Change in food choice during acute treatment and the effect on longer-term outcome in patients with anorexia nervosa.

BACKGROUND: Restriction of food intake is a central pathological feature of anorexia nervosa (AN). Maladaptive eating behavior and, specifically, limited intake of calorie-dense foods are resistant to change and contribute to poor long-term outcomes. This study is a preliminary examination of whether change in food choices during inpatient treatment is related to longer-term clinical course. METHODS: Individuals with AN completed a computerized Food Choice Task at the beginning and end of inpatient treatment to determine changes in high-fat and self-controlled food choices. Linear regression and longitudinal analyses tested whether change in task behavior predicted short-term outcome (body mass index [BMI] at discharge) and longer-term outcome (BMI and eating disorder psychopathology). RESULTS: Among 88 patients with AN, BMI improved significantly with hospital treatment (p < 0.001), but Food Choice Task outcomes did not change significantly. Change in high-fat and self-controlled choices was not associated with BMI at discharge (r = 0.13, p = 0.22 and r = 0.10, p = 0.39, respectively). An increase in the proportion of high-fat foods selected (ß = 0.91, p = 0.02) and a decrease in the use of self-control (ß = -1.50, p = 0.001) predicted less decline in BMI over 3 years after discharge. CONCLUSIONS: Short-term treatment is associated with improvement in BMI but with no significant change, on average, in choices made in a task known to predict actual eating. However, the degree to which individuals increased high-fat choices during treatment and decreased the use of self-control over food choice were associated with reduced weight loss over the following 3 years, underscoring the need to focus on changing eating behavior in treatment of AN.

Reduced dorsal fronto-striatal connectivity at rest in anorexia nervosa.

BACKGROUND: Anorexia nervosa (AN) is a serious psychiatric illness that remains difficult to treat. Elucidating the neural mechanisms of AN is necessary to identify novel treatment targets and improve outcomes. A growing body of literature points to a role for dorsal fronto-striatal circuitry in the pathophysiology of AN, with increasing evidence of abnormal task-based fMRI activation within this network among patients with AN. Whether these abnormalities are present at rest and reflect fundamental differences in brain organization is unclear. METHODS: The current study combined resting-state fMRI data from patients with AN (n = 89) and healthy controls (HC; n = 92) across four studies, removing site effects using ComBat harmonization. First, the a priori hypothesis that dorsal fronto-striatal connectivity strength - specifically between the anterior caudate and dlPFC - differed between patients and HC was tested using seed-based functional connectivity analysis with small-volume correction. To assess specificity of effects, exploratory analyses examined anterior caudate whole-brain connectivity, amplitude of low-frequency fluctuations (ALFF), and node centrality. RESULTS: Compared to HC, patients showed significantly reduced right, but not left, anterior caudate-dlPFC connectivity (p = 0.002) in small-volume corrected analyses. Whole-brain analyses also identified reduced connectivity between the right anterior caudate and left superior frontal and middle frontal gyri (p = 0.028) and increased connectivity between the right anterior caudate and right occipital cortex (p = 0.038). No group differences were found in analyses of anterior caudate ALFF and node centrality. CONCLUSIONS: Decreased coupling of dorsal fronto-striatal regions indicates that circuit-based abnormalities persist at rest and suggests this network may be a potential treatment target.

Anticipatory and Consummatory Responses Across Reward Domains in Adolescents With Anorexia Nervosa.

OBJECTIVE: Anorexia nervosa (AN) is characterized by a tendency to limit intake of food, with specific restriction of foods that are generally considered highly palatable. This observation raises questions about whether reward processing is disturbed in AN. This study examined whether adolescents with AN differ from healthy control peers (HC) in anticipatory and consummatory reward processing. METHOD: Adolescents with AN (n = 71) and HC (n = 41) completed the Temporal Experience of Pleasure Scale (TEPS). The TEPS Anticipatory Pleasure scale was divided into two further subscales (Food and Non-food). Anticipatory (Food and Non-food) and Consummatory Pleasure (Non-food) scores were compared between adolescents with AN and HC using independent t-tests. RESULTS: TEPS scores were significantly lower among adolescents with AN than HC in Anticipatory Pleasure Food (t(110) = 7.80, p < 0.001) and Non-food (t(110) = 4.36, p < 0.001), and Consummatory Pleasure (t(110) = 2.60, p = 0.01) subscales. When controlling for BDI score, there was no significant group difference in TEPS Consummatory Pleasure scores (t(108) = 0.88, p = 0.38). Among adolescents with AN, Food Anticipatory Pleasure was significantly negatively correlated with all EDE-Q subscales and global score (r(68) = -0.38, p = 0.002) and positively correlated with food intake at a laboratory buffet meal (r(61) = 0.53, p < 0.001). DISCUSSION: Measures of both anticipatory and consummatory reward were reduced among adolescents with AN with a short duration of illness. In this study, eating disorder symptoms were related to diminished reward responses in anticipation of food. Dampened anticipatory reward response may comprise a mechanism of illness in AN that should be subject to further study.

Self-referential processing in anorexia nervosa.

OBJECTIVE: Anorexia nervosa (AN) is a serious psychiatric illness associated with significant medical and psychiatric comorbidity and impairment. Theoretical models of AN and self-report studies suggest that negative self-evaluation (i.e., low self-esteem) is related to the development and maintenance of AN. The goal of this study was to extend findings from self-report methodology using a neurocognitive task that probes self-evaluation implicitly and explicitly. METHOD: We compared female adolescent and adult patients with AN (n = 35) and healthy controls (HC, n = 38) on explicit (i.e., endorsement of words as self-relevant), implicit (recall, recognition, reaction time), and composite (i.e., valence index, bias score, drift rates) indices of self-evaluation. We applied a drift-diffusion model to compute the drift rates, reflecting participants' decision-making process as to whether words were self-relevant. The association between self-evaluation indices and eating disorder severity was examined. RESULTS: There were significant Group × Condition interaction effects for all explicit and implicit measures (all p's ≤ .01), where the AN group endorsed, recalled, and recognized more negative relative to positive words than HC. The AN group had more negative valence index and bias scores, and slower drift rate away from negative words, reflecting more negative self-evaluation. The finding for recall was attenuated when individuals with depression were excluded. Measures of self-evaluation bias were not related to eating disorder severity. DISCUSSION: Using a neurocognitive approach that includes explicit and implicit indices of bias, results suggest that patients with AN have more negative self-evaluation. Due to the cross-sectional design, additional studies are needed to further evaluate directionality. PUBLIC SIGNIFICANCE: Negative self-evaluation/low self-esteem is thought to contribute to eating disorder symptoms. Findings of this study using a neurocognitive task to probe self-evaluation suggested that individuals with anorexia nervosa have more negative self-evaluation, reflected by endorsing and remembering more negative (than positive) words compared to healthy controls, and doing so faster. Targeting the construct of negative self-evaluation in treatment of AN may be warranted.

Eating disorder symptom non-endorsers in hospitalised patients with anorexia nervosa: Who are they?

OBJECTIVE: Impaired insight and illness denial are common in anorexia nervosa (AN). Missing an AN diagnosis may delay treatment and negatively impact outcomes. METHOD: The current retrospective study examined the prevalence and characteristics of AN symptom non-endorsement (i.e., scoring within the normal range on the Eating Disorder Examination Questionnaire [EDE-Q] or the Eating Disorder Examination [EDE] interview) in three independent samples of hospitalised patients with AN (N1 = 154; N2 = 300; N3 = 194). A qualitative chart review of a subsample of non-endorsers (N4 = 32) extracted reports of disordered eating behaviours observed by the treatment team. RESULTS: The prevalence of non-endorsement ranged from 11% to 34% across sites. Non-endorsers were more likely to be diagnosed with AN restricting type (AN-R) and reported fewer symptoms of co-occurring psychopathology than endorsers. Groups benefitted equally from treatment. The qualitative chart review indicated that objective symptoms of AN were recorded by staff in over 90% of non-endorsers. CONCLUSIONS: Eating disorder symptom assessments using the EDE-Q or EDE may miss symptomatology in up to a third of individuals hospitalised with AN. This study highlights the potential utility of multi-modal assessment including patient interviews, collateral informants, and behavioural observation to circumvent non-endorsement.

Neural Representations of Food-Related Attributes in the Human Orbitofrontal Cortex during Choice Deliberation in Anorexia Nervosa.

Decisions about what to eat recruit the orbitofrontal cortex (OFC) and involve the evaluation of food-related attributes such as taste and health. These attributes are used differently by healthy individuals and patients with disordered eating behavior, but it is unclear whether these attributes are decodable from activity in the OFC in both groups and whether neural representations of these attributes are differentially related to decisions about food. We used fMRI combined with behavioral tasks to investigate the representation of taste and health attributes in the human OFC and the role of these representations in food choices in healthy women and women with anorexia nervosa (AN). We found that subjective ratings of tastiness and healthiness could be decoded from patterns of activity in the OFC in both groups. However, health-related patterns of activity in the OFC were more related to the magnitude of choice preferences among patients with AN than healthy individuals. These findings suggest that maladaptive decision-making in AN is associated with more consideration of health information represented by the OFC during deliberation about what to eat.SIGNIFICANCE STATEMENT An open question about the OFC is whether it supports the evaluation of food-related attributes during deliberation about what to eat. We found that healthiness and tastiness information was decodable from patterns of neural activity in the OFC in both patients with AN and healthy controls. Critically, neural representations of health were more strongly related to choices in patients with AN, suggesting that maladaptive overconsideration of healthiness during deliberation about what to eat is related to activity in the OFC. More broadly, these results show that activity in the human OFC is associated with the evaluation of relevant attributes during value-based decision-making. These findings may also guide future research into the development of treatments for AN.

The next stages of treatment-oriented research: Commentary on Wade et al. (2023).

Treatments for eating disorders have established benefits; yet, current psychotherapies focus specifically on the cognitions and behaviors of the eating disorder. Wade et al. (2023) propose that the myriad symptoms and disorders that occur together with eating disorders merit specific attention in treatment research protocols. We seek to amplify the authors' call to take a fresh look at the characterization of eating disorders, and the need for treatment research to consider both the role of symptoms that occur as part and parcel of an eating disorder (such as mood, anxiety, and obsessionality) and the role of co-occurring disorders (such as obsessive-compulsive disorder and substance use disorders). We discuss additional aspects in the care of patients with eating disorders that were beyond the scope of Wade et al., such as the impact of systems of care, and consideration of medication trials. We propose that current research priorities (mechanism-based treatment development, transdiagnostic symptoms, and patient perspectives) can be leveraged to advance treatment research and develop a systematic approach to evaluation and treatment planning.

Integrating aspects of affect, reward, and cognition to develop more comprehensive models of binge-eating pathology.

Reward-related processes are an increasing focus of eating disorders research. Although evidence suggests that numerous distinct reward processes may contribute to eating pathology (e.g., reward learning and delay discounting), existing etiological models of reward dysfunction tend to focus on only a limited number of reward processes, and frequently lack specificity when identifying the individual reward processes hypothesized to contribute to dysregulated eating behavior. Moreover, existing theories have been limited in their integration of reward-related processes with other demonstrated risk and maintenance factors for eating disorders (e.g., affect and cognition), potentially contributing to underdeveloped models of eating pathology. In this article, we highlight five distinct reward processes with theorized or demonstrated relevance to eating disorders involving binge-eating, followed by a review of two well-established risk/maintenance factors for binge-eating pathology. We then introduce two novel models of binge eating onset and maintenance that integrate these factors (i.e., the Affect, Reward, Cognition models), and discuss methods for testing each of the models in future research. Ultimately, we hope that the proposed models provide a springboard for the continued evolution of more precise and comprehensive theories of reward dysfunction in the eating disorders, as well as the development of novel intervention approaches. PUBLIC SIGNIFICANCE STATEMENT: Eating disorders are associated with abnormalities in multiple domains of reward functioning. However, models of reward dysfunction within the eating disorders have not been well-integrated with prominent models of affect and cognition. This article presents two novel models of onset and maintenance for binge-eating pathology, which attempt to integrate observed reward abnormalities with other affective and cognitive processes implicated in binge-type eating disorders.

Perspectives on relapse prevention following intensive treatment of anorexia nervosa: A focus group study.

OBJECTIVE: Including the perspectives of individuals with lived experience of mental health issues is a critical step in research and treatment development. Focus groups with patients with a history of treatment for anorexia nervosa (AN) were conducted in anticipation of a clinical trial of Relapse Prevention and Changing Habits (REACH+). METHODS: Seven female adults (23-51 years) who had previously received inpatient treatment for AN, now in remission, participated in one of two semistructured focus groups. Rapid qualitative analysis was used to examine participants' contributions and identify common topics. RESULTS: Transcript analysis yielded three topics related to relapse prevention: (1) recovery aids, including a sense of agency in treatment decisions and finding new interests/passions, (2) recovery hindrances, such as lack of access to care, and (3) identification of members of support system. Aspects of REACH+ received positive feedback, such as continuity of care from the inpatient setting and the use of telehealth. Viewpoints differed with respect to the helpfulness of obtaining patient weights in treatment. The REACH+ online platform received positive comments regarding content and usability, as well as suggestions for additional content. DISCUSSION: Qualitative feedback from patients with a history of AN highlighted the value of engaging patients in their own treatment decisions, as well as in treatment design and innovation. Within this small group, there were differences of opinion about treatment components, specifically weight assessment, that suggest the need for further data. User-centered design provides opportunities to improve the acceptability and, therefore, dissemination of novel treatments. PUBLIC SIGNIFICANCE: Relapse prevention is a critical treatment need for patients with anorexia nervosa, as this illness too often follows a protracted course. There are challenges in both obtaining specialized care and in retaining patients in treatment. Here, patient perspectives on these challenges offer input to allow for optimization of relapse prevention treatment. Shared decision-making may be particularly valuable to support an individual's sense of agency and engagement in care.

Restrictive eating across a spectrum from healthy to unhealthy: behavioral and neural mechanisms.

BACKGROUND: Restriction of food intake is a central feature of anorexia nervosa (AN) and other eating disorders, yet also occurs in the absence of psychopathology. The neural mechanisms of restrictive eating in health and disease are unclear. METHODS: This study examined behavioral and neural mechanisms associated with restrictive eating among individuals with and without eating disorders. Dietary restriction was examined in four groups of women (n = 110): healthy controls, dieting healthy controls, patients with subthreshold (non-low weight) AN, and patients with AN. A Food Choice Task was administered during fMRI scanning to examine neural activation associated with food choices, and a laboratory meal was conducted. RESULTS: Behavioral findings distinguished between healthy and ill participants. Healthy individuals, both dieting and non-dieting, chose significantly more high-fat foods than patients with AN or subthreshold AN. Among healthy individuals, choice was primarily influenced by tastiness, whereas, among both patient groups, healthiness played a larger role. Dorsal striatal activation associated with choice was most pronounced among individuals with AN and was significantly associated with selecting fewer high-fat choices in the task and lower caloric intake in the meal the following day. CONCLUSIONS: A continuous spectrum of behavior was suggested by the increasing amount of weight loss across groups. Yet, data from this Food Choice Task with fMRI suggest there is a behavioral distinction between illness and health, and that the neural mechanisms underlying food choice in AN are distinct. These behavioral and neural mechanisms of restrictive eating may be useful targets for treatment development.

Eating disorders in the U.S. Medicare population.

OBJECTIVE: The social and economic burden of eating disorders is significant and often financially devastating. Medicare is the largest public insurer in the United States and provides coverage for older adults and some disabled individuals. This study explores prevalence, sociodemographic and clinical characteristics, and health care spending for Medicare enrollees with eating disorders. METHOD: A cross-sectional study was conducted with the nationally representative 20% sample of 2016 Medicare inpatient, outpatient, carrier, and home health fee-for-service claims and Medicare Advantage encounter records. Sociodemographic characteristics and comorbid somatic conditions were compared between individuals with versus without an eating disorder diagnosis. Mean spending was compared overall and separately for inpatient, outpatient, home health, and pharmacy claims. RESULTS: The sample included 11,962,287 Medicare enrollees of whom 0.15% had an eating disorder diagnosis. Compared to those without a 2016 eating disorder diagnosis, a greater proportion of individuals with an eating disorder were female (73.8% vs. 54.3%), under age 65 (41.6% vs. 15.5%), and dually eligible for Medicaid due to disability or low-income qualification (48.0% vs. 19.6%). Individuals with eating disorders had higher rates of comorbid conditions, with the greatest differences in cardiac arrythmias (35.3% vs. 19.9%), arthritis (40.1% vs. 26.6%), and thyroid conditions (32.2% vs. 19.4%). Spending was higher for enrollees with eating disorders compared to those without overall ($29,456 vs. $7,418) and across settings. DISCUSSION: The findings establish that eating disorders occur in the Medicare population, and that enrollees with these illnesses have risk factors associated with significant healthcare spending and adverse health outcomes.

Eating behavior in atypical anorexia nervosa.

OBJECTIVE: Atypical anorexia nervosa (AN) has been increasingly identified in the community and in clinical settings. Initial studies indicate that psychological symptoms are similar or more severe among patients with atypical AN, as compared with AN. This study examined whether eating behavior differed among patients with AN (n = 98), patients with atypical AN (n = 18), and healthy controls (HC, n = 75). METHOD: Adults and adolescents chose what to eat from a standardized, laboratory-based multi-item meal. Total intake, macronutrient composition, diet variety, and energy density were compared between groups. RESULTS: Both AN and atypical AN severely restricted caloric intake as compared with HC (431 ± 396 kcal and 340 ± 338 kcal vs. 879 ± 350 kcal, F2,188  = 35.4, p < .001). Individuals with AN and atypical AN did not differ in the mean intake of total calories or percentage of calories from fat (15.2 ± 25.2% vs. 11.5 ± 16.9%). DISCUSSION: This study demonstrates that individuals with atypical AN are at least as restrictive in their food intake as individuals with AN, and the restriction of dietary fat is particularly notable. Examination of eating behavior in a larger sample would be useful to replicate these findings. The current study highlights the need to understand maladaptive eating behavior in atypical AN in order to develop appropriate treatment recommendations. PUBLIC SIGNIFICANCE: Atypical anorexia nervosa is emerging as a prevalent eating disorder in community and clinical populations. The findings that patients with atypical anorexia nervosa limit calorie and fat intake in a pattern similar to that of patients with anorexia nervosa highlights the need for research to identify appropriate treatment strategies for normalization of eating patterns.

Optimizing relapse prevention and changing habits (REACH+) in anorexia nervosa.

INTRODUCTION: Relapse rates in anorexia nervosa (AN) are high, even after full weight restoration. This study aims to develop a relapse prevention treatment that specifically addresses persistent maladaptive behaviors (habits). Relapse Prevention and Changing Habits (REACH+) aims to support patients in developing routines that promote weight maintenance, encourage health, and challenge habits that perpetuate illness. The clinical trial design uses the Multiphase Optimization STrategy (MOST) framework to efficiently identify which components of treatment contribute to positive outcomes. METHODS: Participants will be 60 adults with AN who have achieved weight restoration in an inpatient setting. Treatment will consist of 6 months of outpatient telehealth sessions. REACH+ consists of behavior, cognitive, and motivation components, as well as food monitoring and a skill consolidation phase. A specialized online platform extends therapy between sessions. Participants will be randomly assigned to different versions of each component in a fractional factorial design. Outcomes will focus on maintenance of remission, measured by rate of weight loss and end-of-trial status. Interventions that contribute to remission will be included in an optimized treatment package, suitable for a large-scale clinical trial of relapse prevention in AN.

Deficient Goal-Directed Control in a Population Characterized by Extreme Goal Pursuit.

Research in computational psychiatry has sought to understand the basis of compulsive behavior by relating it to basic psychological and neural mechanisms: specifically, goal-directed versus habitual control. These psychological categories have been further identified with formal computational algorithms, model-based and model-free learning, which helps to provide quantitative tools to distinguish them. Computational psychiatry may be particularly useful for examining phenomena in individuals with anorexia nervosa (AN), whose self-starvation appears both excessively goal directed and habitual. However, these laboratory-based studies have not aimed to examine complex behavior, as seen outside the laboratory, in contexts that extend beyond monetary rewards. We therefore assessed (1) whether behavior in AN was characterized by enhanced or diminished model-based behavior, (2) the domain specificity of any abnormalities by comparing learning in a food-specific (i.e., illness-relevant) context as well as in a monetary context, and (3) whether impairments were secondary to starvation by comparing learning before and after initial treatment. Across all conditions, individuals with AN, relative to healthy controls, showed an impairment in model-based, but not model-free, learning, suggesting a general and persistent contribution of habitual over goal-directed control, across domains and time points. Thus, eating behavior in individuals with AN that appears very goal-directed may be under more habitual than goal-directed control, and this is not remediated by achieving weight restoration.

Reward Learning Through the Lens of RDoC: a Review of Theory, Assessment, and Empirical Findings in the Eating Disorders.

PURPOSE OF REVIEW: Reward-related processes may represent important transdiagnostic factors underlying eating pathology. Using the NIMH Research Domain Criteria as a guide, the current article reviews theories, behavioral and self-report assessments, and empirical findings related to reward learning in the eating disorders. RECENT FINDINGS: Data from behavioral tasks suggest deficits in reinforcement learning, which may become more pronounced with increasing disorder severity and duration. Self-report data strongly implicate positive eating and thinness/restriction expectancies (an element of reward prediction error) in the onset and maintenance of eating pathology. Finally, self-report measures of habit strength demonstrate relationships with eating pathology and illness duration; however, behavioral task data do not support relationships between eating pathology and a propensity towards general habit development. Existing studies are limited, but provide preliminary support for the presence of abnormal reward learning in eating disorders. Continued research is needed to address identified gaps in the literature.

Associations between mealtime anxiety and food intake in anorexia nervosa.

OBJECTIVE: A salient disturbance in anorexia nervosa (AN) is the persistent restriction of food intake. Eating behavior in AN is thought to be influenced by anxiety. The current study probed associations between mealtime anxiety and food intake among individuals with AN and healthy comparison individuals (HC). METHOD: Data were combined across three studies (total of 92 AN and 78 HC) for secondary data analysis. Participants completed a multiitem laboratory buffet meal and visual analogue scale assessments of pre-meal and post-meal anxiety. Linear regression models assessed the association between mealtime anxiety and calorie and fat intake at the meal, and whether associations differed by diagnostic group. RESULTS: Among individuals with AN, pre-meal anxiety was significantly associated with reduced calorie intake and reduced consumption of calories from fat at the meal; these associations were not observed among HC. There was no evidence for an association between calorie/fat intake at the meal and post-meal anxiety in either group. DISCUSSION: Treatments that target mealtime anxiety may improve eating and nourishment among individuals with AN. Interventions like exposure therapy that provide skills in overcoming mealtime anxiety might be enhanced by informing patients that post-meal anxiety is not related to intake.

Use of high-frequency repetitive transcranial magnetic stimulation to probe the neural circuitry of food choice in anorexia nervosa: A proof-of-concept study.

Repetitive transcranial magnetic stimulation (rTMS) is used to modulate neural systems and provides the opportunity for experimental tests of hypotheses regarding mechanisms underlying anorexia nervosa (AN). The present pilot study has investigated whether high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) to a region of the right dorsolateral prefrontal cortex (DLPFC) might be associated with change in food selection among adult inpatients with AN. Ten women received one session of sham and one session of HF-rTMS targeting the right DLPFC while completing a computerized Food Choice Task. Compared to sham, HF-rTMS was associated with changes in food ratings and food choice: inpatients reported higher healthiness ratings of low- and high-fat foods and selected a significantly greater proportion of high-fat foods over a neutrally rated reference item while receiving HF-rTMS. Findings suggest that HF-rTMS to the right DLPFC was associated with a reduction of fat avoidance on a food choice task among inpatients with AN and provide additional support for the possibility that this region, and related neural circuits, may underlie restrictive food choice. Research using rTMS to experimentally test neural mechanisms is needed to elucidate the underpinnings of AN and supports the development of novel treatment targets.

Between wellness, relapse, and remission: Stages of illness in anorexia nervosa.

OBJECTIVE: Psychiatric illnesses, like medical illnesses, can sometimes be considered as progressing through stages. Understanding these stages can lead to a better understanding of pathophysiology, and clarification of prognosis and treatment needs. Opinions from experts in the field of anorexia nervosa (AN) were sought to create a model of stages of illness. METHOD: The Delphi approach was used to achieve consensus from a panel of 31 individuals from a range of disciplines with expertise in AN. Over three iterative rounds, participants rated agreement with statements about an overall staging framework and definitions of specific stages. RESULTS: Agreement was reached about a longitudinal progression including Subsyndromal, Full Syndrome, Persistent Illness, and Partial and Full Remission. The panel achieved consensus in defining Subsyndromal AN as characterized by body image disturbance and mild to moderate restrictive eating. Overall, there was consensus that restrictive eating is central to the behavioral features of all stages of AN, and agreement that its absence is essential to any stage of health. There was little consensus about biological markers, other than body mass index, and no consensus about quality of life indices associated with different stages. DISCUSSION: This panel discussion yielded an expert-informed staging model for AN. This model now needs to be tested for its validity. The lack of consensus in several areas highlighted other research questions to address in order to develop an empirically valid and scientifically useful model of the progression of AN.

Habits are stronger with longer duration of illness and greater severity in anorexia nervosa.

OBJECTIVE: The aim of this study was to examine the relationship between habit strength and clinical features of anorexia nervosa (AN). Habit strength, separate from intention, relates to the persistence of behavior, and is measured by the Self-Report Habit Index (SRHI). We hypothesized that habit strength would be greater among individuals with AN than healthy controls (HC) and that habit strength would be associated with duration and severity of illness. METHOD: Participants were 116 women with AN (n = 69) and HC (n = 47) who completed the SRHI, the Eating Disorder Examination-Questionnaire (EDE-Q), and a multi-item laboratory meal. The SRHI assessed four domains and these subscales were averaged for the total score. RESULTS: Individuals with AN demonstrated significantly greater habit strength than HC in the total score (t114 = 7.00, p < .01), and within each domain (restrictive eating, compensatory behavior, delay of eating, and rituals). Total SRHI score was significantly associated with EDE-Q scores for both AN and HC groups (rAN = .59, pAN = <.001; rHC = .32, pHC = .030). Among patients, there was a significant association between SRHI and duration of illness (r = .38, p = .001). There was no significant association between SRHI and caloric intake (rAN = -.20, pAN = .10; rHC = -.25, pHC = .09). DISCUSSION: Habit strength was related to chronicity and severity of AN, suggesting that habit formation may play an important role in illness. These data suggest avenues for mechanism research and treatment development.

A comparison of food-based decision-making between restricting and binge-eating/purging subtypes of anorexia nervosa.

OBJECTIVE: By definition, restricting (ANR) and binge-eating/purging (ANBP) subtypes of anorexia nervosa (AN) differ in some manifestations of maladaptive eating behavior. This study aimed to determine whether the groups differ in the choices they make about what to eat, and whether there are differences in valuation related to food choice, using an experimental paradigm. METHOD: Inpatients with ANR (n = 40) and ANBP (n = 46) participated in a Food Choice Task. During the task, participants rated 76 food images for healthiness and tastiness, and choice preferences. Groups were compared in percent selection of high-fat and low-fat foods, value ratings of foods, and engagement of self-control in food choice. RESULTS: There were no differences between AN subtypes in healthiness or tastiness ratings, or in tendency to limit choice of high-fat foods. There was no difference between the groups in measures of self-control in food choice. DISCUSSION: Individuals with ANR and ANBP similarly manifest reduced choices of high-fat foods, with similar tendencies to undervalue the tastiness of high-fat foods. These results suggest that while individuals with ANR and ANBP differ across a range of clinical characteristics, the decision-making process associated with the maladaptive restriction of high-fat foods characteristic of AN is shared by both subtypes.