  18. Giromini L, Ales F, de Campora G, Zennaro A, & Pignolo C (2017). Developing age and gender adjusted normative reference values for the difficulties in emotion regulation scale (DERS). Journal of Psychopathology and Behavioral Assessment, 39(4), 705–714. 10.1007/s10862-017-9611-0 [DOI] [Google Scholar]
  19. Gratz KL, & Roemer L (2003). Multidimensional Assessment of Emotion Regulation and Dysregulation: Development, Factor Structure, and Initial Validation of the Difficulties in Emotion Regulation Scale1. Journal of Psychopathology and Behavioral Assessment. [Google Scholar]
  20. Harris AA, Romer AL, Hanna EK, Keeling LA, LaBar KS, Sinnott-Armstrong W, Strauman TJ, Wagner HR, Marcus MD, & Zucker NL (2019). The central role of disgust in disorders of food avoidance. The International Journal of Eating Disorders, 52(5), 543–553. 10.1002/eat.23047 [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Hart LM, Granillo MT, Jorm AF, & Paxton SJ (2011). Unmet need for treatment in the eating disorders: a systematic review of eating disorder specific treatment seeking among community cases. Clinical psychology review, 31(5), 727–735. [DOI] [PubMed] [Google Scholar]
  22. Haynos AF, & Fruzzetti AE (2011). Anorexia nervosa as a disorder of emotion dysregulation: Evidence and treatment implications. Clinical Psychology: A Publication of the Division of Clinical Psychology of the American Psychological Association, 18(3), 183–202. 10.1111/j.1468-2850.2011.01250.x [DOI] [Google Scholar]
  23. Kambanis PE, Bottera AR, & De Young KP (2021). Eating disorder prevalence among Amazon MTurk workers assessed using a rigorous online, self-report anthropometric assessment. Eating Behaviors, 41, 101481. 10.1016/j.eatbeh.2021.101481 [DOI] [PubMed] [Google Scholar]
  24. Kambanis PE, Kuhnle MC, Wons OB, Jo JH, Keshishian AC, Hauser K, Becker KR, Franko DL, Misra M, Micali N, Lawson EA, Eddy KT, & Thomas JJ (2020). Prevalence and correlates of psychiatric comorbidities in children and adolescents with full and subthreshold avoidant/restrictive food intake disorder. The International Journal of Eating Disorders, 53(2), 256–265. 10.1002/eat.23191 [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Kung FYH, Kwok N, & Brown DJ (2018). Are attention check questions a threat to scale validity? Applied Psychology = Psychologie Appliquee, 67(2), 264–283. 10.1111/apps.12108 [DOI] [Google Scholar]
  26. Lavender JM, Tull MT, DiLillo D, Messman-Moore T, & Gratz KL (2017). Development and Validation of a State-Based Measure of Emotion Dysregulation: The State Difficulties in Emotion Regulation Scale (S-DERS). Assessment, 24(2), 197–209. 10.1177/1073191115601218 [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Lavender JM, Wonderlich SA, Engel SG, Gordon KH, Kaye WH, & Mitchell JE (2015). Dimensions of emotion dysregulation in anorexia nervosa and bulimia nervosa: A conceptual review of the empirical literature. Clinical Psychology Review, 40, 111–122. 10.1016/j.cpr.2015.05.010 [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Leehr EJ, Krohmer K, Schag K, Dresler T, Zipfel S, & Giel KE (2015). Emotion regulation model in binge eating disorder and obesity--a systematic review. Neuroscience and Biobehavioral Reviews, 49, 125–134. 10.1016/j.neubiorev.2014.12.008 [DOI] [PubMed] [Google Scholar]
  29. Lenth RV, Bolker B, Buerkner P, Giné-Vázquez I, Herve M, Jung M, Love J, Miguez F, Riebl H, & Singmann H (2023, August 17). Estimated marginal means, aka least-squares means [R package emmeans version 1.8.8]. Comprehensive R Archive Network (CRAN). https://CRAN.R-project.org/package=emmeans [Google Scholar]
  30. Menzel JE, Reilly EE, Luo TJ, & Kaye WH (2019). Conceptualizing the role of disgust in avoidant/restrictive food intake disorder: Implications for the etiology and treatment of selective eating. The International Journal of Eating Disorders, 52(4), 462–465. 10.1002/eat.23006 [DOI] [PubMed] [Google Scholar]
  31. Mond JM, Hay PJ, Rodgers B, Owen C, & Beumont PJV (2004). Validity of the Eating Disorder Examination Questionnaire (EDE-Q) in screening for eating disorders in community samples. Behaviour Research and Therapy, 42(5), 551–567. 10.1016/S0005-7967(03)00161-X [DOI] [PubMed] [Google Scholar]
  32. Prefit A-B, Cândea DM, & Szentagotai-Tătar A (2019). Emotion regulation across eating pathology: A meta-analysis. Appetite, 143, 104438. 10.1016/j.appet.2019.104438 [DOI] [PubMed] [Google Scholar]
  33. R Core Team. (2022). R: A language and environment for statistical computing. https://www.R-project.org/ [Google Scholar]
  34. Radloff LS (1977). The CES-D Scale: A Self-Report Depression Scale for Research in the General Population. Applied Psychological Measurement, 1(3), 385–401. 10.1177/014662167700100306 [DOI] [Google Scholar]
  35. Reilly EE, Brown TA, Gray EK, Kaye WH, & Menzel JE (2019). Exploring the cooccurrence of behavioural phenotypes for avoidant/restrictive food intake disorder in a partial hospitalization sample. European Eating Disorders Review : The Journal of the Eating Disorders Association, 27(4), 429–435. 10.1002/erv.2670 [DOI] [PubMed] [Google Scholar]
  36. Revelle W (2022). p sych: Procedures for Psychological, Psychometric, and Personality Research (2.2.9) [Computer software]. Northwestern University, Evanston, IL. https://CRAN.R-project.org/package=psych. [Google Scholar]
  37. Roos CR, Sala M, Kober H, Vanzhula IA, & Levinson CA (2021). Mindfulness-based interventions for eating disorders: The potential to mobilize multiple associative-learning change mechanisms. The International Journal of Eating Disorders, 54(9), 1601–1607. 10.1002/eat.23564 [DOI] [PubMed] [Google Scholar]
  38. Sala M, Levinson CA, Kober H, & Roos CR (2023). A Pilot Open Trial of a Digital Mindfulness-Based Intervention for Anorexia Nervosa. Behavior Therapy, 54(4), 637–651. 10.1016/j.beth.2023.01.003 [DOI] [PubMed] [Google Scholar]
  39. Spielberger C, Gorsuch R, Lushene R, Vagg P, & Jacobs G (1983). Manual for the state-trait anxiety inventory. Consulting Psychologists Press. [Google Scholar]
  40. Stern CM, McPherson I, Dreier MJ, Coniglio K, Palmer LP, Gydus J, Graver H, Germine LT, Tabri N, Wang SB, Breithaupt L, Eddy KT, Thomas JJ, Plessow F, & Becker KR (2024). Avoidant/restrictive food intake disorder differs from anorexia nervosa in delay discounting. Journal of Eating Disorders, 12(1), 19. 10.1186/s40337-023-00958-x [DOI] [PMC free article] [PubMed] [Google Scholar]
  41. Thomas JJ, Becker KR, Breithaupt L, Murray HB, Jo JH, Kuhnle MC, Dreier MJ, Harshman S, Kahn DL, Hauser K, Slattery M, Misra M, Lawson EA, & Eddy KT (2021). Cognitive-behavioral therapy for adults with avoidant/restrictive food intake disorder. Journal of Rational-Emotive and Cognitive-Behavior Therapy: RET, 31(1), 47–55. 10.1016/j.jbct.2020.10.004 [DOI] [PMC free article] [PubMed] [Google Scholar]
  42. Thomas JJ, Becker KR, Kuhnle MC, Jo JH, Harshman SG, Wons OB, Keshishian AC, Hauser K, Breithaupt L, Liebman RE, Misra M, Wilhelm S, Lawson EA, & Eddy KT (2020). Cognitive-behavioral therapy for avoidant/restrictive food intake disorder: Feasibility, acceptability, and proof-of-concept for children and adolescents. The International Journal of Eating Disorders, 53(10), 1636–1646. 10.1002/eat.23355 [DOI] [PMC free article] [PubMed] [Google Scholar]
  43. Thomas JJ, Lawson EA, Micali N, Misra M, Deckersbach T, & Eddy KT (2017). Avoidant/Restrictive Food Intake Disorder: a Three-Dimensional Model of Neurobiology with Implications for Etiology and Treatment. Current Psychiatry Reports, 19(8), 54. 10.1007/s11920-017-0795-5 [DOI] [PMC free article] [PubMed] [Google Scholar]
  44. Waller G, Turner H, Tatham M, Mountford VA, & Wade TD (2019). Brief Cognitive Behavioural Therapy for Non-Underweight Patients: CBT-T for Eating Disorders. Routledge. https://play.google.com/store/books/details?id=cFSXDwAAQBAJ [Google Scholar]
  45. Wei T, & Simko V (2021). R package “corrplot”: Visualization of a Correlation Matrix [0.92]. https://github.com/taiyun/corrplot [Google Scholar]
  46. Wickham H (2016). ggplot2: Elegant Graphics for Data Analysis. Springer-Verlag; New York. https://ggplot2.tidyverse.org [Google Scholar]
  47. Wickham H, Averick M, Bryan J, Chang W, McGowan L, François R, Grolemund G, Hayes A, Henry L, Hester J, Kuhn M, Pedersen T, Miller E, Bache S, Müller K, Ooms J, Robinson D, Seidel D, Spinu V, … Yutani H (2019). Welcome to the tidyverse. Journal of Open Source Software, 4(43), 1686. 10.21105/joss.01686 [DOI] [Google Scholar]
  48. Wickham H, François R, Henry L, Müller K, Vaughan D (2023). dplyr: A Grammar of Data Manipulation. https://dplyr.tidyverse.org, https://github.com/tidyverse/dplyr [Google Scholar]
  49. Wisniewski L, Safer D, & Chen E (2007). Dialectical behavior therapy and eating disorders. In Dimeff LA(Ed.), Dialectical behavior therapy in clinical practice: Applications across disorders and settings, (pp (Vol. 363, pp. 174–221). Guilford Press, xx. https://psycnet.apa.org/fulltext/2007-14074-007.pdf [Google Scholar]
  50. Wonderlich SA, Peterson CB, & Smith TL (2015). Integrative Cognitive-Affective Therapy for Bulimia Nervosa: A Treatment Manual. Guilford Publications. https://play.google.com/store/books/details?id=8FHECQAAQBAJ [Google Scholar]
  51. Zickgraf HF, & Ellis JM (2018). Initial validation of the Nine Item Avoidant/Restrictive Food Intake disorder screen (NIAS): A measure of three restrictive eating patterns. Appetite, 123, 32–42. 10.1016/j.appet.2017.11.111 [DOI] [PubMed] [Google Scholar]

RESOURCES