Stress-induced laboratory eating behavior in obese women with binge eating disorder

Characterization of adults concerning the use of a hypothetical mHealth application addressing stress-overeating: an online survey

BACKGROUND

About 40% of people respond to stress by consuming more unhealthy foods. This behavior is associated with increased energy intake and the risk of obesity. As mobile health (mHealth) applications (apps) have been shown to be an easy-to-use intervention tool, the characterization of potential app users is necessary to develop target group-specific apps and to increase adherence rates.

METHODS

This cross-sectional online survey was conducted in the spring of 2021 in Germany. Sociodemographic data and data on personality (Big Five Inventory, BFI-10), stress-eating (Salzburg Stress Eating Scale, SSES), and technology behavior (Personal Innovativeness in the Domain of Information Technology, PIIT; Technology Acceptance Model 3, TAM 3) were collected.

RESULTS

The analysis included 1228 participants (80.6% female, mean age: 31.4 ± 12.8 years, mean body mass index (BMI): 23.4 ± 4.3 kg/m2). Based on the TAM score, 33.3% (409/1228) of the participants had a high intention to use a hypothetical mHealth app to avoid stress-overeating. These persons are characterized by a higher BMI (24.02 ± 4.47 kg/m2, p < 0.001), by being stress-overeaters (217/409, 53.1%), by the personality trait "neuroticism" (p < 0.001), by having specific eating reasons (all p < 0.01), and by showing a higher willingness to adopt new technologies (p < 0.001).

CONCLUSION

This study suggests that individuals who are prone to stress-overeating are highly interested in adopting an mHealth app as support. Participants with a high intention to use an mHealth app seem to have a general affinity towards new technology (PIIT) and appear to be more insecure with conflicting motives regarding their diet.

TRIAL REGISTRATION

This survey was registered in the German Clinical Trials Register (Registration number: DRKS00023984).

The efficacy of a transdiagnostic emotion regulation skills training in the treatment of binge-eating disorder-Results from a randomized controlled trial

OBJECTIVES

Deficits in emotion regulation (ER) have been shown to be associated with binge-eating disorder (BED). To further clarify the causal nature of this association, we tested whether systematically enhancing ER skills would reduce symptoms of BED.

METHODS

We randomly allocated N = 101 individuals meeting the criteria for BED to a transdiagnostic ER skills training or to a waitlist control condition (WLC). Primary outcome was the reduction in binges during the treatment-vs.-waiting period as assessed with the Eating Disorder Examination (EDE) interview.

RESULTS

Mixed-model ANOVAs indicated that the average pre-to-post decrease in binges assessed with the EDE was significantly greater in the ER skills training condition than in the WLC (d = 0.66). These effects were stable over the 6-month follow-up period (d = 0.72). Remission rates at post/follow-up were 34.4/45.0% in the skills training and 7.5/20.0% in the WLC. Additionally, we found a greater reduction in general eating disorder psychopathology, of food consumption in a bogus taste test and of depression in the ER skills training condition. Moreover, the greater reduction in binge-eating episodes in the training condition was (partially) mediated by a greater increase in ER skills.

CONCLUSIONS

The findings provide further support for the assumed importance of deficits in ER as a maintaining factor and, hence, as a target in the treatment of BED. As ER skills trainings have been shown to also reduce other kinds of psychopathology, they might be considered a promising transdiagnostic add-on component to disorder-specific interventions.

Sensor technology in eating disorders research: A systematic review

OBJECTIVE

Sensor technologies offer exciting potential to objectively measure psychopathological correlates of eating pathology and eating disorder (ED) research utilizing sensors has rapidly proliferated in the past several years. The aims of the present review are: (1) characterize the types of sensors that have been utilized in ED research, (2) identify the psychopathological factors relevant to EDs that have been assessed using sensors, (3) describe the data supporting the validity and reliability of these sensors, (4) discuss limitations associated with these sensors, and (5) identify gaps that persist within the ED literature with regard to use of sensor technologies.

METHOD

A systematic search was conducted of PubMed, PsycINFO, Web of Science, ProQuest, and "gray" literature sources. Eligible publications were empirical studies that utilized sensors to measure at least one psychological variable among clinical ED populations.

RESULTS

Sensors have been utilized with ED samples to measure eating behaviors, physical activity, sleep, autonomic nervous system activity, eyeblink startle response, visual attention, and visual-haptic object integration. The reliability and validity of these sensors varies widely and there are a number of significant gaps that remain in the literature with regard to the types of sensors utilized, context in which sensors have been used, and populations studied.

DISCUSSION

The existing literature utilizing sensors within ED research largely support the feasibility and acceptability of these tools. Sensors should continue to be utilized within the field, with a specific focus on examining the reliability and validity of these tools within ED samples and increasing the diversity of samples studied.

PUBLIC SIGNIFICANCE STATEMENT

Sensor technologies, such as those included in modern smartwatches, offer new opportunities to measure factors that may maintain or contribute to symptoms of eating disorders. This article describes the types of sensors that have been used in eating disorders research, challenges that may arise in using these sensors, and discusses new applications of these sensors that may be pursued in future research.

Volume and Connectivity Differences in Brain Networks Associated with Cognitive Constructs of Binge Eating

Bulimia nervosa (BN) and binge eating disorder (BED) are characterized by episodes of eating large amounts of food while experiencing a loss of control. Recent studies suggest that the underlying causes of BN/BED consist of a complex system of environmental cues, atypical processing of food stimuli, altered behavioral responding, and structural/functional brain differences compared with healthy controls (HC). In this narrative review, we provide an integrative account of the brain networks associated with the three cognitive constructs most integral to BN and BED, namely increased reward sensitivity, decreased cognitive control, and altered negative affect and stress responding. We show altered activity in BED/BN within several brain networks, specifically in the striatum, insula, prefrontal cortex (PFC) and orbitofrontal cortex (OFC), and cingulate gyrus. Numerous key nodes in these networks also differ in volume and connectivity compared with HC. We provide suggestions for how this integration may guide future research into these brain networks and cognitive constructs.

(Mouse cursor)-Tracking food decisions in binge eating disorder reveals preference for high-energy foods and a role of BMI

Binge Eating Disorder (BED) has been associated with deficits in cognitive control and decision-making. Yet, no study has yet investigated the characteristics of food choice and the involved choice conflict in this disorder. In the present study individuals with BED (N = 22) and without BED (N = 61), with a body mass index (BMI) between 21 and 44 completed 153 binary food decisions among foods varying in palatability and energy density. To assess conflict during choice we recorded computer mouse paths and reaction times. Subsequently, participants rated all foods on liking and energy content. Finally, participants completed a bogus taste test with the same foods to measure actual consumption. Predictors were modelled continuously using Bayesian mixed-effects modelling. Individuals with BED liked foods with higher energy content more and chose them more often in the choice task. Yet, actual consumption in the taste test did not differ between groups, neither regarding total consumption, nor of foods with higher energy. Mouse cursor-tracking revealed that control participants with higher BMIs showed more choice conflict than those with lower BMIs. This pattern was reversed in those with BED. The high-energy preference in ratings and food choice represent the first evidence in a controlled laboratory context for disorder-congruent food choice in BED. The fact that this was not reflected in actual consumption might have methodological implications for measuring laboratory eating behaviour. Mouse cursor-tracking gave further insights into choice processes and showed a less conflicted food choice in those with BED with higher BMI compared to those with lower BMI.

A review of sex differences in the mechanisms and drivers of overeating

Disordered eating is often associated with marked psychological and emotional distress, and severe adverse impact on quality of life. Several factors can influence eating behavior and drive food consumption in excess of energy requirements for homeostasis. It is well established that stress and negative affect contribute to the aetiology of eating disorders and weight gain, and there is substantial evidence suggesting sex differences in sub-clinical and clinical types of overeating. This review will examine how negative affect and stress shape eating behaviors, and how the relationship between the physiological, endocrine, and neural responses to stress and eating behaviors differs between men and women. We will examine several drivers of overeating and explore possible mechanisms underlying sex differences in eating behavior.

Effects of stress on chewing and food intake in patients with anorexia nervosa

OBJECTIVE

The present study investigates the impact of psychosocial stress on chewing and eating behavior in patients with anorexia nervosa (P_AN ).

METHOD

The eating and chewing behavior of P_AN were examined in a standardized setting by means of a chewing sensor. These procedures encompassed n = 19 P_AN , age, and gender matched to n = 19 healthy controls (HC). Food intake and chewing frequency were assessed in two experimental conditions: rest versus stress (via Trier Social Stress Test). To verify stress induction, two appraisal scales were employed. In addition, chronic stress, psychological distress and eating disorder symptoms were assessed.

RESULTS

In terms of food intake and chewing frequency, the results of the 2x2 ANOVA demonstrated a significant effect of condition and group. During stress, all participants demonstrated a higher chewing frequency and a decreased ingestion. In general, patients ate less at a lower chewing frequency (vs. HC). However, sample specific analyses demonstrated that the eating and chewing behavior of P_AN remained unchanged regardless of the condition, except for their drinking. Food choices were comparable between the groups, but appetite values significantly differed.

DISCUSSION

The increase in chewing frequency in all participants during stress suggests that chewing might impact affect regulation, however, not specifically in P_AN . Future research should clarify to what extent the normalization of chewing behavior could ameliorate ED-symptoms (incl. food intake) in P_AN . The application of a chewing sensor could support this aim and future interventions.

Breaking It Down: Investigation of Binge Eating Components in Animal Models to Enhance Translation

Binge eating (BE) is a core eating disorder behavior that is present across nearly all eating disorder diagnoses (e. g., bulimia nervosa, binge eating disorder, anorexia nervosa binge/purge subtype), and is also widely present in the general population. Despite the prevalence of BE, limited treatment options exist and there are often high rates of relapse after treatment. There is evidence showing that genetic factors contribute to the heritability of BE and support for biological contributions to BE. However, more work is needed to fully understand neurobiological mechanisms underlying BE. One approach to target this problem is to separate BE into its distinct clinical components that can be more easily modeled using pre-clinical approaches. To date, a variety of animal models for BE have been used in pre-clinical studies; but there have been challenges translating this work to human BE. Here, we review these pre-clinical approaches by breaking them down into three clinically-significant component parts (1) consumption of a large amount of food; (2) food consumption within a short period of time; and (3) loss of control over eating. We propose that this rubric identifies the most frequently used and effective ways to model components of BE behavior using pre-clinical approaches with the strongest clinical relevance. Finally, we discuss how current pre-clinical models have been integrated with techniques using targeted neurobiological approaches and propose ways to improve translation of pre-clinical work to human investigations of BE that could enhance our understanding of BE behavior.

Identifying stress-related eating in behavioural research: A review

Stress is a commonly reported precipitant of overeating. Understanding the relationship between stress and food intake is important, particularly in view of the increasing prevalence of obesity. The purpose of this review is to examine how stress-related eating has been defined and measured in the literature to date. There are no established diagnostic criteria or gold standards for quantification of stress-related eating. Questionnaires relying on the accuracy of self-report are the mainstay of identifying people who tend to eat in response to stress and emotions. There is a paucity of clinical research linking objective measurements of stress and appetite with self-reported eating behaviour. Limitations of the methodological approaches used and the heterogeneity between studies leave significant knowledge gaps in our understanding of the mechanism of stress related eating, and how best to identify it. These issues are discussed, and areas for further research are explored.

A Functional Near-Infrared Spectroscopy Study on the Cortical Haemodynamic Responses During the Maastricht Acute Stress Test

In order to better understand stress responses, neuroimaging studies have investigated the underlying neural correlates of stress. Amongst other brain regions, they highlight the involvement of the prefrontal cortex. The aim of the present study was to explore haemodynamic changes in the prefrontal cortex during the Maastricht Acute Stress Test (MAST) using mobile functional Near-Infrared Spectroscopy (fNIRS), examining the stress response in an ecological environment. The MAST includes a challenging mental arithmic task and a physically stressful ice-water task. In a between-subject design, participants either performed the MAST or a non-stress control condition. FNIRS data were recorded throughout the test. Additionally, subjective stress ratings, heart rate and salivary cortisol were evaluated, confirming a successful stress induction. The fNIRS data indicated significantly increased neural activity of brain regions of the dorsolateral prefrontal cortex (dlPFC) and the orbitofrontal cortex (OFC) in response to the MAST, compared to the control condition. Furthermore, the mental arithmetic task indicated an increase in neural activity in brain regions of the dlPFC and OFC; whereas the physically stressful hand immersion task indicated a lateral decrease of neural activity in the left dlPFC. The study highlights the potential use of mobile fNIRS in clinical and applied (stress) research.

Testing virtual reality-based cue-exposure software: Which cue-elicited responses best discriminate between patients with eating disorders and healthy controls?

PURPOSE

Virtual reality (VR) technologies have been proposed as a new tool able to improve on in vivo exposure in patients with eating disorders. This study assessed the validity of a VR-based software for cue exposure therapy (CET) in people with bulimia nervosa (BN) and binge eating disorder (BED).

METHODS

Fifty eight outpatients (33 BN and 25 BED) and 135 healthy participants were exposed to 10 craved virtual foods and a neutral cue in four experimental virtual environments (kitchen, dining room, bedroom, and cafeteria). After exposure to each VR scenario, food craving and anxiety were assessed. The frequency/severity of episodes of uncontrollable overeating was also assessed and body mass index was measured prior to the exposure.

RESULTS

In both groups, craving and anxiety responses when exposed to the food-related virtual environments were significantly higher than in the neutral-cue virtual environment. However, craving and anxiety levels were higher in the clinical group. Furthermore, cue-elicited anxiety was better at discriminating between clinical and healthy groups than cue-elicited craving.

CONCLUSIONS

This study provides evidence of the ability of food-related VR environments to provoke food craving and anxiety responses in BN and BED patients and highlights the need to consider both responses during treatment. The results support the use of VR-CET in the treatment of eating disorder patients characterized by binge-eating and people with high bulimic symptoms.

Negative affect, dietary restriction, and food choice in bulimia nervosa

OBJECTIVE

Negative affect is a precipitant for binge eating in bulimia nervosa (BN). The purpose of the current study was to examine the effect of negative affect on food choices on a more granular level among individuals with BN using a computerized Food Choice Task.

METHOD

Individuals with BN (n = 25) and healthy controls (HC, n = 21) participated in a computerized Food Choice Task following negative and neutral affect inductions, across two study sessions. During the task participants rated high and low-fat food items for Healthiness and Tastiness. Individuals then made a series of choices between a neutral-rated food and high and low-fat foods and were then given a snack based upon these choices.

RESULTS

Overall negative affect score increased significantly for both the BN and HC groups following the negative affect induction. The group of individuals with BN, relative to the HC group, was less likely to choose high-fat foods (z = -2.763, p = 0.006), and these choices were not impacted by affect condition. Health ratings influenced food choices significantly more among individuals with BN than HC (z = 2.55, p = 0.01).

DISCUSSION

Induction of negative affect was successful, yet was not related to an increase in proportion of high-fat food choices in the group of individuals with BN. The Food Choice Task captured dietary restriction in individuals with BN and results highlight the utility of this task as a probe to examine how the values of healthiness and tastiness impact food choice in individuals with BN.

Body compassion safeguards against the impact of major life events on binge eating

Body compassion is a fresh construct that incorporates two multidimensional concepts: body image and self-compassion. Although self-compassion has revealed a protective role against body image and eating-related problems (e.g., binge eating), the study of this specific compassionate competence focused on body image is still largely unexplored. The present study aimed to test two moderation models which hypothesized that body compassion moderates the impacts of (i) the cumulative number and (ii) negative appraisal of major life events on binge eating behaviours, in a sample of 458 women from the Portuguese general population. Results showed that body compassion was negatively associated with major life events and binge eating. Moderation analysis results demonstrated the moderator effect of body compassion on the relationship between major life events (both cumulative number and negative appraisal) and binge eating, accounting for 34% and 33% of the variance of binge eating, respectively. The moderator effect of body compassion was confirmed to low to medium levels of body compassion and, overall, results seem to suggest that, for the same levels of major life events (in number or negative appraisal), women who present higher body compassion present less binge eating symptoms. Although these data are preliminary and need support from a longitudinal design research, current findings appear to be promising by suggesting the relevance of promoting body compassion in prevention and treatment programs for disordered eating attitudes and behaviours.

Emotion Regulation in Binge Eating Disorder: A Review

The purpose of the present review is to provide a summary of the research findings on emotion regulation in Binge Eating Disorder (BED). Negative emotions and maladaptive emotion regulation strategies play a role in the onset and maintenance of binge eating in BED. Anger and sadness, along with negative emotions related to interpersonal experiences (i.e., disappointment, being hurt or loneliness), seem to be particularly relevant. Individuals with BED have a tendency to suppress and ruminate on their unwanted emotions, which leads to increased psychopathological thoughts and symptoms. Compared to healthy controls, they use adaptive strategies, such as reappraisal, less frequently. Evidence concerning the causal relation between negative affect and binge eating is inconclusive and still very limited. While experimental studies in a laboratory setting lack ecological validity, ecological momentary assessment studies offer more promise at unraveling the causal relationship between emotions and binge eating. Increases in negative affect are found to be antecedents of binge eating in BED. However, there seems to be less support for the possibility that binge eating serves as a means to alleviate negative affect. Finally, BED seems to be related to other forms of maladaptive emotion regulation strategies, such as substance abuse and self-harm.

Stress, overeating, and obesity: Insights from human studies and preclinical models

Eating disorders and obesity have become predominant in human society. Their association to modern lifestyle, encompassing calorie-rich diets, psychological stress, and comorbidity with major diseases are well documented. Unfortunately the biological basis remains elusive and the pharmacological treatment inadequate, in part due to the limited availability of valid animal models. Human research on binge eating disorder (BED) proves a strong link between stress exposure and bingeing: state-levels of stress and negative affect are linked to binge eating in individuals with BED both in laboratory settings and the natural environment. Similarly, classical animal models of BED reveal an association between acute exposure to stressors and binging but they are often associated with unchanged or decreased body weight, thus reflecting a negative energy balance, which is uncommon in humans where most commonly BED is associated with excessive or unstable body weight gain. Recent mouse models of subordination stress induce spontaneous binging and hyperphagia, altogether more closely mimicking the behavioral and metabolic features of human BED. Therefore the translational relevance of subordination stress models could facilitate the identification of the neurobiological basis of BED and obesity-associated disease and inform on the development of innovative therapies.

An experimental analysis of the affect regulation model of binge eating

There is research suggesting that binge eating may serve an affect regulation function. However, experimental evidence supporting this model in adults is sparse and studies have been mixed regarding whether negative affect impacts objective energy intake. This study examined the impact of a real-time interpersonal stressor on laboratory test meal intake between individuals endorsing recent objective binge eating (≥1×/week) and those denying disordered eating. Generalized linear modeling was used to compare individuals with recent binge eating (BE group; n = 52) to those denying recent eating pathology (HC group; n = 51) on test meal intake following a stressor (stressful condition) or neutral stimulus (non-stressful condition). Moderated mediation analyses were used to examine whether negative affect mediated the impact of condition on intake differently between BE and HC groups. The BE group did not have significantly higher energy intake than the HC group in the stressful verses non-stressful condition. However, the BE group was more likely to engage in extreme intake (i.e., over- or under-consumption) than the HC group in the stressful versus non-stressful condition (p = 0.02). Changes in negative affect did not significantly mediate the relationship between condition and intake extremes for the BE group. The results indicate that both over- and under-consumption are triggered by stress among individuals with recent binge eating. Continued research investigating both binge eating and restriction as a means of affect regulation in binge-eating samples is encouraged.

Acute Stressors Reduce Neural Inhibition to Food Cues and Increase Eating Among Binge Eating Disorder Symptomatic Women

Stressors can trigger binge-eating but researchers have yet to consider their effects on both neural responses to food cues and food consumption among those at risk. In this experiment, we examined the impact of acute stressors on neural activation to food images and subsequent food consumption within binge-eating disorder (BED) and non-eating disordered control groups. Eighteen women meeting DSM-IV BED criteria and 26 women serving as non-eating disordered controls were randomly assigned to unpleasant stressor (painful cold pressor test (CPT) followed by negative performance feedback) or less unpleasant stressor (non-painful sensory discrimination task followed by positive performance feedback) conditions. Subsequently, they were scanned with functional magnetic resonance imaging (fMRI) while viewing food and neutral images. After the scans, participants completed a self-report battery in an environment conducive to snacking. During exposure to food images, BED-symptomatic women in the unpleasant stressor condition reported more liking of high calorie food images and showed less activation in one inhibitory area, the hippocampus, compared to controls in this condition. BED-symptomatic women exposed to unpleasant stressors also consumed more chocolate than any other group during the post-scan questionnaire completion. Crucially, reduced hippocampal activation to high calorie food images predicted more chocolate consumption following fMRI scans within the entire sample. This experiment provides initial evidence suggesting unpleasant acute stressors contribute to reduced inhibitory region responsiveness in relation to external food cues and later food consumption among BED-symptomatic women.

The relation of anxiety, depression, and stress to binge eating behavior

This study aimed to extend the literature by examining several psychological factors (i.e. depression, anxiety, and stress) in relation to binge eating. Data were collected via online surveys from a community sample of men and women of diverse backgrounds. The main study hypotheses were supported, indicating a unique relation between anxiety and binge eating, and between stress and binge eating, independent of the impact of depression. Gender differences are discussed. The results of this study suggest a need for a more detailed examination of negative affect in binge eating. Furthermore, the role of anxiety may be important for future research.

The neurobiological basis of binge-eating disorder

Relatively little is known about the neuropathophysiology of binge-eating disorder (BED). Here, the evidence from neuroimaging, neurocognitive, genetics, and animal studies are reviewed to synthesize our current understanding of the pathophysiology of BED. Binge-eating disorder may be conceptualized as an impulsive/compulsive disorder, with altered reward sensitivity and food-related attentional biases. Neuroimaging studies suggest there are corticostriatal circuitry alterations in BED similar to those observed in substance abuse, including altered function of prefrontal, insular, and orbitofrontal cortices and the striatum. Human genetics and animal studies suggest that there are changes in neurotransmitter networks, including dopaminergic and opioidergic systems, associated with binge-eating behaviors. Overall, the current evidence suggests that BED may be related to maladaptation of the corticostriatal circuitry regulating motivation and impulse control similar to that found in other impulsive/compulsive disorders. Further studies are needed to understand the genetics of BED and how neurotransmitter activity and neurocircuitry function are altered in BED and how pharmacotherapies may influence these systems to reduce BED symptoms.

The association between emotions and eating behaviour in an obese population with binge eating disorder

There is utility in understanding the antecedents of binge eating (BE), with a view to explaining poorer weight loss treatment responses in this subgroup. A systematic review was completed according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines with the aim of exploring associations between emotions and eating behaviour in a population affected by obesity and binge eating disorder (BED). A comprehensive literature search of four electronic databases (2004-2014) yielded 15 studies for inclusion. Included studies performed poorly on data quality analysis with respect to controlling for confounding variables, and sample size. Included papers largely focused on negative emotions as antecedents of BE; depression was consistently associated with a BED-obese classification and BE. Negative mood, sadness, tension and instability of emotions were found to be antecedents of BE in an adult BED-obese sample. However, findings were mixed regarding the role of stress, anger and positive emotions within the BED-obese population. Recommendations are presented for the identification of BED, and ecologically valid experimental designs that further understanding of the complex and varied emotions that associate with BE. The implications of these and other limitations for both researchers and practitioners are discussed. The paper concludes with recommendations for future research alongside suggestions for practitioners. © 2015 World Obesity.

Negative Social Evaluative Fears Produce Social Anxiety, Food Intake, and Body Dissatisfaction: Evidence of Similar Mechanisms through Different Pathways

Social anxiety and eating disorders are highly comorbid, suggesting there are shared vulnerabilities that underlie the development of these disorders. Two proposed vulnerabilities are fear of negative evaluation and social appearance anxiety (i.e., fear of negative evaluation regarding one's appearance). In the current experimental study (N=160 women) we measured these fears: (a) through a manipulation comparing fear conditions, (b) with trait fears, and (c) state fears. Results indicated that participants in the fear of negative evaluation condition increased food consumption, whereas participants in the social appearance anxiety condition and high in trait social appearance anxiety experienced the highest amounts of body dissatisfaction. Participants in the fear of evaluation and social appearance anxiety conditions experienced elevated social anxiety. These results support the idea that negative evaluation fears are shared vulnerabilities for eating and social anxiety disorders, but that the way these variables exert their effects may lead to disorder specific behaviors.

Chewing after stress: psychosocial stress influences chewing frequency, chewing efficacy, and appetite

BACKGROUND

Psychosocial stress is accompanied by an increase in the activity of the hypothalamic-pituitary-adrenocortical (HPA)-axis and by an increase in food intake. At present, no studies have been conducted to examine the impact of a potent laboratory stress test on the chewing frequency.

METHODS

Thirty-one healthy participants (14 females, mean age 27.13) were compared after they had fulfilled the protocol of a standardized psychosocial stress test, the Trier Social Stress Test (TSST), and after a resting condition of silent reading in reference to their chewing frequency, chewing efficacy, food intake, and eating preferences. As part of the design free salivary cortisol levels and heart rate variability were measured repeatedly before and after the TSST and the resting condition.

RESULTS

After the TSST, the participants exhibited a significantly higher mean chewing frequency than after the resting condition (F(2,60)=3.600, p=.035, η(2)=.107). The testing condition had no influence on the amount of food intake. Following the psychosocial stress, however, the participants reported a significantly less general appetite (Z=-3.921, p<.001) and less of an appetite for eggs (Z=-2.023, p=.043) than after their resting condition. No correlation was found between the salivary cortisol response and the chewing frequency.

CONCLUSION

The results indicated that psychosocial stress is associated with an increase in chewing frequency, as measured with a sound-based apparatus, and with a decrease in appetite.

Urinary cortisol and psychopathology in obese binge eating subjects

BACKGROUND

Investigations on the relationship between obesity, binge eating and the function of hypothalamic-pituitary-adrenal (HPA) axis have led to inconsistent results. General psychopathology affects HPA axis function. The present study aims to examine correlations between binge eating, general psychopathology and HPA axis function in obese binge eaters.

METHODS

Twenty-four hour urinary free cortisol (UFC/24 h) was measured in 71 obese binge eating women. The patients were administered psychometric tests investigating binge eating, psychopathology and clinical variables. The relationship between binge eating, psychopathology and urinary cortisol was investigated, controlling for age and BMI.

RESULTS

We found an inverse correlation between UFC/24 h and binge eating, depression, obsessive-compusive symptoms, somatization and sensitivity. In a regression model a significant inverse correlation between urinary cortisol and psychopathology was confirmed.

CONCLUSIONS

Urinary cortisol levels in obese patients with binge eating disorder show an inverse correlation with several dimensions of psychopathology which are considered to be typical of a cluster of psychiatric disorders characterized by low HPA axis function, and are very common in obese binge eating patients. If these results are confirmed, UFC/24 h might be considered a biomarker of psychopathology in obese binge eaters.

Pilotstudie zur Effektivität eines Emotionsregulationstrainings bei Frauen mit Binge-Eating-Störung

Negative Emotionen sind ein häufiger Auslöser von Essanfällen bei Personen mit Binge-Eating-Störung (BES). Erste Untersuchungen haben gezeigt, dass Defizite in der Emotionsregulation (ER) den Zusammenhang von negativen Emotionen und Essanfällen mediieren. Vor diesem Hintergrund erhielten im Rahmen einer Pilotstudie 14 Frauen mit BES ein ER-Training in der Gruppe. Indikatoren für die Effektivität des Trainings waren Anzahl der Episoden und Tage mit objektiven Essanfällen, Körperunzufriedenheit, sowie Depressivität vor Studienbeginn (T0), nach 8 Wochen Wartezeit (T1) und nach dem 8-wöchigen ER-Training (T2). Während es keine Veränderungen von T0 zu T1 gab, zeigte sich eine signifikante Reduktion der Symptomatik in allen erhobenen Variablen von T1 zu T2. Die Ergebnisse der Pilotstudie unterstützen die Relevanz der ER bezüglich der Reduktion von Essanfällen und damit die Notwendigkeit gut implementierter Therapiestudien, die die Effektivität von ER-Trainings in der Veränderung der Psychopathologie der BES untersuchen. Zudem sind weitere Studien, die die Rolle der ER bei der Aufrechterhaltung der BES klären, notwendig.

Cravings and food consumption in Binge Eating Disorder

The purpose of this study was to extend existing work that examines the role of cravings in Binge Eating Disorder (BED). The current study uses a case-control design to establish a relationship between cravings and food exposure, and between cravings and food consumption in individuals diagnosed with BED. Twenty-nine females with BED, 40 obese controls, and 50 normal-weight controls were first presented with a neutral cue and completed a food-craving measure. They were then presented with their favourite snack food and completed the craving measure again, after which they were allowed to consume the food. The BED group had significantly higher scores for pre- and post-craving measures, and consumed more food compared to the controls. There was, however, no significant interaction between group and craving scores. Results also showed a positive correlation between food consumption and cravings scores both before and after food exposure for individuals with BED. The findings suggest that the level of cravings prior to food exposure may be sufficient to predict overeating in BED and that treatment may want to target this as a defining feature that differentiates individuals with BED from those who do not binge eat.

[Triggers of bulimia and compulsion attacks: validation of the "Start" questionnaire]

AIM

There are few published studies on the triggers of binge eating in anorexia nervosa of binge/purging subtype (BPAN), bulimia nervosa (BN) and binge eating disorder (BED).

PATIENTS AND METHODS

We validated in 29 patients (10 BPAN, 10 BN and 9 BED) the perspicuity, the clarity and the intra- (doubles) and inter- (test-retest) reproducibility of a 24-item Start questionnaire on the triggers of binge eating. Then the Start questionnaire was administered to 176 patients (65 BPAN, 62 BN and 59 BED patients) being 27.5+9.1 yr old, having 15+9 binge eating (BE) episodes/week, with a mean binge duration of 1 hr 36min (+ 38min)/day.

RESULTS

BE episodes occurred mainly during the second part of the day: afternoon after work (67% of the patients), "tea" time (55%), evening after dinner (42%) and at night (22%). The principal place for BE episodes was at home (96%). The BED patients avoided binges at the parents' home (89%) more often than the BPAN (62%, P<0.02). The binges occurred mainly in the living room (44%), in the kitchen (43%), and less in the bedroom (31%). Hunger pangs seemed to be a trigger of binges in 31% of the patients, and a stronger trigger in BED (42%) than in the BPAN and BN patients (24%; P=0.04). Binge eating episodes could occur despite a high satiety level (just after lunch or dinner) in 29% of the BN and in 16% of the BED patients (P<0.02). Concerning food, the major triggers were high energy-density food (77%) and comfort food (60%), such as chocolate, cakes, bread and pasta. The food consumed for binge episodes (in-binge food) was more often a strong trigger than the other food (not used for binges): olfaction (19% versus 10%), sight (52% versus 25%) and placing in the mouth (71% versus 26%; P<0.02 for all, in the 3 groups). Being tired could be a strong trigger in 37% of the patients, but "being aroused" in the other 38 % of the patients. Stressful events (65%), anxiety (74%), "being under pressure" or irritated (51% and 55%) were of course major triggers in a majority of the patients, as well as sadness (61%), feeling of powerlessness (62%), inefficiency (73%) and depressive state (71%). Flashback from traumatism (sexual trauma in 17% of the patients) was a strong trigger of binges more often in BPAN and BED (44%) than in BN (23%; P<0.05). The binge eating was painful (and "not at all a pleasure") in 69% of the patients, but could also be a relaxing behavior in 31% of the patients, more often in the BED (43%) than in the BPAN patients (20%; P<0.05). The binge eating behavior was quoted as obsessive in 63% of BPAN, 92% of BN and only 34% of BED patients (P<0.001). The patients said that they were unable to avoid the binge (76% of the patients), more often in BPAN and BN than in BED patients (P<0.01). As a whole, 62% of BPAN, 89% of BN and only 4 % of BED patients (P<0.05) were unable to avoid purging (vomiting). In 12% of the cases, there was a pleasure felt when binging. For the other patients, shame, filth and incapacity were the feelings related to binges in 58% of the BPAN, 45% of BN and 43% of BED patients (P<0.04). The global score of addiction (zero=not addicted, 10=very addicted) was 8.56+1.2 in BPAN, 8.42+1.5 in BN and 6.74+1.1 in BED patients (NS between BPAN and BN; P<0.01 between BPAN and BN on the one hand and BED on the other).

CONCLUSION

The present study has demonstrated the usefulness of the Start questionnaire. It also evidences the key role of intrinsic factors, both metabolic and emotional, as strong triggers for binge eating episodes in BPAN, BN and BED. It has also demonstrated the role of environmental determinants.

Social appearance anxiety, perfectionism, and fear of negative evaluation: distinct or shared risk factors for social anxiety and eating disorders?

Social anxiety and eating disorders are highly comorbid. Social appearance anxiety (i.e., fear of negative evaluation of one's appearance), general fear of negative evaluation, and perfectionism have each been proposed as risk factors for both social anxiety disorder and the eating disorders. However, no research to date has examined all three factors simultaneously. Using structural equation modeling in two diverse samples (N=236; N=136) we tested a model in which each of these risk factors were uniquely associated with social anxiety and eating disorder symptoms. We found support for social appearance anxiety as a shared risk factor between social anxiety and eating disorder symptoms, whereas fear of negative evaluation was a risk factor only for social anxiety symptoms. Despite significant zero-order relationships, two facets of perfectionism (high standards and maladaptive perfectionism) did not emerge as a risk factor for either disorder when all constructs were considered. These results were maintained when gender, body mass index, trait negative affect, and depression were included in the model. It is possible that treating negative appearance evaluation fears may reduce both eating disorder and social anxiety symptoms.

Academic examination stress increases disordered eating symptomatology in female university students

BACKGROUND

It is well documented that stress and anxiety can affect eating behaviour and food intake in humans. The purpose of the current study was to explore the possible effect of academic examination stress on disordered eating attitudes, emotional eating, restraint eating, body image, anxiety levels and self-esteem in a group of female university students. The interrelationships of the above parameters were also examined.

METHODS

Sixty Greek female university students, 18-25 years old, have been recruited and completed, on two separate occasions: a) during an examination stress period, and b) during a control period, the following questionnaires: the Eating Attitudes Test (EAT-26), the Dutch Eating Behavior Questionnaire (DEBQ), the State-Trait Anxiety Inventory (STAI), the Rosenberg Self- Esteem Scale, the Body Image Pictorial Instrument Scale (COLLINS) and a specially designed General Background Questionnaire.

RESULTS

Subjects reported significantly higher levels of disordered eating attitudes (EAT-26, p=0.01), higher levels of anxiety (p=0.000) and lower levels of self-esteem (p=0.016) during the examination stress period compared to the control period. Disordered eating attitudes (EAT-26) were significantly positively correlated with emotional eating (p=0.04) and restrained eating (p=0.010) and negatively correlated with levels of self-esteem (p=0.05) and perceived desired body image (p=0.008) during the exam stress period. Finally, EAT-26 was significantly positively correlated with levels of anxiety in both study periods.

CONCLUSION

Academic examination stress seems to increase disordered eating symptomatology in female university students and is associated with lower levels of self-esteem, an important finding which warrants further investigation.

The relationships between fat talk, body dissatisfaction, and drive for thinness: perceived stress as a moderator

Although body dissatisfaction and drive for thinness are commonplace in college-aged women, their relationships with fat talk and stress are understudied. This study examined (a) whether fat talk predicts body dissatisfaction and drive for thinness and (b) whether stress moderates these relationships. Results from self-report questionnaires completed by 121 female college students revealed that fat talk and perceived stress were significantly positively correlated with body dissatisfaction and drive for thinness. Although fat talk was a significant independent predictor of body dissatisfaction and drive for thinness, stress moderated these relationships such that they were stronger at lower stress levels. Although contrary to predictions, these results are logical when means are considered. Results suggest that fat talk positively predicts body dissatisfaction and drive for thinness in students with relatively lower stress levels, but does not for students under high stress because mean levels of these constructs are all already high.

No evidence of increased cortisol stress response in obese women with binge eating disorder

Increased cortisol levels after stress have been associated with excessive food intake during binges in obese women with binge eating disorder (BED). The present study tried to replicate these findings in a sample of obese women with BED compared to obese women without BED. Twenty women with a mean BMI of 37.75 kg/m² were studied. Salivary cortisol was sampled before and after a socially evaluated cold pressure test at 8 time points. Both comparison groups showed the expected cortisol increase after the stressor (p<0.03), but no significant differences between groups emerged (p=0.96). These results do not support an increased stress reactivity of HPA in BED. Instead they would favour psychological explanations of binges, focusing on diminished perception of satiety.

Obese adolescents with eating disorders: analysis of metabolic and inflammatory states

OBJECTIVE

The purpose of the present investigation was to compare the effect of interdisciplinary therapy on the physical and metabolic profiles, including body composition, insulin resistance and sensitivity as well as adiponectin and leptin concentrations, of obese adolescents with and without eating disorder symptoms.

METHODS

A total of 83 obese adolescents (28 with and 55 without eating disorder symptoms) were enrolled for 1 year of interdisciplinary weight-loss therapy (clinical, nutritional, exercise, physiotherapy and psychological). Bulimic and binge eating symptoms were measured by the Bulimic Investigatory Test, Edinburgh, and the Binge Eating Scale, respectively. Leptin and adiponectin concentrations were measured with enzyme-linked immunosorbent assay kits. Visceral and subcutaneous fat were assessed by ultrasonography.

RESULTS

Both groups demonstrated improved body mass, body mass index, body fat (%), lean mass, visceral fat, subcutaneous fat, homeostasis model assessment insulin-resistance index (HOMA-IR), quantitative insulin sensitivity check index, total cholesterol, LDL-cholesterol, VLDL, triglycerides, adiponectin and leptin concentrations after therapy. We found a positive correlation between leptin concentrations and subcutaneous fat in the control group and a negative correlation between adiponectin concentrations and HOMA-IR and fat mass (%). The prevalence of obese adolescents with eating disorders was reduced by 89% after 1 year of interdisciplinary therapy.

CONCLUSION

The eating disorder symptoms did not impair the metabolic state during weight loss therapy of obese adolescents. Additionally, long-term interdisciplinary therapy was effective in reducing the chances of developing several co-morbidities in both groups.

Feeding and reward: perspectives from three rat models of binge eating

Research has focused on understanding how overeating can affect brain reward mechanisms and subsequent behaviors, both preclinically and in clinical research settings. This work is partly driven by the need to uncover the etiology and possible treatments for the ongoing obesity epidemic. However, overeating, or non-homeostatic feeding behavior, can occur independent of obesity. Isolating the variable of overeating from the consequence of increased body weight is of great utility, as it is well known that increased body weight or obesity can impart its own deleterious effects on physiology, neural processes, and behavior. In this review, we present data from three selected animal models of normal-weight non-homeostatic feeding behavior that have been significantly influenced by Bart Hoebel's 40+-yr career studying motivation, feeding, reinforcement, and the neural mechanisms that participate in the regulation of these processes. First, a model of sugar bingeing is described (Avena/Hoebel), in which animals with repeated, intermittent access to a sugar solution develop behaviors and brain changes that are similar to the effects of some drugs of abuse, serving as the first animal model of food addiction. Second, another model is described (Boggiano) in which a history of dieting and stress can perpetuate further binge eating of palatable and non-palatable food. In addition, a model (Boggiano) is described that allows animals to be classified as having a binge-prone vs. binge-resistant behavioral profile. Lastly, a limited access model is described (Corwin) in which non-food deprived rats with sporadic limited access to a high-fat food develop binge-type behaviors. These models are considered within the context of their effects on brain reward systems, including dopamine, the opioids, cholinergic systems, serotonin, and GABA. Collectively, the data derived from the use of these models clearly show that behavioral and neuronal consequences of bingeing on a palatable food, even when at a normal body weight, are different from those that result from simply consuming the palatable food in a non-binge manner. These findings may be important in understanding how overeating can influence behavior and brain chemistry.

Repetitive transcranial magnetic stimulation reduces cortisol concentrations in bulimic disorders

BACKGROUND

In people with bulimic eating disorders, exposure to high-calorie foods can result in increases in food craving, raised subjective stress and salivary cortisol concentrations. This cue-induced food craving can be reduced by repetitive transcranial magnetic stimulation (rTMS). We investigated whether rTMS has a similar effect on salivary cortisol concentrations, a measure of hypothalamic-pituitary-adrenal axis (HPAA) activity.

METHOD

We enrolled twenty-two female participants who took part in a double-blind randomized sham-controlled trial on the effects of rTMS on food craving. Per group, eleven participants were randomized to the real or sham rTMS condition. The intervention consisted of one session of high-frequency rTMS delivered to the left dorsolateral prefrontal cortex (DLPFC). Salivary cortisol concentrations were assessed at four time points throughout the 90-min trial. To investigate differences in post-rTMS concentrations between the real and sham rTMS groups, a random-effects model including the pre-rTMS cortisol concentrations as covariates was used.

RESULTS

Salivary cortisol concentrations following real rTMS were significantly lower compared with those following sham rTMS. In this sample, there was also a trend for real rTMS to reduce food craving more than sham rTMS.

CONCLUSIONS

These results suggest that rTMS applied to the left DLPFC alters HPAA activity in people with a bulimic disorder.

Associations of negative affect and eating behaviour in obese women with and without binge eating disorder

The present study was planned to investigate differences in psychopathological features, eating behaviour and eating habits between obese women with and without BED. It also aimed to identify specific relationships between affective symptoms and eating behaviour in obese women with BED. Eighty-four obese women were studied (40 with BED, 44 non-BED). Psychiatric comorbidities were assessed with the structured diagnostic interview for DSM-IV (SCID). Depressive symptoms were measured with the Beck Depression Inventory (BDI) and anxiety with the state-trait anxiety inventory (STAI). Eating habits (emotional and restrained eating) were assessed by the Dutch eating behaviour questionnaire (DEBQ). Food diaries were used for assessing naturalistic eating behaviour (food intake) and mood before and after food intake. BED subjects exhibited higher levels of comorbidity (in particular mood disorders, anxiety disorders and substance-related disorders), higher depressive symptoms, trait anxiety, external and emotional eating scores than non-BED subjects. Regression analyses revealed that anxiety and emotional eating were significant predictors for BED status. In the BED group, depressive symptoms were significantly related to emotional eating and food intake and negatively related to restraint. Anxiety was significantly related to emotional eating. In general, food intake significantly enhanced mood. Mood was worse on the days with self-reported binge eating episodes than on nonbinge days. These results are discussed with regard to aetiological models for BED and for BED being a distinct diagnostic category separate from obesity.