Inhibitory control pathway to disinhibited eating: A matter of perspective?

Neurocomputational mechanisms underlying differential reinforcement learning from wins and losses in obesity with and without binge eating

BACKGROUND

Binge Eating Disorder (BED) is thought of as a disorder of cognitive control but evidence regarding its neurocognitive mechanisms is inconclusive. Key limitations in prior research are a lack of consistent separation between effects of BED and obesity, and a disregard for self-report evidence suggesting that neurocognitive alterations may emerge primarily in loss- or harm-avoidance contexts.

METHODS

Addressing these gaps, this longitudinal study investigated behavioral flexibility and its underlying neuro-computational processes in reward-seeking and loss-avoidance contexts. Obese participants with BED (BED), without BED (OB), and healthy normal-weight participants (NW) (Ntotal=96) performed a probabilistic reversal learning task during functional imaging, with different blocks focused on obtaining wins or avoiding losses. They were reinvited for a 6-months follow-up.

RESULTS

Analyses informed by computational models of reinforcement learning showed that unlike BED, OB performed worse in the win than the loss condition. Computationally, this was explained by differential learning sensitivities in the win vs loss conditions between groups. In the brain, this was echoed in differential neural learning signals in the ventromedial prefrontal cortex (vmPFC) per condition. The differences were subtle, but scaled with BED symptoms, such that more severe BED symptoms were associated with increasing bias towards improved learning from wins vs losses. Across conditions, OB switched more between choice options than NW. This was reflected in diminished representation of choice certainty in the vmPFC.

CONCLUSIONS

Our study highlights the importance of distinguishing between obesity with and without BED to identify unique neuro-computational alterations underlying different styles of maladaptive eating behavior.

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.

Associations of food reinforcement and food- related inhibitory control with adiposity and weight gain in children and adolescents

Some, but not all studies have reported that, among youth with disordered eating and high weight, the relative reinforcing value of food (RRV-F, i.e., how hard a person will work for a high-energy-dense food when another reward is available) is greater, and food-related inhibitory control (i.e., ability to withhold a response to food-related stimuli) is lower, compared to peers without disordered eating or overweight. In most studies, high RRV-F and low food-related inhibitory control have been studied separately, as independent factors, with each suggested to predict excess weight and adiposity (fat mass) gain. We hypothesized that the interaction of these factors would prospectively exacerbate risk for weight and adiposity (fat mass) gain three years later in a sample of healthy youth. At baseline, RRV-F was measured using a Behavior Choice Task with the rewards being standardized servings of chocolate candies, cheese crackers, or fruit snacks. Food-related inhibitory control was determined by performance in response to food and non-food stimuli during a Food Go/No-Go task. At baseline and 3-year visits, total body adiposity was measured by dual-energy X-ray absorptiometry (DXA) and body mass index (BMI) was obtained using measured weight and height. A linear regression was conducted with 3-year adiposity as the dependent variable. RRV-F, food-related inhibitory control, and the RRV-F x food-related inhibitory control interaction as independent variables. Baseline adiposity, age, height, sex, race/ethnicity, and days between visits were included as covariates for model predicting 3-year adiposity. Baseline BMI, age, sex, race/ethnicity, and days between visits were included as covariates for model predicting 3-year BMI. One-hundred and nine youth (mean 12.4±2.7y, mean 0.50±1.02 BMIz, 30.3% with overweight/obesity, 45.9% female, 51.4% non-Hispanic White), 8-17 years at baseline, were studied. Baseline food-related inhibitory control (βunstandardized = 0.33, p = .037, 95% CI [.02, 0.64]), but not baseline RRV-F (βunstandardized = -0.003, p = .914), 95% CI [-0.05, 0.05]) was significantly associated with 3-year adiposity such that those with the poorest food-related inhibitory control (great number of commision errors) had the greatest adiposity gain. The interaction between RRV-F and food-related inhibitory control did not predict 3-year adiposity (βunstandardized = -0.07, p = .648, 95% CI [-0.39, 0.25]). The pattern of findings was the same for models examining non-food related inhibitory control. Neither baseline food-related inhibitory control (βunstandardized = 2.16, p = .256, 95% CI [-1.59, 5.92]), baseline RRV-F (βunstandardized = 0.14, p = .660, 95% CI [-0.48, 0.75]), nor their interaction (βunstandardized = -1.18, p = .547, 95% CI [-5.04, 2.69]) were significantly associated with 3-year BMI. However, non-food related inhibitory control (βunstandardized = 0.54, p = .038, 95% CI [.22, 7.15]) was significantly associated with 3-year BMI. In summary, food-related inhibitory control but not RRV-F, was associated with changes in adiposity in a sample of children and adolescents. Among generally healthy youth, food-related inhibitory control may be a more relevant risk factor than food reinforcement for adiposity gain. Additional data are needed to determine how inhibitory control and reward systems, as well as other disinhibited eating behaviors/traits, may interact to promote excess weight gain over time in youth.

Neural differences of food-specific inhibitory control in people with healthy vs higher BMI

Consistent with the idea that deficits in inhibition limit resistance to tempting, tasty, high-calorie foods, and might result in a higher BMI, we test whether people with higher BMIs (BMI >25 kg/m²) present inefficient inhibitory control over food-related responses. To unpack this association, we also examine individual differences in the neural mechanisms of food inhibitory control in healthy vs higher BMI individuals. We test these aspects with a sample of 109 participants (49 with higher BMI and 60 with healthy BMI) and the food stop-signal task, which was used to examine individuals' inhibitory control. Results demonstrated that people with higher BMI had significantly poorer food inhibitory control than healthy BMI individuals. fMRI results showed that, in both Go (Go_food vs Go_nature) and Stop conditions (Stop_food vs Stop_nature), compared to healthy BMI individuals, individuals with higher BMI had lower activation in the superior frontal gyrus, precuneus, precentral gyrus, and supramarginal gyrus in the food stimulus condition. Moreover, ROI analysis results showed that under the Stop_food condition, the activation in the inferior frontal gyrus in the higher BMI group was significantly negatively correlated with inhibitory control abilities. These results suggest that people with a higher BMI have limited ability to inhibit food impulsions, and that the prefrontal regions and parietal cortex may contribute to the progression of inhibitory control limitations in relation to food.

Modified cue exposure for adolescents with binge eating behaviour: study protocol of a randomised pilot trial called EXI(ea)T

INTRODUCTION

Binge eating (BE) behaviour is highly prevalent in adolescents, and can result in serious metabolic derangements and overweight in the long term. Weakened functioning of the behavioural inhibition system is one potential pathway leading to BE. Food cue exposure focusing on expectancy violation (CE_EV) is a short intervention for BE that has proven effective in adults but has never been tested in adolescents. Thus, the current randomised pilot trial evaluates the feasibility of CE_EV for adolescents and its efficacy in reducing eating in the absence of hunger (EAH) of binge food items.

METHODS AND ANALYSIS

The trial will include N=76 female adolescents aged between 13 and 20 years with a diagnosis of bulimia nervosa, binge eating disorder (BED) or their subthreshold forms based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). Participants will be randomly assigned to two sessions of CE_EV or behavioural analysis (BA), a classical cognitive-behavioural therapy-based intervention. The primary endpoint is the change in EAH measured according to ad libitum consumption of personally preferred binge food in a bogus taste test at post-test based on the intention-to-treat population. Key secondary endpoints are changes in EAH of standardised binge food at post-test, in EAH at 3-month follow-up (FU) and in food craving after induction of food cue reactivity at post-test and FU. To identify further valid outcome parameters, we will assess effects of CE_EV compared with BA on global ED psychopathology, BE frequency within the last 28 days, body weight, response inhibition and emotion regulation abilities. Treatment groups will be compared using analysis of covariance with intervention as fixed factor and body mass index at baseline as covariate.

ETHICS AND DISSEMINATION

This clinical trial has been approved by the Ethics Review Committee of the Medical Association of Rhineland-Palatinate and the Medical Faculty of the Ruhr-University Bochum. The collected data will be disseminated locally and internationally through publications in relevant peer-reviewed journals and will be presented at scientific and clinical conferences. Participants data will only be published in an anonymised form.

TRIAL REGISTRATION NUMBER

DRKS00024009.

Loss of control as a transdiagnostic feature in obesity-related eating behaviours: A systematic review

OBJECTIVE

Emerging evidence suggests that loss of control (LOC) may present as a common feature across disordered eating behaviours. However, there has been limited research on the transdiagnostic nature of LOC in this area. The primary aim of this study was to systematically review disordered eating behaviours and measures of LOC in clinical and non-clinical populations.

METHOD

Electronic searches of the relevant databases were conducted. Selected articles were screened for eligibility and assessed for methodological quality.

RESULTS

Thirty-four studies met inclusion criteria. Findings demonstrated that LOC was associated with disordered eating behaviours across bariatric populations, eating disorder populations, and community populations. Specifically, LOC was associated with binge eating (subjective and objective episodes), grazing, night eating, and emotional or stress eating. Findings also revealed that LOC was inconsistently operationalised across studies, with varied approaches to measuring the construct.

CONCLUSION

Overall, the findings from this review provide support for LOC as a transdiagnostic feature of disordered eating behaviours. Future studies should utilise robust multi-method assessments to measure the severity of LOC, which may provide greater insight into how LOC manifests across different eating disorder presentations.

A p-curve analysis of the emotional Stroop effect among women with eating disorders

OBJECTIVE

A recent meta-review of attentional bias research in eating disorders suggests that meta-analyses and systematic reviews include many low-quality and underpowered studies (Stott et al., 2021). As such, we examined whether published research examining the link between attentional bias, using the emotional Stroop task, and eating disorders among women with eating disorders has evidential value (ruling out selective reporting of a statistically significant effect) using a p-curve analysis. A p-curve analysis plots statisticall significant p-values onto a curve from .01 to .05 to examine its distribution. We hypothesized that the p-curve would be flat, indicating no true effect.

METHOD

The hypothesis, database search strategy, and data analytic approach were pre-registered. The inclusion criteria were reports that compared control and eating disorder groups, reported inferential statistics, and that used body shape/weight or general threat target words.

RESULTS

Fifty published reports were included in the p-curve analyses. Unexpectedly, the half and full p-curves were significantly right-skewed, indicating evidential value. However, the results were not robust to the exclusion of the seven lowest p-values and on average, reports were underpowered. There were also 18 reports with null results (they had a p-value greater than .05), which precluded their inclusion in the p-curve analyses.

DISCUSSION

The findings suggest that most of the evidence from research examining attentional biases using the emotional Stroop task among women with an eating disorder or with elevated eating disorder symptoms is underpowered and so should be interpreted with considerable caution.

PUBLIC SIGNIFICANCE

Concerns have been raised about the low quality of research examining attentional biases among women with eating disorders using the emotional Stroop task. In the current research, we observed that the evidential value of primary research reporting differences between women with and without eating disorders was equivocal and had low statistical power. These results can guide researchers towards conducting more rigorous research on attentional biases among people with eating disorders.

Association between impulsivity and orthorexia nervosa: any moderating role of maladaptive personality traits?

OBJECTIVES

To explore the possible moderating relation between impulsive behavior and maladaptive personality traits in regards to orthorexia nervosa (ON).

METHODS

This cross-sectional study was conducted between July and December 2019 and recruited 519 Lebanese adults from seven community pharmacies randomly selected from a list provided by the Lebanese Order of Pharmacists. The Teruel Orthorexia Scale (TOS) was employed to assess orthorexic eating tendencies, the I-8 measured impulsivity and the Personality Inventory for DSM-5 (PID) evaluated maladaptive personality traits.

RESULTS

Our results showed that, for I-8 subscales, only higher perseverance (B = 0.31) was significantly associated with higher ON. In regard to PID-5 subscales, only higher negative affect (B = - 0.34) was significantly associated with lower ON. Furthermore, significant interactions were found between personality traits and impulsivity to predict TOS-ON.

CONCLUSION

The current results show that female gender, maladaptive personality traits and impulsivity present contributing factors regarding orthorexic eating. Certain impulsivity dimensions were confirmed to interact with personality traits in the prediction of orthorexic eating thereby highlighting possible risk factors and psychopathological mechanisms.

LEVEL OF EVIDENCE

Level V, cross-sectional descriptive study.

Cognitive function in binge eating disorder and food addiction: A systematic review and three-level meta-analysis

BACKGROUND

An extensive body of recent research has focused on the contribution of cognitive functioning to eating behaviors. In binge eating disorder (BED) and food addiction (FA), the extent of cognitive impairment is still unclear. This study aimed to characterize, among those with BED and FA, neurocognitive functions using performances based on neuropsychological tasks in the context of neutral stimuli in adults.

METHOD

MEDLINE, Embase, PsycINFO, Cochrane Database of Systematic Reviews, CINAHL and gray literature (ProQuest and OpenGrey) were used to identify studies that reported neurocognitive assessments in BED or FA up to December 2019. A three-level meta-analysis was conducted.

RESULTS

A significant overall effect was found for global cognitive impairments, suggesting that individuals with BED or FA have poorer performances when completing cognitive tasks. Analyses for specific cognitive domains revealed that individuals with BED showed poorer performances at tasks assessing cognitive flexibility, inhibitory control, attention and planning. Analyses regarding FA were inconclusive due to a lack of studies. Thus, the results were described qualitatively.

CONCLUSION

Our meta-analysis highlighted the cognitive weaknesses that seem to come with BED and the necessity to integrate them in the assessment and treatment of this condition. It also stressed the lack of quality studies surrounding the cognitive features of FA.

A cross-sectional examination of executive function and its associations with grazing in persons with obesity with and without eating disorder features compared to a healthy control group

PURPOSE

The current study aimed to investigate associations between grazing and different facets of executive functioning in persons with obesity with and without significant eating disorder psychopathology, compared to a healthy-weight control group.

METHODS

Eighty-nine participants (of which 20 had obesity and marked eating disorder symptomatology, 25 had obesity but without marked eating disorder symptoms, and 44 were healthy-weight age- and sex-matched participants; N = 89; 66.3% female, age = 28.59 (8.62); 18.18-58.34 years) completed a battery of neuropsychological tests and demographic and eating disorder-related questionnaires. Poisson, Negative Binomial, and Ordinary Least Squares regressions were performed to examine group differences and the associations of grazing with executive functioning within the three groups.

RESULTS

Significantly lower inhibitory control and phonemic fluency were observed for the obesity group without ED features compared to healthy-weight controls. Increasing grazing severity was associated with improved performance in inhibitory control in both groups with obesity, and with phonemic fluency in the obesity group with marked eating disorder features.

CONCLUSION

Although there is mounting evidence that specific cognitive domains, especially inhibition, are affected in obesity, evidence of further detrimental effects of eating disorder psychopathology remains mixed; additionally, for persons with obesity, there may be a weak but positive link between executive functioning and grazing behaviour.

LEVEL OF EVIDENCE

III, comparative cross-sectional observational study with a concurrent control group.

A Pilot Event-Related Potentials Study on Mechanisms Underlying a tDCS-Enhanced Food-Specific Response Inhibition Task for Patients With Binge Eating Disorder

Behavioural studies demonstrate alterations in cognitive functioning, particularly impaired response inhibition and increased attentional bias towards food in binge eating disorder (BED). This pilot study aimed to investigate the neurophysiological processing of a food-specific inhibition training combined with anodal transcranial direct current stimulation (tDCS) of the right dorsolateral prefrontal cortex (DLPFC) in 16 patients with BED (mean age = 38.6, mean BMI = 33.7 kg/m²). Patients performed a food-specific antisaccade task at baseline (T0) and in a cross-over design with verum vs. sham stimulation at T1 and T2. We investigated (i) event-related potentials (ERPs; N2, ERN and P3 amplitudes) while executing the task at baseline, (ii) whether baseline ERPs would predict task performance at T1 and T2 and (iii) associations between ERPs, eating disorder pathology and impulsivity at baseline. The mean amplitude of N2 was less pronounced in erroneous saccades (ES) than correct saccades (CS), whereas ERN and P3 mean amplitudes were more pronounced in ES. Moreover, the P3 mean amplitude of ES predicted the percentage of ES at both follow up-measurements irrespective of the applied stimulation (sham vs. verum). N2 in trials with correct saccades were negatively correlated with nonplanning trait impulsivity, while P3 in erroneous antisaccade trials was negatively correlated with food-related impulsivity. Overall, the findings of reduced ERN, enhanced P3 and N2 amplitude might be interpreted as difficulties in response inhibition towards food in individuals with BED. In particular, P3 predicts task outcome at follow-up and might represent a potential marker for inhibitory control processes.

Food Addiction and Its Relationship to Weight- and Addiction-Related Psychological Parameters in Individuals With Overweight and Obesity

Background and Aims: It is assumed that a relevant subgroup of individuals experiences an addiction-like eating behaviour (Food Addiction), characterized by an impaired control over eating behaviour, emotional eating and food craving. Individuals experiencing Food Addiction partially share common symptomatology with Binge-Eating-Disorder and Bulimia Nervosa. The aim of this study was to investigate the prevalence of Food Addiction, general psychopathology, and associations with weight- and addiction-related constructs in individuals with overweight and obesity, who did not suffer from Binge-Eating-Disorder or Bulimia Nervosa.

Methods:N=213 (67.1% female; M_BMI=33.35kg/m², SD_BMI=3.79kg/m²) participants who were included in a weight loss program (I-GENDO project) reported BMI and completed questionnaires before the start of the treatment. Food Addiction severity, depressive symptoms, alcohol use disorder, internet use disorder, psychological distress, impulsivity personality trait, impulsive and emotional eating behaviour, food related inhibitory control, weight bias internalization, and self-efficacy were assessed.

Results: The prevalence of Food Addiction was 15% with higher, although not statistically significant, prevalence in female (18.2%) compared to male (8.6%) participants. Food Addiction was associated with higher BMI at baseline assessment, low self-esteem, impulsive and emotional eating behaviour, weight bias internalization, and deficits in food-related inhibitory control. In addition, correlations were found between Food Addiction and severity of depressive symptoms, internet use disorder, and psychological distress.

Conclusion: A relevant subgroup of participants experiences Food Addiction even when controlling for Binge-Eating-Disorder and Bulimia Nervosa. Future studies are warranted that investigate whether Food Addiction affects treatment success.

A meta-analysis of the relationship between eating restraint, impaired cognitive control and cognitive bias to food in non-clinical samples

AIM

Food restriction is argued to be a precursor for unhealthy preoccupation with food, possibly leading to the development of an eating disorder. We updated previous meta-analyses that examined the relationship between eating restraint and deficits in either general or food-related attentional and inhibitory control. We hypothesized that inconsistencies in the literature around eating restraint, impaired cognitive control, impulsivity and cognitive biases for food could be attributed to the scale used to measure eating restraint.

METHOD

A (preregistered) subgroup meta-analysis examined whether patterns of impaired cognitive control and cognitive bias for food in predominantly healthy (non-clinical) samples differed as a function of the scale used to measure eating restraint. A series of exploratory meta-analyses were carried out for specific attentional bias tasks. In total 57 datasets were included.

RESULTS

The subgroup analysis did not provide evidence that the relationship between eating restraint and impaired or biased cognitions differed significantly as a function of restraint scale. Heterogeneity across studies was high. When examining specific attentional bias tasks there was no evidence that increased eating restraint was associated with increased attentional bias or distraction by food cues, regardless of which scale was used to measure eating restraint.

CONCLUSIONS

There is little experimental evidence for the common narrative that increased eating restraint is related to impaired cognitive control generally or increased cognitive bias for food, in non-clinical samples.

Impulsivity and compulsivity in binge eating disorder: A systematic review of behavioral studies

BACKGROUND

Binge eating disorder (BED) often includes impulsive and compulsive behaviors related to eating behavior and food. Impulsivity and compulsivity generally may contribute to the etiology and maintenance of multiple psychiatric disorders including BED. This review aimed to identify and synthesize available behavioral studies of impulsivity and compulsivity among individuals with BED.

METHOD

A systematic search was performed focusing on BED and specific facets of impulsivity (rapid response and choice) and compulsivity (set-shifting, cognitive flexibility, and/or habit learning). All case-control studies comparing adults with either full-threshold or subthreshold BED to individuals with normal weight, overweight/obesity, or other eating disorders (e.g., bulimia nervosa) were included.

RESULTS

Thirty-two studies representing 29 unique samples met inclusion criteria. Increased choice impulsivity was observed among individuals with BED relative to individuals with normal weight. There were mixed findings and/or a lack of available evidence regarding rapid response impulsivity and compulsivity. The presence of between-group differences was not dependent on sample characteristics (e.g., full or sub threshold BED diagnosis, or treatment-seeking status). Heterogeneity relating to covariates, task methodologies, and power limited conclusions.

CONCLUSIONS

Literature supports a postive association between choice impulsivity and BED. More research is needed to determine if individuals with BED demonstrate elevated levels of either rapid response impulsivity or types of compulsivity. Careful selection of covariates and consideration of task methodologies and power would aid future research.

Loss of control over eating: A systematic review of task based research into impulsive and compulsive processes in binge eating

Recurring episodes of excessive food intake in binge eating disorder can be understood through the lens of behavioral control systems: patients repeat maladaptive behaviors against their explicit intent. Self-report measures show enhanced impulsivity and compulsivity in binge eating (BE) but are agnostic as to the processes that might lead to impulsive and compulsive behavior in the moment. Task-based neurocognitive investigations can tap into those processes. In this systematic review, we synthesize neurocognitive research on behavioral impulsivity and compulsivity in BE in humans and animals, published between 2010-2020. Findings on impulsivity are heterogeneous. Findings on compulsivity are sparse but comparatively consistent, indicating an imbalance of goal-directed and habitual control as well as deficits in reversal learning. We urge researchers to address heterogeneity related to mood states and the temporal dynamics of symptoms, to systematically differentiate contributions of body weight and BE, and to ascertain the validity and reliability of tasks. Moreover, we propose to further scrutinize the compulsivity findings to unravel the computational mechanisms of a potential reinforcement learning deficit.

Diet, Physical Activity, and Disinhibition in Middle-Aged and Older Adults: A UK Biobank Study

Disinhibition is a prominent feature of multiple psychiatric disorders, and has been associated with poor long-term somatic outcomes. Modifiable lifestyle factors including diet and moderate-to-vigorous physical activity (MVPA) may be associated with disinhibition, but their contributions have not previously been quantified among middle-aged/older adults. Here, among N = 157,354 UK Biobank participants aged 40-69, we extracted a single disinhibition principal component and four dietary components (prudent diet, elimination of wheat/dairy/eggs, meat consumption, full-cream dairy consumption). In addition, latent profile analysis assigned participants to one of five empirical dietary groups: prudent-moderate, unhealthy, restricted, meat-avoiding, low-fat dairy. Disinhibition was regressed on the four dietary components, the dietary grouping variable, and self-reported MVPA. In men and women, disinhibition was negatively associated with prudent diet, and positively associated with wheat/dairy/eggs elimination. In men, disinhibition was also associated with consumption of meat and full-cream dairy products. Comparing groups, disinhibition was lower in the prudent-moderate diet (reference) group compared to all other groups. Absolute βs ranged from 0.02-0.13, indicating very weak effects. Disinhibition was not associated with MVPA. In conclusion, disinhibition is associated with multiple features of diet among middle-aged/older adults. Our findings foster specific hypotheses (e.g., early malnutrition, elevated immune-response) to be tested in alternative study designs.

Clinical binge eating, but not uncontrolled eating, is associated with differences in executive functions: Evidence from meta-analytic findings

•

To study the relationship between executive functions and binge eating behaviors.

•

Executive functions do not differ along non-clinical binge eating patterns.

•

Binge eating disorder might be related with small deficits in executive function.

•

Mood disorders linked with severe binge eating might influence cognitive deficits.

Introduction

Binge eating disorder (BED) is a common psychiatric diagnosis characterized by the presence of episodes of loss of control over food consumption. Understanding the neurocognitive factors associated with binge eating pathology might help to design clinical strategies aimed at preventing or treating BED. However, results in the field are notably heterogeneous. In the current study, we aimed to establish whether binge eating behaviors (both at a clinical and at a non-clinical level) are associated with executive functions.

Methods

We performed a pre-registered meta-analysis to examine the link between executive functions, BED, and uncontrolled eating, a psychobiological construct closely associated with binge eating behaviors. Articles were searched on PubMed and the main exclusion criteria were lack of information about participants’ age or sex distribution or adiposity measurements, studies performed in older populations (age > 65 years old) or studies including participants with purging symptoms.

Results

Relative to healthy controls, patients with BED showed lower performance in executive functions, with a small effect size. At the same time, uncontrolled eating patterns were not associated with differences in executive functions. Neither age nor body mass index (BMI) influenced these results.

Conclusions

Our findings suggest that there is no association between performance in executive functions and variations along the non-clinical spectrum of binge eating behaviors. Small deficits in executive functions, however, seem to appear in individuals showing severe binge eating symptoms, that is, individuals meeting diagnostic criteria for BED. We speculate that the close links between BED and emotional distress could partly explain these results.

Relating goal-directed behaviour to grazing in persons with obesity with and without eating disorder features

BACKGROUND

Both obesity and eating disorders (ED) have been associated with reductions in purposeful, flexible goal-directed behaviour, and with an overreliance on more rigid habitual behaviour. It is currently unknown whether grazing, an eating style which is common in both conditions, is related to goal-directed behaviour. The current study therefore aimed to relate grazing to goal-directed behaviour in a group of participants with obesity with and without ED features, compared to a healthy-weight control group.

METHODS

Participants (N = 87; 67.8% women, mean age 28.57 years), of whom 19 had obesity and significant eating disorder features, 25 had obesity but without marked eating disorder features, and 43 were age- and sex-matched healthy-weight controls, completed two instrumental learning tasks assessing action-outcome contingency sensitivity and devaluation sensitivity, as well as demographic and eating disorder-related questionnaires. Gamma and Ordinary Least Squares regressions were performed to examine the effect of group and grazing on goal-directed behaviour.

RESULTS

Lower action-outcome contingency sensitivity was found in the group with obesity and with eating disorder features than in the group with obesity but without eating disorder features or in healthy controls. No group differences in devaluation sensitivity were found. A small but significant relationship was found between grazing severity and contingency sensitivity in the group with obesity and eating disorder features, such that increasing grazing severity was associated with less diminished contingency sensitivity.

CONCLUSIONS

There is some indication that in persons with obesity and eating disorder features instrumental behaviour is less flexible and adaptive; furthermore, within this group grazing may represent a goal-directed behaviour, despite unhelpful long-term implications of grazing.

Linking Grazing to Inhibition and Goal-Directed Behaviour in Obesity With and Without Eating Disorder Features

Recent models of obesity and eating behaviour have implicated both automatic responding to food-related cues and executive functioning in driving dietary choice. This study aimed to relate grazing severity to high weight with and without significant eating disorder features via the effects of inhibition and degree of goal-directed behaviour, in persons with obesity with and without significant eating disorder features compared to healthy controls. Forty-four participants with obesity (43.1% endorsing marked eating disorder features), and 43 healthy-weight age- and sex-matched participants (N = 87; 67.8% female, age = 28.57 (8.70; 18.18–58.34) years, BMI = 29.18 (7.80; 18.65–51.95) kg/m2) completed demographic and eating disorder-related questionnaires, a neuropsychological task of inhibition and an instrumental decision-making task. Bootstrapped serial mediation analyses were performed to examine the effect of group on grazing via goal-directed behaviour and inhibition. While significant differences existed between the groups in terms of inhibition, goal-directed behaviour and grazing severity, the effect of group on grazing severity was not found to be mediated by the degree of behavioural goal-directedness and inhibition. Therefore, :in persons with obesity with or without eating disorder symptoms, putative relationships between a reduced inhibitory profile and/or behaviour that is less flexible and goal-directed and eating behaviours such as grazing, remain unclear.

"Food" and "non-food" self-regulation in childhood: a review and reciprocal analysis

BACKGROUND

In developmental science, there is an extensive literature on non-food related self-regulation in childhood, where several domains relating to emotions, actions and cognitions have been identified. There is now growing attention to food related self-regulation in childhood, especially difficulties with ASR, and the consequences for weight gain and adiposity. The aim of this narrative review was to conduct a reciprocal analysis of self-regulation in the food and non-food domains in childhood (referred to as appetite self-regulation (ASR) and general self-regulation (GSR) respectively). The focus was on commonalities and differences in key concepts and underpinning processes.

METHODS

Databases and major journals were searched using terms such as self-regulation, appetite self-regulation, or self-regulation of energy intake, together with associated constructs (e.g., Executive Function, Effortful Control, delay-of-gratification). This was followed by backward and forward snowballing.

RESULTS AND DISCUSSION

The scholarship on GSR in childhood has had a focus on the role of the cognitively-oriented Executive Function (EF), the temperamentally-based Effortful Control (EC) and the recursive interplay between bottom-up (reactive, emotion driven, approach or avoidance) and top-down (cognitive, conscious decision-making) processes. "Hot" and "cool/cold" EF and self-regulation situations have been distinguished. There were some parallels between GSR and ASR in these areas, but uncertainty about the contribution of EF and EC to ASR in young children. Possible differences between the contribution to ASR-related outcomes of delay-of-gratification in food and non-food tasks were apparent. Unique elements of ASR were identified; associated with psychological, biological and neurological responses to food and bottom-up processes. A diverse number of situations or elements connected to ASR exist: for example, energy balance homeostasis, caloric compensation, hunger regulation, satiation, satiety, energy density of food, eating in the absence of hunger, emotional eating, etc. CONCLUSIONS: Self-regulation in food and non-food domains are amenable to a reciprocal analysis. We argue that self-regulation of appetite should be added as a domain under the umbrella of self-regulation in childhood along with the other non-food related domains. This could lead to a broader understanding of self-regulation in childhood, and generate novel lines of enquiry.

The Clinical Obesity Maintenance Model: A Theoretical Framework for Bariatric Psychology

Ranked highly in its association with serious medical comorbidities, obesity, a rapidly growing epidemic worldwide, poses a significant socio-economic burden. While bariatric procedures offer the most efficacious treatment for weight loss, a subset of patients risk weight recidivism. Due to the heterogeneity of obesity, it is likely that there are phenotypes or sub-groups of patients that require evidence-based psychological support to produce more sustainable outcomes. So far, however, characteristics of patients have not led to a personalized treatment algorithm for bariatric surgery. Maintenance of weight loss following bariatric surgery requires long-term modification of eating behaviors and physical activity. A recent Clinical Obesity Maintenance Model (COMM) proposed a conceptual framework of salient constructs, including the role of habit, behavioral clusters, emotion dysregulation, mood, health literacy, and executive function as interconnected drivers of obesity maintaining behaviors relevant to the field of bariatric psychology. The primary aim of this concise review is to bring together emerging findings from experimental and epidemiological studies relating to the COMM constructs that may inform the assessment and follow up of bariatric surgery. We also aim to explain the phenotypes that need to be understood and screened prior to bariatric surgery to enable better pre-surgery intervention and optimum post-surgery response.

Scrutinizing Domains of Executive Function in Binge Eating Disorder: A Systematic Review and Meta-Analysis

BACKGROUND

Cognitive deficits are implicated in theoretical explanatory models for binge eating disorder (BED). Furthermore, evidence suggest that alterations in executive function may underlie symptoms in BED. The current systematic review and meta-analysis provides an update on executive functioning in individuals with BED.

METHODS

Literature searches (up to November 2019) were conducted in electronic databases combining binge eating or BED with executive functions. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement guidelines was used. Studies of any design comparing adults with BED with those without BED in executive function domains were selected. Methodological quality of studies was based on the Newcastle-Ottawa scale.

RESULTS

Of 1,983 citations identified, 28 case-control studies met inclusion criteria for this review. Six meta-analyses that examined four domains (decision-making, cognitive flexibility, inhibitory control, and working memory) were conducted. The only meta-analysis to show a significant difference in executive functioning between BED and obese controls was working memory (SMD = 0.32, 95% IC: -0.60, -0.03; p = 0.028), with an effect size of small magnitude. Qualitative inspection of the literature indicated mixed findings for control inhibition, decision making and cognitive flexibility in individuals with BED compared to controls (obese or normal weight). In addition, people with BED showed poorer problem solving performance, but similar planning abilities to obese controls.

CONCLUSIONS

Individuals with BED were found to show worse performance on working memory tasks compared to obese individuals without the disorder. The findings did not provide definitive evidence of alterations in other aspects of executive functioning. Interest in executive functioning in people with BED is increasing but is limited by insufficient data from small studies with varied methodology. Future studies should focus on using similar tests and outcome measures, in order to enable more pertinent comparisons across studies.

Verbesserung der Impuls- und Emotionsregulation bei Binge-Eating-Störungen

Zusammenfassung. Impulsivität beeinflusst die Verarbeitung von störungsspezifischen Reizen und die Handlungskompetenz hinsichtlich der Nahrungsaufnahme. Neuere Studien adressieren daher unterschiedliche Facetten impulsiven Erlebens und Verhaltens, um eine Reduktion von Essanfällen und des Körpergewichts bei der Binge-Eating-Störung (BES) zu erzielen. ImpulsE ist ein Therapieprogramm zur Verbesserung der Impuls- und Emotionsregulationsfertigkeiten, welches mit einem computergestützten nahrungsbezogenen Inhibitionstraining kombiniert und mit einer Standardbehandlung (TAU) verglichen wurde. N = 31 Personen mit BES nahmen teil (n = 22 ImpulsE, n = 9 TAU). Die Ergebnisse zeigten Verbesserungen in der nahrungsbezogenen Verhaltensinhibition und der allgemeinen Essstörungspathologie in beiden Gruppen, während sich die Anzahl von Essanfällen nur bei ImpulsE signifikant senkte. Die Ergebnisse stellen erste Hinweise auf die Wirksamkeit eines solchen Trainings dar. Eine Adaption an Jugendliche erscheint sinnvoll.