Interoception and disordered eating: A systematic review

Updating Prospective Self-Efficacy Beliefs About Cardiac Interoception in Anorexia Nervosa: An Experimental and Computational Study

Patients with anorexia nervosa (AN) typically hold altered beliefs about their body that they struggle to update, including global, prospective beliefs about their ability to know and regulate their body and particularly their interoceptive states. While clinical questionnaire studies have provided ample evidence on the role of such beliefs in the onset, maintenance, and treatment of AN, psychophysical studies have typically focused on perceptual and 'local' beliefs. Across two experiments, we examined how women at the acute AN (N = 86) and post-acute AN state (N = 87), compared to matched healthy controls (N = 180) formed and updated their self-efficacy beliefs retrospectively (Experiment 1) and prospectively (Experiment 2) about their heartbeat counting abilities in an adapted heartbeat counting task. As preregistered, while AN patients did not differ from controls in interoceptive accuracy per se, they hold and maintain 'pessimistic' interoceptive, metacognitive self-efficacy beliefs after performance. Modelling using a simplified computational Bayesian learning framework showed that neither local evidence from performance, nor retrospective beliefs following that performance (that themselves were suboptimally updated) seem to be sufficient to counter and update pessimistic, self-efficacy beliefs in AN. AN patients showed lower learning rates than controls, revealing a tendency to base their posterior beliefs more on prior beliefs rather than prediction errors in both retrospective and prospective belief updating. Further explorations showed that while these differences in both explicit beliefs, and the latent mechanisms of belief updating, were not explained by general cognitive flexibility differences, they were explained by negative mood comorbidity, even after the acute stage of illness.

Cardiac interoception in the museum: A novel measure of experience

Interoception is the perception of the body's internal signals in response to various external and internal stimuli. The present study uses a novel method adapted from the CARdiac Elevation Detection Task to examine cardiac interoception objectively and subjectively in a unique context-in the presence of art. Self-report questionnaires were used to measure subjective interoceptive awareness, subjective interoceptive accuracy, and aesthetic appreciation. For objective interoceptive accuracy and sensibility, a wearable device (Shimmer) measured heart rate (HR) and connected to a mobile application to prompt two questions: "Is your heart beating faster than usual?" and "How confident are you in your previous response?" Participants explored an art gallery for 40 minutes while the Shimmer measured their HR and randomly prompted them to answer the questions. Using a Generalized Estimating Equation model, interoceptive sensibility was not found to predict the odds of submitting a correct response. It was also found that art does not improve participants' perceptions of their HR. Finally, there was no relation between aesthetic appreciation and subjective or objective cardiac interoception. Despite lack of statistical significance, the current study's method presents an improved method by examining interoceptive accuracy in the moment under ecological conditions. To date, findings and methods used in interoception are inconsistent or flawed; the value in the current study lies in the development and demonstration of a method to examine how the environment influences the body and self-awareness across a wide variety of contexts, thereby offering a possible standardized measure of interoception for investigators to adopt.

A Pilot Feasibility Evaluation of a Heart Rate Variability Biofeedback App to Improve Self-Care in COVID-19 Healthcare Workers

COVID-19 exacerbated burnout and mental health concerns among the healthcare workforce. Due to high work stress, demanding schedules made attuned eating behaviors a particularly challenging aspect of self-care for healthcare workers. This study aimed to examine the feasibility and acceptability of a heart rate variability biofeedback (HRVB) mobile app for improving well-being among healthcare workers reporting elevated disordered eating during COVID-19. We conducted a mixed methods pre-mid-post single-arm pilot feasibility trial (ClinicalTrials.gov NCT04921228). Deductive content analysis of participants' commentary generated qualitative themes. Linear mixed models were used to examine changes in pre- mid- to post-assessment scores on well-being outcomes. We consented 28 healthcare workers (25/89% female; 23/82% Non-Hispanic White; 22/79% nurses) to use and evaluate an HRVB mobile app. Of these, 25/89% fully enrolled by attending the app and device training; 23/82% were engaged in all elements of the protocol. Thirteen (52%) completed at least 10 min of HRVB on two-thirds or more study days. Most participants (18/75%) reported being likely or extremely likely to continue HRVB. Common barriers to engagement were busy schedules, fatigue, and technology difficulties. However, participants felt that HRVB helped them relax and connect better to their body's signals and experiences. Results suggested preliminary evidence of efficacy for improving interoceptive sensibility, mindful self-care, body appreciation, intuitive eating, stress, resilience, and disordered eating. HRVB has potential as a low-cost adjunct tool for enhancing well-being in healthcare workers through positively connecting to the body, especially during times of increased stress when attuned eating behavior becomes difficult to uphold.

Are you how you eat? Aspects of self-awareness in eating disorders

Eating disorders (ED) are severe psychiatric disorders characterized by dysfunctional behaviors related to eating or weight control, with profound impacts on health, quality of life, and the financial burden of affected individuals and society at large. Given that these disorders involve disturbances in self-perception, it is crucial to comprehend the role of self-awareness in their prevalence and maintenance. This literature review presents different self-awareness processes, discussing their functioning across different levels of complexity. By deconstructing this concept, we can gain a better understanding of how each facet of self and personality relates to the symptoms of these disorders. Understanding the absence or impairment of self-awareness in ED holds significant implications for diagnosis, treatment, and overall management. By recognizing and comprehending the characteristics of self-awareness, clinicians can develop tailored interventions and evidence-based treatments for individuals with ED. Furthermore, this narrative review underscores the importance of considering temperament and personality factors in the context of ED, as temperament traits and personality characteristics may interact with self-awareness processes, influencing the development and maintenance of ED. Ultimately, the results highlight the pressing need for further research on the development of effective interventions and support strategies grounded in the aspects of self-awareness mechanisms for individuals affected by these disorders.

Bodily sensations and bariatric surgery: Links between interoceptive sensibility, intuitive and disordered eating behaviour in obesity and obesity surgery

OBJECTIVE

This study evaluated interoceptive sensibility, intuitive and disordered eating among bariatric candidates, operated individuals and individuals with obesity seeking non-surgical treatment.

METHOD

We recruited 57 individuals with obesity seeking nonsurgical weight-loss (IOB), 84 bariatric candidates (Pre) and 22 individuals post-bariatric surgery (Post) who responded to questionnaires: Multidimensional Assessment of Interoceptive Awareness, Intuitive Eating Scale-2 (IES-2), Dutch Eating Behaviour Questionnaire, Binge Eating Scale, State-Trait Anxiety Inventory, Beck's Depression Inventory.

RESULTS

Overall, the Post group manifested higher scores on 'Body-Listening' (F = 4.95, p = 0.01), 'Emotional Awareness' (F = 8.83, p < 0.001) and 'Trusting' (F = 6.71, p = 0.002) interoceptive dimensions, on the IES-2 total score (F = 5.48, p = 0.007) and 'Reliance on hunger and satiety cues' (F = 31.3, p < 0.001) when age was controlled. The IOB group presented higher scores on emotional (F = 3.23, p = 0.047) and binge eating (F = 5.99, p = 0.004). Among operated individuals, intuitive eating mediated the relationship between interoceptive sensibility dimensions and binge eating: 'Attention regulation' (54%) 'Self-regulation' (75.1%), 'Body listening' (94.09%) and 'Trusting' (84.9%).

CONCLUSIONS

Our results suggest the therapeutic potential of interoceptive sensibility and intuitive eating in obesity management in/beyond the bariatric context.

Cardiac interoception in Anorexia Nervosa: A resting-state heartbeat-evoked potential study

OBJECTIVE

A deficit in interoception - the ability to perceive, interpret and integrate afferent signals about the physiological state of the body - has been shown in Anorexia Nervosa (AN), and linked to altered hunger sensations, body dysmorphia, and abnormal emotional awareness. The present high-density electroencephalography (hdEEG) study aims to assess cardiac interoception in AN and to investigate its neural correlates, using an objective neurophysiological measure.

METHOD

Heartbeat-evoked potentials (HEPs) were computed from 5 min of resting-state EEG and electrocardiogram (ECG) data and compared between individuals with AN (N = 22) and healthy controls (HC) (N = 19) with waveform, topographic, and source imaging analyses.

RESULTS

Differences in the cortical representation of heartbeats were present between AN and HC at a time window of 332-348 ms after the ECG R-peak. Source imaging analyses revealed a right-sided hypoactivation in AN of brain regions linked to interoceptive processing, such as the anterior cingulate and orbitofrontal areas.

CONCLUSIONS

To the best of our knowledge, this is the first study using hdEEG to localise the underlying sources of HEPs in AN. Results point to altered interoceptive processing during resting-state in AN. As our participants had a short duration of illness, this might not be the consequence of prolonged starvation. Interventions targeted at interoception could provide an additional tool to facilitate recovery.

Early childhood appetitive traits and eating disorder symptoms in adolescence: a 10-year longitudinal follow-up study in the Netherlands and the UK

BACKGROUND

Obesity and eating disorders commonly co-occur and might share common risk factors. Appetite avidity is an established neurobehavioural risk factor for obesity from early life, but the role of appetite in eating disorder susceptibility is unclear. We aimed to examine longitudinal associations between appetitive traits in early childhood and eating disorder symptoms in adolescence.

METHODS

In this longitudinal cohort study, we used data from Generation R (based in Rotterdam, the Netherlands) and Gemini (based in England and Wales). Appetitive traits at age 4-5 years were measured using the parent-reported Child Eating Behaviour Questionnaire. At age 12-14 years, adolescents self-reported on overeating eating disorder symptoms (binge eating symptoms, uncontrolled eating, and emotional eating) and restrictive eating disorder symptoms (compensatory behaviours and restrained eating). Missing data on covariates were imputed using Multivariate Imputation via Chained Equations. Ordinal and binary logistic regressions were performed in each cohort separately and adjusted for confounders. Pooled results were obtained by meta-analyses. Sensitivity analyses were performed on complete cases using inverse probability weighting.

FINDINGS

The final study sample included 2801 participants from Generation R and 869 participants from Gemini. Pooled findings after meta-analyses showed that higher food responsiveness in early childhood increased the odds of binge eating symptoms (odds ratio [OR]pooled 1·47, 95% CI 1·26-1·72), uncontrolled eating (1·33, 1·21-1·46), emotional eating (1·26, 1·13-1·41), restrained eating (1·16, 1·06-1·27), and compensatory behaviours (1·18, 1·08-1·30) in adolescence. Greater emotional overeating in early childhood increased the odds of compensatory behaviours (1·18, 1·06-1·33). By contrast, greater satiety responsiveness in early childhood decreased the odds of compensatory behaviours in adolescence (0·89, 0·81-0·99) and uncontrolled eating (0·86, 0·78-0·95) in adolescence. Slower eating in early childhood decreased the odds of compensatory behaviours (0·91, 0·84-0·99) and restrained eating (0·90, 0·83-0·98) in adolescence. No other associations were observed.

INTERPRETATION

In this study, higher food responsiveness in early childhood was associated with a higher likelihood of self-reported eating disorder symptoms in adolescence, whereas greater satiety sensitivity and slower eating were associated with a lower likelihood of some eating disorder symptoms. Appetitive traits in children might be early neurobehavioural risk factors for, or markers of, subsequent eating disorder symptoms.

FUNDING

MQ Mental Health Research, Rosetrees Trust, ZonMw.

Interoceptive sensibility, intuitive eating, binge, and disordered eating behavior among individuals with obesity: A comparative study with the general population

The present study assessed the links between interoceptive sensibility, binge, disordered (emotional, restrained, and external) and intuitive eating among individuals with obesity (n = 57) and normal weight (n = 29). Individuals with obesity presented lower "attention regulation," "body-listening," and "trusting" interoceptive dimensions. When age was controlled, group differences on "trusting" remained significant. Individuals with obesity showed lower intuitive eating, higher emotional, and binge eating compared to controls. Higher "body listening," "eating for physical rather than emotional reasons," and "reliance on hunger and satiety cues" predicted lower binge eating whereas "external eating" predicted higher binge eating among individuals with obesity. Eating for physical reasons and reliance on hunger and satiety had protective mediating roles in the relationship between external and binge eating in both groups. Interoceptive sensibility and intuitive eating should conjointly serve as psychotherapeutic targets for disordered eating, obesity, and weight management.

Sensory processing across eating disorders: A systematic review and meta-analysis of self-report inventories

OBJECTIVE

This review investigated the extant literature regarding the relationship between eating disorder diagnoses and sensory processing as measured by validated and reliable self-report inventories. Increasing evidence highlights the role of sensory processing in cognitive functions. Sensory processing is implicated in mental-ill health, including eating disorders (ED) and body image disturbances. However, the pathophysiological underpinnings of sensory processing, encompassing exteroception and interoception, in relation to ED remain underexplored.

METHOD

We included studies involving participants aged 15 years or older with an eating disorder diagnosis confirmed by semi-structured or structured interviews. We further limited inclusion to articles using validated and reliable self-report instruments to measure sensory processing. Our meta-analysis focused on studies using the interoceptive awareness subscale from the second version of the Eating Disorder Inventory. We used the Critical Appraisal checklist for quasi-experimental studies to assess the quality of included articles.

RESULTS

There were 19 studies that met our inclusion criteria. Most studies showed moderate-to-high quality. Anorexia nervosa (AN) and bulimia nervosa (BN) were associated with heightened exteroception. Moreover, people with AN reported a heightened sense of taste compared to those with BN. Our meta-analysis comprising 10 studies, 19 samples, and 6382 participants revealed that AN (binge-purge subtype) and BN were associated with increased interoceptive difficulties compared to AN (restrictive subtype) or binge-eating disorder.

DISCUSSION

Overall, this review emphasizes the need for a deeper investigation into sensory processing, spanning both exteroception and interoception, in relation to ED. This may prove important for individualizing person-centered care.

PUBLIC SIGNIFICANCE

How people process internal, for example, hunger, and external, for example, taste and sensations is known to influence cognition and mental-ill health, including ED and body image disturbances. However, the ways in which sensory processing may contribute to ED are incompletely understood. We found that individuals with AN or BN experienced heightened exteroception, while people with an eating disorder characterized by purging reported increased interoceptive difficulties. These patterns could inform the development of more personalized treatments.

Recognition of others' interoceptive states in those with and without eating disorders

BACKGROUND

The ability to recognize one's own emotions is associated with one's ability to recognize others' emotions. Beyond the domain of emotion, however, the relationship between recognition of one's own internal states (interoception) and others' interoceptive states has not been investigated, either in the typical population or clinical groups with interoceptive difficulties (e.g. eating disorders; EDs).

METHOD

This study investigated recognition of one's own and others' internal states in adults with and without eating disorders, using a high frequency visual noise paradigm. Participants completed self-report measures of interoception, alexithymia (difficulties recognising one's own emotional internal states) and ED symptomatology, and the Heartbeat Counting Task measure of cardiac interoceptive accuracy.

RESULTS

Alexithymia was significantly negatively correlated with recognition of others' interoceptive states. EDs were not associated with difficulties recognising others' interoceptive states.

CONCLUSIONS

The ability to recognise one's own emotional internal states is associated with the recognition of others' interoceptive states, which may contribute to social skills and the ability to care for others.

Elevated interoceptive deficits in individuals with eating disorders and self-injurious thoughts and behaviors: A replication and extension

INTRODUCTION

People with eating disorders (EDs) frequently report self-injurious thoughts and behaviors (SITBs). We aimed to replicate and extend findings demonstrating greater interoceptive deficits according to SITB severity. We predicted that interoceptive deficits would be greater among people with versus without lifetime SITBs and among those with multiple suicide attempts compared with single attempts or nonsuicidal self-injury. We also predicted that interoception would be increasingly impaired with greater current suicidality severity.

METHOD

Adults (N = 118) seeking ED treatment reported current and lifetime SITBs upon admission to treatment. We used planned contrasts to compare interoceptive deficits (self-reported using the Eating Disorders Inventory) by SITB and current suicidality groups (assessed by self-report and clinical interview).

RESULTS

Interoceptive deficits were greater among people with any SITB history compared to those without. People with multiple suicide attempts did not differ in interoceptive deficits from those with single attempts or only nonsuicidal self-injury. Interoceptive deficits were elevated among those with any current suicidality compared to those with no suicidal symptoms; interoceptive deficits did not differ according to severity of suicidality.

CONCLUSION

Among those with EDs, interoceptive deficits are elevated among those with concurrent SITBs. Interventions aimed at improving interoception may reduce the risk for SITBs.

A conceptual framework on body representations and their relevance for mental disorders

Many mental disorders are accompanied by distortions in the way the own body is perceived and represented (e.g., eating disorders, body dysmorphic disorder including muscle dysmorphia, or body integrity dysphoria). We are interested in the way these distortions develop and aim at better understanding their role in mental health across the lifespan. For this purpose, we first propose a conceptual framework of body representation that defines this construct and integrates different perspectives (e.g., cognitive neuroscience, clinical psychology) on body representations. The framework consists of a structural and a process model of body representation emphasizing different goals: the structural model aims to support researchers from different disciplines to structure results from studies and help collectively accumulate knowledge about body representations and their role in mental disorders. The process model is reflecting the dynamics during the information processing of body-related stimuli. It aims to serve as a motor for (experimental) study development on how distorted body representations emerge and might be changed. Second, we use this framework to review the normative development of body representations as well as the development of mental disorders that relate to body representations with the aim to further clarify the potential transdiagnostic role of body representations.

The role of developmental caregiving programming in modulating our affiliation tendency and the vulnerability to social anxiety and eating disorders

Attachment is the evolutionarily-established process through which humans create bonds with others to receive care from them. The phenomenon is as essential to our physical survival as it is to our psychological development. An increasing number of studies demonstrates that in sensitive periods during the early years of life, our brain circuitry is programmed in the interactions with our caregivers, with the imprinting of information over multiple attachment dimensions. Adopting a basic brain-computer analogy, we can think of this knowledge as the psycho-social firmware of our mind. According to a recently proposed extension of the classical three-dimensional view, one attachment dimension - somaticity - concerns the caregiver's task of reflecting and confirming the child's (internal) states - such as sensations, emotions, and representations - to support the child's ability to identify and define those entities autonomously. Relying on multidisciplinary evidence - from neuroscientific, developmental, evolutionary, and clinical sources - we suggest that somaticity (H1) has the adaptive function to modulate our tendency to comply and affiliate with a reference group but also (H2) increases the vulnerability to developing Social Anxiety (SA) and Eating Disorders (EDs). We evaluate H1-H2, (1) indicating the evolutionary role of somaticity in modulating our affiliation tendency to optimize the ancestral threat-opportunity balance coming from infectious diseases and (2) showing the deep connection between SA-EDs and the features most closely related to somaticity - interoception and parenting style. Finally, we discuss three relevant implications of H1-H2: (A) Bringing into research focus the adaptive role of our firmware knowledge system versus the hardware (neural substrate) and software (higher cognition) ones. (B) Complementing the well-grounded Objectification and Allocentric Lock Theories, allowing us to integrate multiple levels of explanation on the etiology of psychopathology. (C) Suggesting the design of new psychological treatments. While not aiming to prove H1-H2, our analysis supports them and encourages their direct testing.

Pain experience in eating disorders: The mediating role of depression, alexithymia and interoceptive awareness

OBJECTIVE

Evidence suggests reduced sensitivity to pain due to high pain threshold in anorexia and bulimia nervosa and a possible role of depression, alexithymia and interoceptive awareness on pain experience. This study examined whether self-report and real-time evoked pain experience were mediated by depression, alexithymia and interoceptive awareness in a comprehensive sample of patients with eating disorders (ED).

METHOD

145 participants (90 ED, 55 healthy controls (HC)) underwent a real-time evoked examination of pain and completed self-report questionnaires for pain (Pain Detect Questionnaire (PD-Q), PD-Q VAS, Leeds Assessment of Neuropathic Symptoms and Signs), depression (BDI-II), interoceptive awareness Multidimensional Assessment of Interoceptive Awareness (MAIA), and alexithymia (TAS-20). Three mediation models, with ED diagnosis as independent variable, and BDI, MAIA and TAS-20 as mediators, were tested.

RESULTS

Participants with ED and HC exhibited similar pain type and intensity (self-report and real-time). Eating disorders diagnosis was associated with lower self-report pain intensity and non-neuropathic like pain experience (model 1-2). Depressive symptoms partially (model 1-2) or fully (model 3) mediated the association between ED diagnosis and pain experience, alone (model 1) or via alexithymia (model 3). Interoceptive awareness did not influence pain symptomatology.

DISCUSSION

ED diagnosis is associated with non-neuropathic and lower pain experience. However, concurrent depression and alexithymia are associated with higher pain symptoms and neuropathic features. These results could inform clinicians about the influence of psychopathology on pain experience in ED.

Thermosensation and emotion: Thermosensory accuracy in a dynamic thermal matching task is linked to depression and anxiety symptomatology

Interoception is related to the generation of bodily feelings and the awareness of ourselves as 'sentient beings', informing the organism about its bodily needs to guarantee survival. Previous studies have reported links among interoception, emotion processing, and mental health. For example, the alignment of interoceptive dimensions (i.e., accuracy, sensibility, awareness) can predict emotional symptoms, such as anxiety. Here, we aimed to investigate the relationship between the perception of a certain type of skin-mediated interoceptive signal, i.e., thermosensation, and self-reported depression, anxiety, and stress. One hundred seventy participants completed the Depression Anxiety Stress Scale (DASS-21) and a dynamic thermal matching task, a static temperature detection task, and a heartbeat counting task. Our results revealed that self-reported anxiety and depression were related to the perception of temperature on hairy and non-hairy skin, respectively: higher anxiety was related to better performance on the thermal matching task on the forearm, while higher depression was related to poorer performance on dynamic and static temperature tasks on the palm. Discrepancies between thermosensory accuracy and sensibility measures ('trait prediction error') were related to heightened anxiety, in line with previous studies. No significant correlations were found between DASS-21 scores and heartbeat counting accuracy. In conclusion, this study suggests that individual differences in thermosensory perception in different areas of the body are associated with self-reported anxiety and depression.

Beyond Gender: Interoceptive Sensibility as a Key Predictor of Body Image Disturbances

Body image disturbance (BID) involves negative attitudes towards shape and weight and is associated with lower levels of interoceptive sensibility (IS) (the subjective perceptions of internal bodily states). This association is considered a risk factor for developing eating disorders (EDs) and is linked to altered sensorimotor representations of the body (i.e., body schema). BIDs manifest across genders and are currently understudied in men. This study investigated gender-related differences in BID and its relationship to the body schema and IS. Data were collected from 86 men and 86 women. BID was assessed using questionnaires measuring self-objectification, state, and trait body dissatisfaction. IS was measured via the MAIA-2. The body schema was indexed via an embodied mental rotation task. Results showed that women reported higher BID than men across all scales. Gender differences in sub-components of interoceptive sensibility were found. Overall, both gender and interoceptive sensibility predicted BID. However, interoceptive sensibility exhibited its own unique association with BID beyond the influence of gender. BID, IS and gender were not significant predictors of performance in the body schema task. Therefore, while gender predicts differences in BID and interoceptive sensibility, there was no evidence of gender-related differences in body schema.

The multisensory mind: a systematic review of multisensory integration processing in Anorexia and Bulimia Nervosa

Individuals with Anorexia Nervosa and Bulimia Nervosa present alterations in the way they experience their bodies. Body experience results from a multisensory integration process in which information from different sensory domains and spatial reference frames is combined into a coherent percept. Given the critical role of the body in the onset and maintenance of both Anorexia Nervosa and Bulimia Nervosa, we conducted a systematic review to examine multisensory integration abilities of individuals affected by these two conditions and investigate whether they exhibit impairments in crossmodal integration. We searched for studies evaluating crossmodal integration in individuals with a current diagnosis of Anorexia Nervosa and Bulimia Nervosa as compared to healthy individuals from both behavioral and neurobiological perspectives. A search of PubMed, PsycINFO, and Web of Sciences databases was performed to extract relevant articles. Of the 2348 studies retrieved, 911 were unique articles. After the screening, 13 articles were included. Studies revealed multisensory integration abnormalities in patients affected by Anorexia Nervosa; only one included individuals with Bulimia Nervosa and observed less severe impairments compared to healthy controls. Overall, results seemed to support the presence of multisensory deficits in Anorexia Nervosa, especially when integrating interoceptive and exteroceptive information. We proposed the Predictive Coding framework for understanding our findings and suggested future lines of investigation.

Mental health meets computational neuroscience: A predictive Bayesian account of the relationship between interoception and multisensory bodily illusions in anorexia nervosa

Mental health disorders pose a significant challenge to society. The Bayesian perspective on the mind offers unique insights and tools that may help address a variety of mental health conditions. Psychopathological dysfunctions are often connected to altered predictive and active inference processes, in which cognitive and physiological pathogenic beliefs shape the clinical condition and its symptoms. However, there is a lack of general empirical models that integrate cognitive beliefs, physiological experience, and symptoms in healthy and clinical populations. In this study, we examined the relationship between altered predictive mechanisms, interoception, and pathological bodily distortions in healty individuals and in individuals suffering from anorexia nervosa (AN). AN patients (N=15) completed a Virtual Reality Full-Body Illusion along with interoceptive tasks twice: at hospital admission during an acute symptomatological phase (Time 1) and after a 12-week outpatient clinical weight-restoring rehabilitative program (Time 2). Results were compared to a healthy control group. Our findings indicated that higher levels of interoceptive metacognitive awareness were associated with a greater embodiment. However, unlike in healthy participants, AN patients' interoceptive metacognition was linked to embodiment even in multisensory mismatching (asynchronous) conditions. In addition, unlike in healthy participants, higher interoceptive metacognition in AN patients was related to prior abnormal bodily distortions during the acute symptomatology phase. Prediction errors in bodily estimates predicted posterior bodily estimate distortions after the illusion, but while this relationship was only significant in the synchronous condition in healthy participants, there was no significant difference between synchronous and asynchronous conditions in AN patients. Despite the success of the rehabilitation program in restoring some dysfunctional patterns in the AN group, prediction errors and posterior estimate distortions were present at hospital discharge. Our findings suggest that individuals with AN prioritize interoceptive metacognitive processes (i.e., confidence in their own perceived sensations rather than their actual perceptions), disregarding bottom-up bodily inputs in favour of their prior altered top-down beliefs. Moreover, even if the rehabilitative program partially mitigated these alterations, the pathological condition impaired the patients' ability to coherently update their prior erroneous expectations with real-time multisensory bottom-up bodily information, possibly locking the patients in the experience of a distorted prior top-down belief. These results suggest new therapeutic perspectives and introduce the framework of regenerative virtual therapy (RVT), which aims at utilizing technology-based somatic modification techniques to restructure the maladaptive priors underlying a pathological condition.

Interoceptive accuracy mediates the longitudinal relationship between attention deficit hyperactivity disorder (ADHD) inattentive symptoms and disordered eating in a community sample

Attention deficit hyperactivity disorder (ADHD) symptoms are associated with disordered eating and interoceptive deficits (as assessed by reliance on hunger/satiety cues) have been suggested as a potential mediating influence. The aim of this longitudinal study was to examine whether the association between ADHD symptoms and disordered eating is explained by deficits in specific facets of interoception. We also aimed to provide further evidence on the previously reported association between ADHD symptoms, negative mood and disordered eating. A community-based sample of 345 adult men and women (M age = 33.9, 72.5% women) completed questionnaires assessing disordered eating (restrictive and binge-type), ADHD symptoms, reliance on hunger/ satiety cues, specific facets of interoception (interoceptive accuracy and interoceptive sensibility) and negative mood at two timepoints over a 6-month period. We tested the mediating influence of reliance on hunger/satiety cues, facets of interoception and negative mood on the relationship between ADHD symptoms and disordered eating. Reliance on hunger/satiety cues mediated the relationship between inattentive symptoms of ADHD and both restrictive and binge-type eating. Interoceptive accuracy, but not sensibility mediated the relationship between inattentive ADHD symptoms and binge-type eating. Negative mood mediated the relationship between both ADHD symptom types and restrictive and binge-type eating. The results from this longitudinal study confirm that deficits in interoception and negative mood contribute to the relationship between ADHD symptoms and disordered eating and extend knowledge by highlighting interoceptive accuracy specifically as the most important facet of interoception in the relationship between inattentive symptoms and binge-type eating.

Dysfunctional decision-making in binge-eating disorder: A meta-analysis and systematic review

Binge-Eating Disorder (BED) involves anticipatory craving and urges, subjective loss-of-control during binge-eating episodes, and post-feeding psychological distress and guilt. Evidence indicates neurocognitive dysfunctions contribute to BED onset, maintenance, and treatment response. However, an integrated understanding of how cognitive processes underpin BED symptomology is lacking. We utilised a multi-stage decision-making model defining ten cognitive processes underpinning Preference Formation, Choice Implementation, Feedback Processing, and Flexibility/Shifting, to comprehensively review research published since 2013. We used preregistered PICOS criteria to assess 1966 articles identified from PubMed, PsycInfo, and Scopus database searches. This yielded 50 studies reporting behavioural cognitive tasks outcomes, comparing individuals with BED to controls with normal and higher weight. Meta-analyses revealed a unique profile of cognitive dysfunctions that spanned all decision-making stages. Significant deficits were evident in Uncertainty Evaluation, Attentional Inhibition, Choice Consistency, and Cognitive Flexibility/Set-shifting. We propose a novel model of dysfunctional decision-making processes in BED and describe their role in binge-eating behaviour. We further highlight the potential for cognitive interventions to target these processes and address the significant treatment gap in BED.

Examination of the two-step water load test as a measure of gastric interoception and associations with eating and weight/shape concerns in a nonclinical sample

OBJECTIVE

The current study extended research examining the validity of the two-step Water Load Test (WLT-II), an objective, laboratory-based measure of gastric interoception, by investigating the validity of the WLT-II in a nonclinical sample and testing its contribution to the prediction of eating and weight/shape concerns.

METHODS

Participants (n = 129, 73.6% cisgender female, M = 20.13 years old) completed the WLT-II Questionnaire and two-step WLT-II, as well as self-report measures of eating and weight/shape concerns (Eating Disorder Examination Questionnaire; EDE-Q) and interoception (Multidimensional Assessment of Interoceptive Awareness-2; Intuitive Eating Scale-2 Reliance on Hunger and Satiety), in the lab at a large southeastern university. Data analysis included repeated measures ANOVA, correlations, and a series of hierarchical linear regressions.

RESULTS

Participants reported considerably more discomfort after the "maximum fullness" trial compared to the "satiation" trial. The WLT-II's objective measure of gastric interoception (sat_%) was not significantly correlated with the self-report measures of interoception and did not predict EDE-Q Dietary Restraint, Eating Shame, or Weight/Shape Concerns. Unexpectedly, greater gastric sensitivity was associated with less EDE-Q Preoccupation/Restriction. Exploratory analyses suggested a possible nonlinear association.

DISCUSSION

These results support the validity of the WLT-II in its ability to create, measure, and distinguish between the states of satiation and maximum fullness. However, results also suggest additional work is needed to better understand what the WLT-II's sat_% measure is capturing, as well as investigate potential nonlinear associations of the WLT-II with disordered eating.

PUBLIC SIGNIFICANCE

Interoception, or the processing of internal body signals, shows important links to disordered eating. Despite the clear relevance of gastric interoception to disordered eating-such as the ability to detect satiety signals-existing research has relied on general, self-report measures of interoception. This study examined the utility of a laboratory-based measure of gastric interoception. Results suggested mixed support for its validity and utility for predicting eating and weight/shape concerns in a nonclinical population.

Confirmatory factor analysis of Acute Suicidal Affective Disturbance in a sample of treatment-seeking eating disorder patients

INTRODUCTION

We examined the factor structure of Acute Suicidal Affective Disturbance (ASAD) in individuals with eating disorders. ASAD is a proposed diagnosis with four symptoms: rapidly increasing suicidal intent, social or self-alienation, hopelessness regarding the previous symptoms, and overarousal.

METHODS

Patients with eating disorders (N = 378) completed self-report symptom questionnaires at admission to a partial hospitalization program for eating disorders. Using proxy measures, we conducted a confirmatory factor analysis (CFA) of the one-factor model of ASAD.

RESULTS

Initial model fit was poor. We iteratively revised the model to include theoretically-justified correlated residuals (i.e., those between items intended to measure the same ASAD symptom). After these modifications, model fit remained mediocre. We next conducted a multiple-group CFA to compare ASAD between individuals with the restricting subtype of anorexia nervosa (the "ANR" model, n = 145) and individuals with binge/purge disorders (i.e., bulimia nervosa and the binge-purge subtype of anorexia nervosa; the "BP" model, n = 234). The final model had mediocre fit with partial invariance between subgroups; the ASAD factor mean was higher in the BP model. We additionally tested a bifactor model, with similar findings.

LIMITATIONS

Our use of proxy measures of ASAD items may have resulted in imprecise measurement of ASAD symptoms, pointing to the importance of future research using validated measures of ASAD.

CONCLUSIONS

We found moderate support for ASAD in an eating disorder sample, with invariance between eating disorder phenotypes. Our findings suggest that the ASAD diagnosis may not fully generalize to eating disorder samples.

Temporal dynamics of interoceptive attention and positive and negative affect in adults engaging in disordered eating and nonsuicidal self-injury

OBJECTIVE

Interoception (the sense of the body's state) is associated with eating disorders and nonsuicidal self-injury, potentially through relationships with affect. We examined the relationship between interoceptive attention and both positive and negative affect.

METHODS

Participants (N = 128) who reported recent self-harm (i.e., disordered eating and/or non-suicidal self-injury) completed ecological momentary assessment for 16 days. Participants completed multiple daily assessments of affect and interoceptive attention. We then tested the temporal dynamic relationship between interoceptive attention and affect.

RESULTS

There was a relationship between positive affect and interoceptive attention such that people with higher average positive affect, and times when people were above their typical positive affect, were associated with higher interoceptive attention. There was a negative relationship between negative affect and interoceptive attention, such that people with higher average negative affect, and times when people were above their own typical negative affect, were associated with lower interoceptive attention.

CONCLUSIONS

Better mood may associate with greater willingness to attend to body sensations. Our findings support active inference models of interoception and highlight the importance of refining our understanding of the dynamic nature of interoception and its relationship with affect.

Risk factors for eating disorders: findings from a rapid review

BACKGROUND

Risk factors represent a range of complex variables associated with the onset, development, and course of eating disorders. Understanding these risk factors is vital for the refinement of aetiological models, which may inform the development of targeted, evidence-based prevention, early intervention, and treatment programs. This Rapid Review aimed to identify and summarise research studies conducted within the last 12 years, focusing on risk factors associated with eating disorders.

METHODS

The current review forms part of a series of Rapid Reviews to be published in a special issue in the Journal of Eating Disorders, funded by the Australian Government to inform the development of the National Eating Disorder Research and Translation Strategy 2021-2031. Three databases were searched for studies published between 2009 and 2021, published in English, and comprising high-level evidence studies (meta-analyses, systematic reviews, moderately sized randomised controlled studies, moderately sized controlled-cohort studies, or population studies). Data pertaining to risk factors for eating disorders were synthesised and outlined in the current paper.

RESULTS

A total of 284 studies were included. The findings were divided into nine main categories: (1) genetics, (2) gastrointestinal microbiota and autoimmune reactions, (3) childhood and early adolescent exposures, (4) personality traits and comorbid mental health conditions, (5) gender, (6) socio-economic status, (7) ethnic minority, (8) body image and social influence, and (9) elite sports. A substantial amount of research exists supporting the role of inherited genetic risk in the development of eating disorders, with biological risk factors, such as the role of gut microbiota in dysregulation of appetite, an area of emerging evidence. Abuse, trauma and childhood obesity are strongly linked to eating disorders, however less conclusive evidence exists regarding developmental factors such as role of in-utero exposure to hormones. Comorbidities between eating disorders and mental health disorders, including personality and mood disorders, have been found to increase the severity of eating disorder symptomatology. Higher education attainment, body image-related factors, and use of appearance-focused social media are also associated with increased risk of eating disorder symptoms.

CONCLUSION

Eating disorders are associated with multiple risk factors. An extensive amount of research has been conducted in the field; however, further studies are required to assess the causal nature of the risk factors identified in the current review. This will assist in understanding the sequelae of eating disorder development and in turn allow for enhancement of existing interventions and ultimately improved outcomes for individuals.

From Virtual Reality to Regenerative Virtual Therapy: Some Insights from a Systematic Review Exploring Inner Body Perception in Anorexia and Bulimia Nervosa

Despite advances in our understanding of the behavioral and molecular factors that underlie the onset and maintenance of Eating Disorders (EDs), it is still necessary to optimize treatment strategies and establish their efficacy. In this context, over the past 25 years, Virtual Reality (VR) has provided creative treatments for a variety of ED symptoms, including body dissatisfaction, craving, and negative emotions. Recently, different researchers suggested that EDs may reflect a broader impairment in multisensory body integration, and a particular VR technique-VR body swapping-has been used to repair it, but with limited clinical results. In this paper, we use the results of a systematic review employing PRISMA guidelines that explore inner body perception in EDs (21 studies included), with the ultimate goal to analyze the features of multisensory impairment associated with this clinical condition and provide possible solutions. Deficits in interoception, proprioception, and vestibular signals were observed across Anorexia and Bulimia Nervosa, suggesting that: (a) alteration of inner body perception might be a crucial feature of EDs, even if further research is needed and; (b) VR, to be effective with these patients, has to simulate/modify both the external and the internal body. Following this outcome, we introduce a new therapeutic approach-Regenerative Virtual Therapy-that integrates VR with different technologies and clinical strategies to regenerate a faulty bodily experience by stimulating the multisensory brain mechanisms and promoting self-regenerative processes within the brain itself.

Traumatic stress, body shame, and internalized weight stigma as mediators of change in disordered eating: a single-arm pilot study of the Body Trust® framework

To enhance access to evidence-based treatment it is increasingly important to evaluate scalable virtual programs that support the needs of those struggling with disordered eating. This study described a scientifically grounded, trauma-informed framework known as Body Trust,® and aimed to pilot test the preliminary effectiveness and mechanisms of change in a Body Trust® program to improve disordered eating. Using quality outcomes data, we examined 70 mostly white (87%) female-identifying (97%) individuals enrolled in a 6-module online program based in the Body Trust® framework (M_age = 45.5 ±10.9; M_BMI = 33.7 ±8.0). Putative mediators included traumatic stress, internalized weight stigma, and body shame. Outcomes were objective and subjective binge episodes, overvaluation of weight and shape, and eating concerns. Generalized estimating equations were applied to determine pre-to-post changes. We applied Montoya's MEMORE macro, the joint-significance test, and calculated 95% Monte Carlo confidence intervals to assess mediation. Significant pre-to-post improvements with medium to large effect sizes were detected for all outcomes and mediators (ps<.008). All hypothesized mechanisms supported mediation. Using the Body Trust® framework shows early promise for alleviating disordered eating symptoms through targeting traumatic stress, body shame, and internalized weight stigma. Given the program's use of mindfulness techniques, future research should test target mechanisms like interoception.

Knowing what you feel: Inferior frontal gyrus-based structural and functional neural patterns underpinning adaptive body awareness

BACKGROUND

Heightened body awareness (BA) is conducive for increasing understanding of bodily state and improves individuals' health and well-being. Although there has been cumulative research concentrating on the self-perceived tendency to focus on negatively valenced interoceptive sensations, the specific structural and functional neural patterns underlying BA and their role in the relationship between BA and individual well-being remain unclear.

METHODS

Voxel-based morphometry and whole brain functional connectivity analyses were conducted to examine the structural and functional neural patterns, respectively, in 686 healthy subjects. BA and subjective well-being were assessed using questionnaires.

RESULTS

BA was inversely related to gray matter volume of the right inferior frontal gyrus, opercular part (IFGoperc). Higher BA was correlated with enhanced IFGoperc-precuneus and IFGoperc-anterior supramarginal gyrus connectivities, and with decreased IFGoperc-lateral occipital cortex and IFGoperc-medial frontal cortex connectivities. The inferior frontal gyrus, triangular part (in the fronto-parietal task control network) acted as the hub that linked the sensory/somatomotor network, the default mode network, and the dorsal and ventral attention network. The IFGoperc-precuneus connectivity moderated the association between BA and subjective well-being.

LIMITATIONS

We were unable to rank all the networks by their relative importance, because the absolute weighted value in each module was not calculated.

CONCLUSION

Our findings demonstrated that BA was reflected by specific neural patterns mainly involved in cognitive-affective control, attentional and self-referential processing, as well as multisensory integration, which could offer some references for current therapies (e.g., mindfulness, yoga training) that are dedicated to solving health problems and improving individual well-being.

Time evaluation and its accuracy in eating disorders: differences in relation to interoceptive awareness

PURPOSE

Time evaluation has been poorly studied in eating disorder (ED) patients despite its relationship with body awareness, which is a core psychopathological feature in EDs and is influenced by impulsivity, interoception, and working memory. This study aims to evaluate time estimation and its accuracy across the ED spectrum in connection with specific and general psychopathology.

METHODS

A group of 215 women was enrolled in a computerized task involving the estimation of 1-min intervals. Impulsivity and body awareness constructs (self-monitoring, depersonalization, interoceptive deficit) were evaluated and examined for significant correlations with time estimation and the accuracy of the measure.

RESULTS

Patients with EDs showed an impaired ability to estimate time, with an accuracy that positively correlated with compulsive self-monitoring (p = 0.03). Differences between diagnostic subgroups showed an overestimation of time in anorexia nervosa patients and an underestimation of time in binge eating disorder patients, whose time estimation was also less accurate.

CONCLUSION

The relationship between time estimation and compulsive self- monitoring might corroborate the presence of an imbalanced integration of information in patients with EDs that was not present in the community women included in the study. Time perception should be further evaluated in the ED field, and longitudinal changes due to psychopathological recovery or BMI changes should be examined.

LEVEL OF EVIDENCE

Level III: Evidence obtained from a well-designed cohort or case-control analytic study.

Associations between inattention and impulsivity ADHD symptoms and disordered eating risk in a community sample of young adults

BACKGROUND

Symptoms of attention deficit hyperactivity disorder (ADHD) and trait impulsivity have been associated with disordered eating but are seldom assessed in community studies, or longitudinally and little is known about the mediating mechanisms.

METHODS

We tested associations between ADHD symptoms and disordered eating cross-sectionally and between trait impulsivity and disordered eating longitudinally. We utilised data from a normative cohort of young adults (642 participants: 65% female, M_age = 23 years). Participants were classified as high risk or low risk for disordered eating using the SCOFF instrument. In the first two steps of both cross-sectional and longitudinal hierarchical logistic regression models, demographics and covariates were entered. For the cross-sectional regression, Adult ADHD self-report scale (ASRS) scores, separated into inattentive and hyperactive/impulsive symptoms, were entered in the third step. In a separate longitudinal model, Barratt impulsivity scale subscales (attentional, motor and non-planning impulsivity) were entered in the third step. Depression, as assessed by the moods and feelings questionnaire (MFQ), was examined as a mediator.

RESULTS

Cross-sectionally, sex, MFQ score and inattentive symptoms predicted disordered eating risk (model R² = 20%). Longitudinally, sex, MFQ score and attentional impulsivity predicted disordered eating risk (model R² = 16%). The relationship between inattentive symptoms and the disordered eating risk was partially mediated by MFQ score, whereas the relationship between attentional impulsivity and the disordered eating risk was fully mediated by MFQ scores.

CONCLUSIONS

These data highlight (1) a specific role for inattentive symptoms of ADHD and (2) the importance of both depression and impulsivity in predicting eating disorder risk.

A snapshot of eating behaviors in undergraduate college students living in South Florida

Objective: To examine a) whether college students' eating behaviors are different by students' sex and/or body mass index (BMI) categories and b) the correlations between college students' eating behaviors and the degree to which they rely on internal bodily signals for food intake. Participants: Undergraduate college students 18-24 years old at a public university located in South Florida. Methods: Eligible students answered questionnaires to examine interoception, intuitive eating, and eating behaviors including emotional eating, restrained eating, cognitive restraint, external eating, and uncontrolled eating. Pearson correlation and independent t test were used (significance: p < 0.05). Results: Females reported lower interoception, intuitive eating, and higher emotional eating than males. Students with lower BMI had higher intuitive eating and lower restrained eating. Interoception was positively correlated with intuitive eating and negatively correlated with emotional, uncontrolled, restrained, and external eating. Conclusion: College students who have a better connection with their bodily signals have healthier eating behaviors and lower BMI.

The role of interoception in the overlap between eating disorders and autism: Methodological considerations

Significant comorbidity has been demonstrated between feeding and eating disorders and autism. Atypical interoception (perception of bodily signals) may, at least in part, be responsible for this association, as it has been implicated in the aetiology of both conditions. However, significant methodological limitations are impeding progress in this area. This paper provides a brief overview of how interoception has been linked to autism and feeding and eating disorders in both adolescent and adult populations before identifying several issues with current measures of interoception. We suggest that methodological issues may be contributing to the inconsistency in the empirical literature, and provide suggestions for future research.

Atypical interoception is linked to both feeding and eating disorders, and autism and may contribute to the comorbidity between the two.

Existing measures of interoception across cardiac, gastric and respiratory domains are severely limited.

Novel and better‐validated measures of interoception will allow us to better understand the clinical potential of interoceptive training.

‘When hunger makes everything better looking!’: The effect of hunger on the aesthetic appreciation of human bodies, faces and objects

Background

Research evidence suggests that physiological state of hunger might affect preference for female body weight, such that hungrier, compared to satiate, men prefer heavier body weight and rate as more attractive heavier female figures. Here, we seek to extend these findings by comparing the effects of fasting and snack on aesthetics judgements of the bodies and faces of conspecifics and of objects in a sample of female and male participants.

Methods

Forty-four participants (women: n = 21, mean age = 23.70 yrs ± 0.62) provided aesthetic liking judgments of round and slim human bodies, faces and objects, under at least 12 h of overnight fasting and immediately after having eaten a snack (i.e., bananas). An anthropometric measure of adiposity (i.e., Body Mass Index, BMI) was also collected from each observer.

Results

Overall, we found that participants’ aesthetic judgements were higher for slim stimuli compared to round ones. However, after fasting, participants rated round stimuli as more attractive compared to when they had a snack. This hunger-based shift in ratings not only was apparent when stimuli depicted a human body or face, but also when they depicted an object, thus suggesting a general modification of observers’ aesthetic preference related to hunger. Importantly, this effect was modulated by participants’ BMI so that only participants with a high BMI provided higher aesthetic judgements for round stimuli after fasting than after a snack.

Conclusions

Our results demonstrated that both the modification of the physiological state and the individual differences in adiposity level of the observers might affect the aesthetic appreciation of the external world.

A Pilot Feasibility Study of Reconnecting to Internal Sensations and Experiences (RISE), a Mindfulness-Informed Intervention to Reduce Interoceptive Dysfunction and Suicidal Ideation, among University Students in India

Although 20% of the world’s suicides occur in India, suicide prevention efforts in India are lagging (Vijayakumar et al., 2021). Identification of risk factors for suicide in India, as well as the development of accessible interventions to treat these risk factors, could help reduce suicide in India. Interoceptive dysfunction—or an inability to recognize internal sensations in the body—has emerged as a robust correlate of suicidality among studies conducted in the United States. Additionally, a mindfulness-informed intervention designed to reduce interoceptive dysfunction, and thereby suicidality, has yielded promising initial effects in pilot testing (Smith et al., 2021). The current studies sought to replicate these findings in an Indian context. Study 1 (n = 276) found that specific aspects of interoceptive dysfunction were related to current, past, and future likelihood of suicidal ideation. Study 2 (n = 40) was a small, uncontrolled pre-post online pilot of the intervention, Reconnecting to Internal Sensations and Experiences (RISE). The intervention was rated as highly acceptable and demonstrated good retention. Additionally, the intervention was associated with improvements in certain aspects of interoceptive dysfunction and reductions in suicidal ideation and eating pathology. These preliminary results suggest further testing of the intervention among Indian samples is warranted.

Decreased interoceptive accuracy in children with autism spectrum disorder and with comorbid attention deficit/hyperactivity disorder

Interoception refers to the awareness of internal physiological state. Several previous studies reported that people with autism spectrum disorders (ASD) and adults with attention-deficit/hyperactivity disorder (ADHD) have diverse patterns of interoception, but the extent of literature is limited and inconsistent. This study aimed to investigate the interoceptive accuracy (IA) in children with ASD, children with comorbid ASD and ADHD, and typically developing (TD) children with high and low levels of autistic traits. We administered the eye-tracking interoceptive accuracy task (EIAT) to 30 children with ASD, 20 children with comorbid ASD and ADHD, and 63 TD controls with high and low levels of autistic traits. Parent-report scales concerning ASD and ADHD symptoms were collected. ASD children with and without comorbid ADHD both exhibited lower IA than TD children. Reduced IA was also found in TD children with high-autistic traits relative to those with low-autistic traits. IA was negatively correlated with autistic and ADHD symptoms. Atypical cardiac interoception could be found in children with ASD. Difficulties in sensing and comprehending internal bodily signals in childhood may be related to both ASD and ADHD symptoms.

General versus hunger/satiety-specific interoceptive sensibility in predicting disordered eating

Dysfunctional interoceptive processing of hunger and satiety cues is particularly relevant to disordered eating behaviors. However, researchers often rely on general measures of interoceptive sensibility (IS¹; self-reported experience of internal bodily cues) which conflate interoceptive processes across biological systems (e.g., gastric, cardiac) when assessing the role of interoception in disordered eating. Participants (N = 213; 50% female, age M = 20.77 years) were recruited from a large southeastern university for this online study and completed the Intuitive Eating Scale-2 (hunger/satiety-specific), the Multidimensional Assessment of Interoceptive Awareness-2 (general), and the Eating Disorder Inventory Interoceptive Awareness Subscale (general) as measures of IS. The Eating Pathology Symptoms Inventory was used to assess disordered eating attitudes and behaviors. Controlling for sex and body mass index, hunger/satiety-specific IS was associated with binge eating, purging, and cognitive restraint over and above general IS measures and emerged as the dominant predictor of each. Hunger/satiety-specific IS did not predict restricting behavior. Dysfunctional processing of hunger and satiety cues may be a particularly important risk factor to target in screenings and interventions for disordered eating. Findings highlight the importance of careful selection of IS measures in research and targeting hunger/satiety-specific IS in clinical interventions for disordered eating.

Interoception and obesity: a systematic review and meta-analysis of the relationship between interoception and BMI

BACKGROUND

Interoception refers to the processes by which we sense, interpret and integrate signals originating from within the body. Deficits in interoception have been linked to higher BMI and may contribute to weight gain. However, there have been conflicting findings and it is not clear how higher BMI is associated with different facets of interoception, such as interoceptive accuracy (the ability to detect internal signals) and sensibility (the tendency to attend to internal signals).

METHODS

We conducted a systematic review and meta-analysis of studies that measured interoception and BMI. We examined relationships between interoception and BMI in children and adults separately and as a function of interoceptive facet and measure. In sensitivity analyses, we tested for evidence of publication bias and whether the results were consistent when studies with a high risk of bias were excluded.

RESULTS

A total of 87 articles were eligible for inclusion. In adults (121 effects, 10,425 participants), there was cross-sectional evidence of higher BMI being associated with overall deficits in interoception (r = -0.054, 95% CI: -0.084 to -0.025) and this was consistent across sensitivity analyses. There was no statistically significant evidence of moderation by interoceptive facet or measure, although there was some variability in effect size estimates based on interoceptive facet and measures. A smaller meta-analysis limited to studies that compared participants with normal weight vs. overweight/obesity indicated poorer interoception in participants with overweight/obesity (SMD = -0.39, 95% CI -0.60 to -0.18).

CONCLUSIONS

In cross-sectional studies, deficits in interoception are associated with higher BMI. However, it remains unclear whether deficits in interoception contribute to or are a consequence of weight gain and obesity.

Affective touch topography and body image

Recent evidence suggests that altered responses to affective touch—a pleasant interoceptive stimulus associated with activation of the C-Tactile (CT) system—may contribute to the aetiology and maintenance of mental conditions characterised by body image disturbances (e.g., Anorexia Nervosa). Here, we investigated whether tactile pleasantness and intensity differ across body sites, and if individual differences in dysmorphic appearance concerns and body and emotional awareness might be associated with touch perceptions across body sites. To this end, we measured perceived pleasantness and intensity of gentle, dynamic stroking touches applied to the palm, forearm, face, abdomen and back of 30 female participants (mean age: 25.87±1.17yrs) using CT-optimal (3 cm/s) and non-CT optimal (0.3 and 30 cm/s) stroking touch. As expected, participants rated CT-targeted touch as more pleasant compared to the two non-CT optimal stroking touch at all body sites. Regardless of stroking velocity, touch applied to the abdomen elicited the lowest pleasantness ratings. Lower levels of emotional awareness, greater levels of interoceptive sensibility and of dysmorphic concerns were associated with lower preference for CT-optimal stroking touch applied to the forearm and the back. These findings begin to elucidate the link between CT sensitivity, dysmorphic appearance concerns and body and emotional awareness, which may have implications for future research looking to inform early interventions. Addressing impaired processing of affective interoceptive stimuli, such as CT-targeted touch, may be the key to current treatment approaches available for those populations at risk of disorders characterised by body image disturbance.

Treatment Outcomes and Trajectories of Change in Patients Attributing Their Eating Disorder Onset to Anti-obesity Messaging

OBJECTIVE

Given the increased prevalence of eating disorders (EDs) among individuals higher on the weight spectrum, we aimed to 1) report the prevalence of ED patients in higher levels of care (residential, partial hospitalization, and intensive outpatient) attributing the onset of their ED to anti-obesity messaging, 2) report the most commonly recollected sources of those messages, and 3) determine if those attributing the onset of their ED to anti-obesity messaging a) enter, b) exit, and c) respond to treatment differently from peers who did not.

METHODS

This retrospective cohort study used data from 2901 patients receiving ED treatment in higher levels of care at a US-based center between 2015 and 2018. Multilevel models examined differences in ED symptoms and trajectories of change over time. NVivo was used to analyze the patients' comments about sources of messages.

RESULTS

Eighteen percent attributed their ED onset to anti-obesity messaging, 45% did not, and 37% were unsure. Of those providing comments, the most common sources included the following: educational curriculum/school context (45.9%), media/Internet (24.7%), health care (10.4%), family (9%), and peer bullying (3.7%). At admission, patients attributing their ED onset to anti-obesity messaging had more severe ED symptoms than those who did not (γ = 0.463, standard error [SE] = 0.086, p < .001) and those who were unsure (γ = 0.288, SE = 0.089, p < .001); no differences were evident at discharge (p > .483). During phase 2 of treatment, patients attributing their ED onset to anti-obesity messaging improved faster than those who did not (γ = 0.003, SE = 0.001, p = .008) and those who were unsure (γ = 0.003, SE = 0.001, p = .014).

CONCLUSIONS

Anti-obesity messaging may put vulnerable individuals at risk for EDs. We recommend increasing weight bias training for school personnel and health care professionals. To reduce health disparities, we also suggest the promotion of weight-neutral health-enhancing self-care practices in media and public health campaigns, legislative policies, and health care overall.

Individual differences in sensory and expectation driven interoceptive processes: a novel paradigm with implications for alexithymia, disordered eating and obesity

Those with disordered eating and/or obesity often express difficulties in sensing or interpreting what is happening in the body (interoception). However, research is hindered by conceptual confusion, concerns surrounding domain specificity, and an inability to distinguish sensory (bottom-up) and expectation driven (top-down) interoceptive processes. A paradigm was therefore developed from an active inference perspective. Novel indices were computed and examined in those with alexithymia: a personality associated with interoceptive deficits and disordered eating. The paradigm successfully identified individuals driven by sensations rather than expectations: alexithymia was characterized by attenuated prior precision (a larger divergence between pre-prandial and post-prandial satiety, and low expectation confidence), and increased prediction error (a higher correlation between changes in hunger and blood glucose, and greater rebound hunger after a sensory incongruent drink). In addition, those with a higher BMI were less confident and had a larger anticipated satiety divergence. These findings demonstrate the need to move beyond existing paradigms such as the Satiety Quotient and Heartbeat Counting Task which may have limited our understanding of eating behaviour.

Virtual reality in the treatment of eating disorders

Over the last 25 years, virtual reality (VR) has offered innovative solutions for targeting different key symptoms of eating disorders: from craving to negative emotions, from attentional biases to body dissatisfaction. The present narrative review assesses the existing literature in these areas trying to identify their different levels of clinical evidence. Specifically, the review presents four clinical approaches based upon VR and their implications in the treatment of eating disorders: VR cue exposure, VR reference frame shifting, VR for correcting body distortions and attentional biases. In general, existing findings demonstrate the clinical value of VR. On one side, the present review suggests that two VR-based techniques-VR exposure and reference frame shifting-have a significant research support and provide a possible advantage over traditional cognitive-behavioural therapy (CBT) for bulimia nervosa and binge eating disorder. On the other side, two emerging VR applications-multisensory body illusions and the use of VR for the modification of attentional biases-even if supported by preliminary data still need further research.

Pain, eating behavior, and weight outcomes in adolescent girls

OBJECTIVE

In adults, pain is prospectively associated with overweight/obesity and concurrently associated with dysregulated eating, with evidence for stronger associations in women than men. This study aimed to evaluate whether similar associations among pain response, BMI, and loss of control (LOC) eating are also evident in adolescent girls.

METHOD

Girls (n = 202) completed the cold pressor test (CPT) at age 10, and BMI and LOC eating were assessed annually from ages 10-16 years. Generalized linear models were used to test associations between pain tolerance (total immersion time) and threshold (latency to highest pain rating), and changes in BMI and LOC eating.

RESULTS

Lower pain tolerance and threshold at age 10 were associated with increases in LOC eating from age 10 to 16 (tolerance: B < -.01, SE < .01, p = .005; threshold: B = -.03, SE = .01, p = .0118). No significant associations were observed between pain tolerance/threshold and increasing BMI.

DISCUSSION

Pain responsivity in childhood is associated with increases in dysregulated eating from childhood to adolescence. These findings provide support for the early development of an interface between pain and eating behaviors.

Interoception, eating behaviour and body weight

BACKGROUND

Interoception refers to the process of identifying and listening to internal bodily signals, which may be a modifiable determinant of appetite regulation and weight gain. The objective was to examine whether the extent to which self-reported interoception is associated with higher BMI is explained by eating behavior traits.

METHODS

UK adults (N = 1181, 49% female, 53% with overweight/obesity) completed validated self-report measures of interoception, habitual tendencies to eat in response to satiety signals (intuitive eating), emotional over-eating and other eating traits.

RESULTS

Poorer self-reported ability to detect interoceptive signals (deficits in interoceptive accuracy) was predictive of higher BMI (r = - 0.07 (95% CI -0.13; -0.01), p < .05). In parallel mediation analyses, participants with poorer interoceptive accuracy were significantly less likely to report considering satiety signals when eating and this explained the cross-sectional association between interoceptive accuracy and higher BMI. There was also some evidence that participants with poorer interoceptive accuracy were more likely to report emotional overeating and this also in part explained why interoceptive accuracy was predictive of higher BMI.

CONCLUSIONS

Deficits in interoception may decrease the likelihood that satiety signals are integrated into eating behaviour related decision making and in doing so contribute to higher BMI.

Intuitive eating mediates the relationship between interoceptive accuracy and eating disorder risk

Research supports an association between altered interoceptive accuracy, or the ability to accurately monitor sensations from the body, and disordered eating. However, the behavioral mechanism through which interoceptive accuracy may influence eating behaviors is unclear. Intuitive eating, the ability to regulate food intake according to visceral cues of hunger and satiety, is positively related to interoceptive accuracy and negatively related to disordered eating. Therefore, we hypothesized that interoceptive accuracy would be negatively associated with intuitive eating which would, in turn, influence eating disorder risk. A mediation analysis was performed to test this hypothesis in a sample of 41 undergraduate women who completed a heartbeat counting task to assess interoceptive accuracy, followed by self-report measures of intuitive eating ability and eating disorder risk. We found that eating for physical rather than emotional reasons and reliance on hunger and satiety cues, two aspects of intuitive eating, mediated the relationship between interoceptive accuracy and eating disorder risk. Although further research is necessary, it is possible that findings regarding the association between interoceptive accuracy and intuitive eating may inform the development of eating disorder prevention efforts.

Psychological Risk Factors for the Development of Restrictive and Bulimic Eating Behaviors: A Polish and Vietnamese Comparison

The aim of this paper is to identify psychological factors which are culture specific or common predictors for restrictive and bulimic behaviors towards eating for young women raised in different cultures. The study included 661 young women from Poland (n = 233) and Vietnam (n = 428). Subjects filled-in the Eating Disorders Inventory (EDI-3) and the Multidimensional Body-Self Relations Questionnaire-Appearance Scales (MBSRQ-AS), and body measurements were collected to calculate anthropometric indices. Women form Vietnam were less satisfied with their appearance than were their Polish peers, but Vietnamese showed a lower level of preoccupation with being overweight and fear of obesity. Intercultural differences indicate that Vietnamese women show greater intensities for psychological variables, connected with restrictive and bulimic eating behaviors, verified in the research model: low self-esteem, personal alienation, interpersonal insecurity, interpersonal alienation, emotional dysregulation, interoceptive deficits, perfectionism and asceticism, and anxiety.

Confidence in one-self and confidence in one's own body: The revival of an old paradigm for anorexia nervosa

Impaired interoceptive function represents an important variable in the psychopathology of anorexia nervosa (AN) and is thought to be influenced by maladaptive schemas grounded on early intimate interactions. However, the role of the different psychological processes involved in the interoceptive function has been poorly assessed in AN. We aimed to investigate the associations between adult insecure attachment, interoceptive processes, and psychopathology. One hundred and fifty participants with AN completed self-report questionnaires: the Multidimensional Assessment of Interoceptive Awareness, which measures interoception dimensions; the Attachment Style Questionnaire, assessing adult attachment styles, and the Eating Disorder Inventory-2, exploring eating-related core symptoms. Pearson's correlations were employed to assess the relationships between MAIA and EDI-2 subscores. Structural equation models (SEM) were performed to investigate the relationships between insecure attachment dimensions, interoception, and AN core symptoms as latent variables. Body listening, self-regulating, and trusting were interoceptive dimensions associated with eating psychopathology. As confirmed by an exploratory factor analysis, these interoceptive dimensions are included in a latent variable which points to "confidence" in body sensations. SEM showed that insecure, in particular anxious, attachment predicts body "confidence" and, in turn, AN core symptoms. Confidence in body sensations as a trustworthy source of knowledge represents the specific interoceptive dimension associated with psychopathology in AN. In accordance with Bruch's model of AN, insecure attachment patterns may promote a need to validate inner experiences by external sources conferring vulnerability to symptomatology. These psychopathological pathways could be addressed in clinical interventions.

Using bodily postures in the treatment of anorexia nervosa: Effects of power posing on interoception and affective states

OBJECTIVE

Power posing involves the adoption of an expansive bodily posture. This study examined whether power posing could benefit individuals with anorexia nervosa (AN) and women with normal weight in regards to interoceptive ability and affective states.

METHOD

Participants included 50 inpatients and outpatients with AN as well as 51 normal-weight women. Interoceptive accuracy (IAcc), measured by the heartbeat tracking task and interoceptive sensibility (IS), measured by confidence ratings, were assessed at baseline, after a single power posing session and after 1 week of daily training. Also, the short-term effects of power posing on subjective feelings of dominance, pleasantness, and arousal were investigated.

RESULTS

Both groups increased in their IAcc after one power posing session. Also, there was a significant main effect of time on feelings of dominance and pleasantness in the short-term. Women with AN displayed lower levels of IS, dominance, and pleasantness as well as higher levels of arousal than women without AN.

DISCUSSION

These findings suggest that power posing has the potential to increase IAcc, subjective feelings of power and pleasant affect in the short-term. Further research should investigate which mechanisms foster the effectiveness of this intervention to tailor it to the needs of women with AN.

Reduced Environmental Stimulation in Anorexia Nervosa: An Early-Phase Clinical Trial

Reduced Environmental Stimulation Therapy (REST) alters the balance of sensory input to the nervous system by systematically attenuating sensory signals from visual, auditory, thermal, tactile, vestibular, and proprioceptive channels. Previous research from our group has shown that REST via floatation acutely reduces anxiety and blood pressure (BP) while simultaneously heightening interoceptive awareness in clinically anxious populations. Anorexia nervosa (AN) is an eating disorder characterized by elevated anxiety, distorted body representation, and abnormal interoception, raising the question of whether REST might positively impact these symptoms. However, this approach has never been studied in eating disorders, and it is unknown whether exposure to floatation REST might worsen AN symptoms. To examine these possibilities, we conducted an open-label study to investigate the safety and tolerability of REST in AN. We also explored the acute impact of REST on BP, affective symptoms, body image disturbance, and interoception. Twenty-one partially weight-restored AN outpatients completed a protocol involving four sequential sessions of REST: reclining in a zero-gravity chair, floating in an open pool, and two sessions of floating in an enclosed pool. All sessions were 90 min, approximately 1 week apart. We measured orthostatic BP before and immediately after each session (primary outcome), in addition to collecting BP readings every 10 min during the session using a wireless waterproof system as a secondary outcome measure. Each participant's affective state, awareness of interoceptive sensations, and body image were assessed before and after every session (exploratory outcomes). There was no evidence of orthostatic hypotension following floating, and no adverse events (primary outcome). Secondary analyses revealed that REST induced statistically significant reductions in BP (p < 0.001; Cohen's d, 0.2-0.5), anxiety (p < 0.001; Cohen's d, >1) and negative affect (p < 0.01; Cohen's d, >0.5), heightened awareness of cardiorespiratory (p < 0.01; Cohen's d, 0.2-0.5) but not gastrointestinal sensations, and reduced body image dissatisfaction (p < 0.001; Cohen's d, >0.5). The findings from this initial trial suggest that individuals with AN can safely tolerate the physical effects of REST via floatation. Future randomized controlled trials will need to investigate whether these initial observations of improved anxiety, interoception, and body image disturbance occur in acutely ill AN populations.

Clinical Trial Registration

ClinicalTrials.gov; Identifier: NCT02801084 (April 01, 2016).