Dietary restraint moderates genetic risk for binge eating

Binge-Eating Precursors in Children and Adolescents: Neurodevelopment, and the Potential Contribution of Ultra-Processed Foods

Binge-eating disorder (BED) is a highly prevalent disorder. Subthreshold BED conditions (sBED) are even more frequent in youth, but their significance regarding BED etiology and long-term prognosis is unclear. A better understanding of brain findings associated with BED and sBED, in the context of critical periods for neurodevelopment, is relevant to answer such questions. The present narrative review starts from the knowledge of the development of emotional self-regulation in youth, and the brain circuits supporting emotion-regulation and eating behaviour. Next, neuroimaging studies with sBED and BED samples will be reviewed, and their brain-circuitry overlap will be examined. Deficits in inhibition control systems are observed to precede, and hyperactivity of reward regions to characterize, sBED, with overlapping findings in BED. The imbalance between reward/inhibition systems, and the implication of interoception/homeostatic processing brain systems should be further examined. Recent knowledge of the potential impact that the high consumption of ultra-processed foods in paediatric samples may have on these sBED/BED-associated brain systems is then discussed. There is a need to identify, early on, those sBED individuals at risk of developing BED at neurodevelopmental stages when there is a great possibility of prevention. However, more neuroimaging studies with sBED/BED pediatric samples are needed.

Group differences in binge eating, impulsivity, and intuitive and mindful eating among intermittent fasters and non-fasters

Intermittent fasting (IF) is an increasingly popular diet involving short-term fasting and/or caloric restriction. While published research highlights physiological effects (e.g., weight, body fat) of IF, hardly any research has examined its associations with psychological factors. This study aimed to investigate the relationship between IF and binge eating, impulsivity, intuitive eating, and mindful eating. An undergraduate sample (N = 298) was recruited through a large southwestern university psychology subject pool. The sample was divided into three groups based on IF status: Current IF (n = 70), Past IF (n = 48), and No IF (n = 182). Current IF was negatively associated with lack of perseverance (e.g., "I generally like to see things through to the end"; p < .01) and intuitive eating (p < .05), varying by subscale, compared to the other groups. Notably, Past-IF, but not Current IF, participants were more likely to binge eat than individuals who reported never fasting (p = .03). These findings add credence to the rapidly developing area of research suggesting IF is associated with increased disordered eating behaviors. Notably, the findings from this study are limited due to the lack of diversity sample, such that generalizations can only be made toward White, middle-to-high income, college students. Future longitudinal studies are needed to test the directionality of these relationships.

Clinical aspects of binge eating disorder: A cross-sectional mixed-methods study of binge eating disorder experts' perspectives

Introduction

Research on binge eating disorder continues to evolve and advance our understanding of recurrent binge eating.

Methods

This mixed-methods, cross-sectional survey aimed to collect information from experts in the field about clinical aspects of adult binge eating disorder pathology. Fourteen experts in binge eating disorder research and clinical care were identified based on receipt of relevant federal funding, PubMed-indexed publications, active practice in the field, leadership in relevant societies, and/or clinical and popular press distinction. Anonymously recorded semi-structured interviews were analyzed by ≥2 investigators using reflexive thematic analysis and quantification.

Results

Identified themes included: (1) obesity (100%); (2) intentional/voluntary or unintentional/involuntary food/eating restriction (100%); (3) negative affect, emotional dysregulation, and negative urgency (100%); (4) diagnostic heterogeneity and validity (71%); (5) paradigm shifts in understanding binge eating disorder (29%); and (6) research gaps/future directives (29%).

Discussion

Overall, experts call for a better understanding of the relationship between binge eating disorder and obesity, including a need for clarification around the extent to which the two health issues are separate vs. related/overlapping. Experts also commonly endorse food/eating restriction and emotion dysregulation as important components of binge eating disorder pathology, which aligns with two common models of binge eating disorder conceptualization (e.g., dietary restraint theory and emotion/affect regulation theory). A few experts spontaneously identified several paradigm shifts in our understanding of who can have an eating disorder (beyond the anorexi-centric "thin, White, affluent, cis-gendered neurotypical female" stereotype), and the various factors that can drive binge eating. Experts also identified several areas where classification issues may warrant future research. Overall, these results highlight the continual advancement of the field to better understand adult binge eating disorder as an autonomous eating disorder diagnosis.

Prevalence and associated factors of binge eating disorder among Bahraini youth and young adults: a cross-sectional study in a self-selected convenience sample

BACKGROUND

Binge eating disorder (BED) is defined as recurrent ingestion of an unusually large amount of food in a discrete period of time. BED has the highest prevalence of all eating disorders. Studies have shown a strong relationship between BED and both physical and psychological factors such as obesity, depression and anxiety. This research aimed to report the prevalence and associated factors of BED among Bahrainis (aged 15-30 years).

METHODS

A total of 959 participants (aged 15-30 years) completed self-administered online questionnaires. BED was measured using the binge eating disorder Screener-7. The Patient Health Questionnaire-9 and General Anxiety Disorder-7 were used to measure depression and anxiety, respectively.

RESULTS

Out of all participants, 21.2% had binge eating symptoms. A higher BMI, a restricted diet, depression and anxiety were associated with more frequent binge eating symptoms. Out of all associated factors, depression had the strongest association with binge eating, (rp = 0.371, p < 0.0001). However, sociodemographic variables including age and other medical conditions were not significantly associated with BED symptoms.

CONCLUSION

In conclusion, the prevalence of BED symptoms was significantly high among the study participants. The results point out the crucial role of awareness of the interaction between obesity, depression and anxiety as potential risk factors for binge eating tendencies. Further research should examine their relationship with BED.

Eating behaviors, eating styles and body mass index during COVID-19 confinement in a college sample: a predictive model

BACKGROUND

COVID-19 confinement affected lifestyles. There is inconclusive evidence about changes in eating patterns, and there are few studies on the impact on body mass index (BMI), the occurrence of dysfunctional behaviors (binge eating, fat intake), and the predictive role of maladaptive eating styles (emotional, external, and restrained eating).

OBJECTIVES

(1) To analyze the differences in binge eating, fat intake, BMI, and maladaptive eating styles before and during COVID-19 confinement, and (2) to analyze whether maladaptive eating styles (before confinement) predicted binge eating, fat intake, and BMI during confinement.

METHODS

The sample consisted of 146 Spanish college students, divided into 104 females (71.2%; age: M = 22.20, SD = 2.97) and 42 males (28.8%; age: M = 24.74; SD = 3.53). All completed several dietary measures and BMI twice: before COVID-19 confinement (T1, November 2019) and during COVID-19 confinement (T2, April 2020).

RESULTS

BMI and maladaptive eating styles did not change in T2 (vs. T1). However, binge eating and fat intake decreased in T2. Emotional eating at T1 positively predicted BMI and binge eating at T2. External eating at T1 positively (and marginally) predicted fat intake at T2. Restrained eating at T1 positively predicted binge eating at T2, and negatively (and marginally) predicted BMI and fat intake at T2. The model explained 80.5% of the variance in BMI, 41.5% of the variance in binge eating, and 25.8% of the variance in fat intake during COVID-19 confinement.

CONCLUSIONS

The COVID-19 confinement had a positive impact on some eating behaviors. Future policies should focus part of their prevention on maladaptive eating styles to curb dysfunctional eating behaviors and BMI problems in times of stress.

The Complicated Relationship between Dieting, Dietary Restraint, Caloric Restriction, and Eating Disorders: Is a Shift in Public Health Messaging Warranted?

The origins of theories specifying dietary restraint as a cause of eating disorders can be traced to the 1970s. This paper will present an overview of the origins of dietary restraint theories and a brief historical review of evidence will be summarized. Recent research will be presented, including the results from the CALERIE Phase 1 study, as well as CALERIE Phase 2, which were NIH-sponsored randomized controlled trials. CALERIE 2 provided a test of the effect of two years of caloric restriction (CR) on the development of eating disorder syndromes and symptoms in comparison to a control group that did not alter eating behavior or body weight. The intervention was effective for inducing a chronic (two-year) reduction in total energy expenditure and increased dietary restraint but did not increase symptoms of eating disorders. The results of this recent investigation and other studies have not provided experimental support for conventional dietary restraint theories of eating disorders. These findings are discussed in terms of potential revisions of dietary restraint theory, as well as the implications for a paradigm shift in public health messaging related to dieting.

The Association of Restrained Eating and Overeating during COVID-19: A Cross-Lagged Model

Widespread overeating has been found during the 2019 coronavirus (COVID-19) pandemic. The present study investigated whether pre-pandemic restrained eating (RE) predicted overeating during the pandemic, and further explored the behavioral (mortality threat, negative affect) mechanisms underlying this association. An eight-month longitudinal survey was conducted with a large sample of 616 undergraduates from Southwest university. From September 2019 to April 2020, three measurements were conducted. RE was tested before the pandemic (T1), and data of mortality threat, negative affect, and overeating were collected at the middle (T2) and end of (T3) the COVID-19 crisis in China. The correlation results showed that baseline RE was positively associated with mortality threat, negative affect, and overeating at T2 and T3. Moreover, negative affect and mortality threat were positively correlated with overeating. Results from longitudinal mediation showed that baseline RE would positively predict T3 overeating through T2 negative affect, but not T2 mortality threat. This study supports and extends the counterregulatory eating hypothesis that RE positively predicts future overeating, especially through negative emotions. These findings further reveal the core psychological mechanism underlying this positive RE-overeating relation in the context of COVID-19, indicating that the individuals with higher RE could not cope with negative affect adequately, contributing to more overeating.

Marital Satisfaction as a Moderator of Molecular Genetic Influences on Mental Health

The quality of one's romantic relationship is associated with mental health. Low levels of relationship quality may be a stressor that triggers a predisposition or diathesis to mental illness. Analyses were conducted to examine whether relationship quality moderated the association between polygenic risk scores (PRSs) for several mental health syndromes on phenotypic measures of those syndromes. Data were drawn from the Midlife in the United States (MIDUS) study of health and well-being. A subsample was genotyped, and PRSs were calculated. The PRS for anxiety was more strongly related to the anxiety phenotype when satisfaction was low than when satisfaction was high, providing evidence of a genetic susceptibility process between marital distress and anxiety. The expression of genetic influences on a phenotype in the presence of certain environmental stressors is complex and may depend on the specific phenotype and the methodology by which genetic influences are estimated.

Emotion regulation difficulties and dietary restraint independently predict binge eating among men

PURPOSE

Research on eating disorder symptoms among men is growing, but there still are few specific models of disordered eating. The aim of the current study is to expand the literature on male eating behavior by investigating how negative affect can lead to binge eating and overeating through possible mediators, i.e., emotion regulation difficulties and dietary restraint, both separately and together in an integrative model.

METHODS

Altogether 104 men (mean age 27.3, SD = 8.02; BMI 24.2, SD = 2.92) participated in the study using ecological momentary assessment to collect data on negative affect, the urge to restrict, and the occurrence of binge eating and overeating episodes. Self-report questionnaires were used to measure emotion regulation difficulties and eating disorder symptoms.

RESULTS

We found that both emotion regulation difficulties and the urge to restrict mediated the effect of negative affect on binge eating in separate models as well as in an integrated model. However, emotion regulation difficulties did not predict the urge to restrict in the joint model. These models did not predict overeating, indicating the pathological nature of binge eating.

CONCLUSIONS

Our data suggest that negative emotions themselves do not lead to binge eating, but manifest through emotion regulation difficulties and dietary restraint. The results indicate that emotion regulation and restraint play a role in precipitating binge eating among men. However, the emotion regulation and restraint pathways seem to operate independently from one another. Our study also supports the differentiation of overeating and binge eating, as these seem to have different etiologies.

LEVEL OF EVIDENCE

Level V, cross-sectional descriptive study.

Food Addiction and Psychosocial Adversity: Biological Embedding, Contextual Factors, and Public Health Implications

The role of stress, trauma, and adversity particularly early in life has been identified as a contributing factor in both drug and food addictions. While links between traumatic stress and substance use disorders are well documented, the pathways to food addiction and obesity are less established. This review focuses on psychosocial and neurobiological factors that may increase risk for addiction-like behaviors and ultimately increase BMI over the lifespan. Early childhood and adolescent adversity can induce long-lasting alterations in the glucocorticoid and dopamine systems that lead to increased addiction vulnerability later in life. Allostatic load, the hypothalamic-pituitary-adrenal axis, and emerging data on epigenetics in the context of biological embedding are highlighted. A conceptual model for food addiction is proposed, which integrates data on the biological embedding of adversity as well as upstream psychological, social, and environmental factors. Dietary restraint as a feature of disordered eating is discussed as an important contextual factor related to food addiction. Discussion of various public health and policy considerations are based on the concept that improved knowledge of biopsychosocial mechanisms contributing to food addiction may decrease stigma associated with obesity and disordered eating behavior.

Separating the Signal from the Noise: How Psychiatric Diagnoses Can Help Discern Food Addiction from Dietary Restraint

Converging evidence from both animal and human studies have implicated hedonic eating as a driver of both binge eating and obesity. The construct of food addiction has been used to capture pathological eating across clinical and non-clinical populations. There is an ongoing debate regarding the value of a food addiction "diagnosis" among those with eating disorders such as anorexia nervosa binge/purge-type, bulimia nervosa, and binge eating disorder. Much of the food addiction research in eating disorder populations has failed to account for dietary restraint, which can increase addiction-like eating behaviors and may even lead to false positives. Some have argued that the concept of food addiction does more harm than good by encouraging restrictive approaches to eating. Others have shown that a better understanding of the food addiction model can reduce stigma associated with obesity. What is lacking in the literature is a description of a more comprehensive approach to the assessment of food addiction. This should include consideration of dietary restraint, and the presence of symptoms of other psychiatric disorders (substance use, posttraumatic stress, depressive, anxiety, attention deficit hyperactivity) to guide treatments including nutrition interventions. The purpose of this review is to help clinicians identify the symptoms of food addiction (true positives, or "the signal") from the more classic eating pathology (true negatives, or "restraint") that can potentially elevate food addiction scores (false positives, or "the noise"). Three clinical vignettes are presented, designed to aid with the assessment process, case conceptualization, and treatment strategies. The review summarizes logical steps that clinicians can take to contextualize elevated food addiction scores, even when the use of validated research instruments is not practical.

Relationship between binge eating and associated eating behaviors with subcortical brain volumes and cortical thickness

BACKGROUND

Binge eating disorder (BED) is the most prevalent eating disorder. We examined the presence of binge eating (BE) and three associated eating behaviors in relation to subcortical regional volumes and cortical thickness from brain scans.

METHODS

We processed structural MRI brain scans for 466 individuals from the Nathan Kline Institute Rockland Sample using Freesurfer. We investigated subcortical volumes and cortical thicknesses among those with and without BE and in relation to the scores on dietary restraint, disinhibition, and hunger from the Three-Factor Eating Questionnaire (TFEQ). We conducted a whole-brain analysis and a region of analysis (ROI) using a priori regions associated with BE and with the three eating factors. We also compared scores on the three TFEQ factors for the BE and non-BE.

RESULTS

The BE group had higher scores for dietary restraint (p = .013), disinhibition (p = 1.22E-07), and hunger (p = 5.88E-07). In the whole-brain analysis, no regions survived correction for multiple comparisons (FDR corrected p<0.01) for either BE group or interaction with TFEQ. However, disinhibition scores correlated positively with left nucleus accumbens (NAc) volume (p < 0.01 FDR corrected). In the ROI analysis, those with BE also had greater left NAc volume (p = 0.008, uncorrected) compared to non-BE.

LIMITATIONS

Limitations include potential self-report bias on the EDE-Q and TFEQ.

CONCLUSIONS

The findings show that BE and disinhibition scores were each associated with greater volumes in the left NAc, a reward area, consistent with a greater drive and pleasure for food.

Evaluation of the relationships between dietary restraint, emotional eating, and intuitive eating moderated by sex

Intuitive eating involves attention to feelings putatively related to hunger and satiety to guide eating choices. This adaptive eating style has been linked to a number of positive physical and psychological outcomes. Interestingly, women tend to report lower levels of intuitive eating compared to men. It has been hypothesized that sociocultural pressures or dieting could be contributing factors to this sex discrepancy. The current study aimed to explore whether sex moderates the relationship between either dietary restraint and intuitive eating, or between emotional eating and intuitive eating. Assessments were administered to a sample of college males and females (N = 478) as part of a larger study of eating behaviors. Moderation analyses indicated that higher dietary restraint was more strongly associated with lower levels of intuitive eating in women than in men. Emotional eating also had a stronger negative association with intuitive eating in women compared to men. Additionally, relationships between dietary restraint/emotional eating and a component of intuitive eating, "eating for physical rather than emotional reasons", was stronger for women compared to men. These findings suggest that dietary restraint and emotional eating may serve as barriers in the implementation of an intuitive eating style, especially for women. Prevention and intervention efforts should target those high in dietary restraint and emotional eating.

Polaprezinc (Zinc-L-Carnosine Complex) as an Add-on Therapy for Binge Eating Disorder and Bulimia Nervosa, and the Possible Involvement of Zinc Deficiency in These Conditions: A Pilot Study

BACKGROUND

Zinc plays an important role in appetite regulation. L-Carnosine, an endogenous dipeptide, may also regulate eating behavior via its histaminergic and antiglutamatergic properties. Polaprezinc (zinc-L-carnosine complex) is a medication for gastric ulcers. A small case series reported successful treatment of binge eating with add-on polaprezinc.

METHODS

This was an open trial of add-on polaprezinc in patients with binge eating disorder (BED; n = 22) or bulimia nervosa (BN; n = 7) receiving antidepressants. A 4-week baseline period was followed by a 16-week polaprezinc treatment at 150 mg/d (containing 34 mg zinc and 116 mg L-carnosine) in addition to ongoing psychotropic medications. We also assessed their zinc status via a laboratory index and zinc deficiency-related symptoms.

RESULTS

At the study end, both conditions showed a significant reduction in the 4-week frequency of combined objective and subjective binge eating episodes, the 4-week frequency of days when at least 1 such episode occurred (only in BED), several aspects of eating disorder psychopathology (rated by the Eating Disorder Examination-Questionnaire), and comorbid depressive symptoms (rated by the 16-item Quick Inventory of Depressive Symptomatology [Self-Report]). Serum copper/zinc ratio decreased from 1.4 to 1.1 on average in both conditions. All patients had multiple zinc deficiency-related symptoms at baseline that substantially improved after polaprezinc treatment. Overall, the effectiveness of polaprezinc was greater in BED patients than in BN patients, with minor adverse effects.

CONCLUSIONS

These findings offer preliminary evidence for the effectiveness of polaprezinc in treating BED and BN and suggest the involvement of zinc deficiency in these conditions.

The psychological characteristics of people consuming vegetarian, vegan, paleo, gluten free and weight loss dietary patterns

OBJECTIVE

Previous research has identified several psychological factors associated with dietary restriction but has focused almost exclusively on the subcategory of people following a weight loss diet. Little is known about the psychological factors associated with other kinds of restrictive dietary patterns. Furthermore, it remains unclear whether the identified psychological characteristics of dieters (e.g. elevated disordered eating behaviours, poor well-being) are a cause of dieting, follow from calorie restriction or are the result of cognitive restraint.

METHODS

This study conducted the first direct comparison of people (N = 393) following five different restrictive dietary patterns (vegetarian, vegan, gluten free, paleo and weight loss) as well as a comparison group who were not following a specific dietary pattern.

RESULTS

The weight loss group had more negative psychological characteristics than all other groups, reporting the highest levels of eating disorder symptoms (M = 1.50), food cravings (M = 69.39), emotional eating (M = 2.97) and negative affect (M = 19.72). By contrast, several of the other restrictive dietary groups showed a number of psychological strengths, relative to the comparison group. This was particularly apparent among the paleo group, who reported the lowest levels of eating disorder symptoms (M = 0.74), food cravings (M = 47.63), emotional eating (M = 2.30) and negative affect (M = 14.81). By contrast, people following vegetarian and gluten free diets were largely the same as the non-restricted comparison group in their psychological characteristics.

CONCLUSIONS

People adhering to different dietary patterns showed stark differences in their psychological characteristics. Indeed, some restrictive dietary patterns (paleo and vegan) were associated with more positive psychological characteristics than seen in an unrestricted comparison group. This suggests that the psychological risk factors seen in weight loss dieters are not attributable to a restrictive dietary regimen per se.

Eating disorder-specific risk factors moderate the relationship between negative urgency and binge eating: A behavioral genetic investigation

Theoretical models of binge eating and eating disorders include both transdiagnostic and eating disorder-specific risk factors. Negative urgency (i.e., the tendency to act impulsively when distressed) is a critical transdiagnostic risk factor for binge eating, but limited research has examined interactions between negative urgency and disorder-specific variables. Investigating these interactions can help identify the circumstances under which negative urgency is most strongly associated with binge eating. We examined whether prominent risk factors (i.e., appearance pressures, thin-ideal internalization, body dissatisfaction, dietary restraint) specified in well-established etiologic models of eating disorders moderate negative urgency-binge eating associations. Further, we investigated whether phenotypic moderation effects were due to genetic and/or environmental associations between negative urgency and binge eating. Participants were 988 female twins aged 11-25 years from the Michigan State University Twin Registry. Appearance pressures, thin-ideal internalization, and body dissatisfaction, but not dietary restraint, significantly moderated negative urgency-binge eating associations, with high levels of these risk factors and high negative urgency associated with the greatest binge eating. Twin moderation models revealed that genetic, but not environmental, sharing between negative urgency and binge eating was enhanced at higher levels of these eating disorder-specific variables. Future longitudinal research should investigate whether eating disorder risk factors shape genetic influences on negative urgency into manifesting as binge eating. (PsycINFO Database Record

Weight-related peer-teasing moderates genetic and environmental risk and disordered eating: twin study

BackgroundWeight-related peer-teasing is considered a potent prospective risk factor for development of disordered eating and clinical eating disorders. Currently, the interplay between genetic and environmental influences has yet to be elucidated.AimsTo determine whether peer-teasing moderates latent genetic and/or environmental risk for disordered eating among female adolescent twins.MethodFull quantitative gene-environment interplay modelling of longitudinal trajectory of disordered eating in 685 female twins from the Australian Twin Registry.ResultsA model permitting moderation of disordered eating by peer-teasing involving genetic and non-shared environment effects fit these data best. As levels of peer-teasing increased, both genetic and environmental influences on disordered eating strengthened; however, genetic sources increased proportionally more than environmental sources.ConclusionsWeight-related peer-teasing represents a particularly powerful trigger for disordered eating. Nevertheless, it is amenable to intervention/prevention activities spanning individual to universal levels of endeavour.

Effects of a cognitive-behavioral exposure-based body image therapy for overweight females with binge eating disorder: a pilot study

BACKGROUND

Although not part of the diagnostic criteria of the DSM-5, body image disturbance seems to be a relevant feature of Binge Eating Disorder (BED) as well as of other eating disorders such as Anorexia Nervosa (AN) or Bulimia Nervosa (BN). Hence, the aim of the present pilot study was to assess the changeability of body image disturbance in a sample of overweight females with BED by a cognitive-behavioral treatment, directly addressing body image disturbance.

METHOD

Overweight females (N = 34) with BED were randomized to a manualized body image therapy or a waiting-list control group. The final sample consisted of n = 15 participants in the intervention group and n = 19 in the control group due to two drop-outs in the control condition. Before and after the intervention or the waiting period, respectively, participants filled out a questionnaire battery assessing several body image and eating disorder related features. To quantify the perceptual component of body image disturbance, a digital photo distortion technique based on a picture of each participant taken in a standardized suit was applied.

RESULTS

In a two-way ANOVA, significant Time × Group interactions were found for eating and shape concerns, drive for thinness, body dissatisfaction, depressiveness and low self-esteem. Follow-up t-tests indicated a significant symptom reduction of a generally high magnitude in the intervention group. No significant changes concerning body checking and the estimations of one's own "real", "felt" and "ideal" body dimensions were found.

CONCLUSION

The strong symptom reduction in the cognitive-affective component of body image disturbance indicates that an exposure-based cognitive-behavioral body image intervention is a promising treatment module for overweight females with BED, but future research with a larger sample size is needed to quantify possible changes in all components of body image.

Patterned feeding induces neuroendocrine, behavioral and genetic changes that promote palatable food intake

BACKGROUND

Selection of a healthy diet is the cornerstone for treating obesity and metabolic disease. Unfortunately, the majority of diets fail leading to weight regain and in some cases, pathological feeding behavior. We hypothesize that alternating bouts of caloric overconsumption and caloric restriction, behavioral manifestations of dieting induce neuroendocrine, behavioral and genetic changes that promote future bouts of palatable food intake.

METHODS

To test this hypothesis, we subjected male Long-Evans rats to a high-fat diet (HFD) feeding paradigm that induced a pattern of caloric overconsumption and caloric restriction. Under these conditions we measured operant responding for sucrose, pre-meal ghrelin secretion, the effects of peripheral ghrelin blockade on patterned feeding, HFD intake in an aversive environment and mRNA expression of the ghrelin receptor, orexin, orexin-1 and 2 receptors, and FTO in the medial prefrontal cortex, lateral hypothalamus and ventral tegmental area.

RESULTS

Rats subjected to this feeding regimen displayed increased ghrelin levels prior to HFD exposure and blockade of this response attenuated patterned feeding behavior. In addition, patterned feeding promoted enhanced motivation for sucrose, diminished extinction of this response and increased HFD intake in an aversive environment. The neuroendocrine and behavioral changes correlated with increased hypothalamic expression of the ghrelin receptor and FTO.

CONCLUSION

Collectively, these data indicate that patterns of feeding that include caloric overconsumption and caloric restriction induce neuroendocrine and neurobiological changes that signify an enhanced drive for palatable food.

Self-Reported Dietary Restrictions and Dietary Patterns in Polish Girls: A Short Research Report (GEBaHealth Study)

Dietary restraint is a commonly reported practice observed among young females. The practice remains controversial and can be interpreted as a beneficial self-regulating behavior or the opposite, an eating disorder that may have a detrimental effect on health. The aim of this short report was to investigate if dietary restrictions are associated with dietary patterns in a representative sample of Polish girls. Analyses were carried out on data from the Girls' Eating Behavior and Health (GEBaHealth) study. The sample included 1107 girls, ranging in age from 13 to 21 years old. Restrictions regarding food quantities and selected food groups were assessed using a standardized interview. Dietary patterns were identified with Principal Component Analysis (PCA), based on dietary data collected with Food Frequency Questionnaires (FFQs). Logistic regression analysis was used to study the associations between self-reported restrictions and each dietary pattern. In the total sample, 30.5% of girls reported following some food restrictions. The most common restrictions regarded consumption of sugar and/or sweets (23.7%), high-fat foods (22.4%), and fats (21.3%). Girls who declared following any restrictions, restrictions in food quantity and restrictions in the consumption of sugar and/or sweets, high-fat foods, fats, cereals and/or bread and/or potatoes were more likely to adhere to the "fruit and vegetables" (considered pro-healthy) dietary pattern (adjusted odds ratios (ORs): 1.55, 95% CI: 1.14-2.12; 1.61, 95% CI: 1.17-2.21; 1.81, 95% CI: 1.30-2.52; 1.46, 95% CI: 1.04-2.06; 1.96, 95% CI: 1.38-2.80 and 3.25, 95% CI: 1.97-5.37, respectively), and less likely to adhere to the "fast foods and sweets" (unhealthy) and "traditional Polish" (rather unhealthy) patterns, compared to girls who declared no restrictions. Declared restrictions in the consumption of foods high in sugar, fat, and starch were observed in girls in the "fruit and vegetables" pattern and were uncommon in girls with unhealthy dietary patterns. Although cautious interpretation is needed when considering restrictions in the overall quantity of food consumed, the results indicate that dietary restrictions of sugar, high-fat foods, fats, and starch may be considered predictors of both pro-healthy and unhealthy dietary patterns in the population of Polish girls.

Social appearance anxiety and dietary restraint as mediators between perfectionism and binge eating: A six month three wave longitudinal study

Binge eating is related to perfectionism and restrained eating. However, the mechanisms underlying these relationships are not well understood. It is possible that social anxiety, specifically social appearance anxiety (i.e., the fear of overall appearance evaluation), influences the relationship between binge eating, perfectionism, and dietary restraint. In the current study (N = 300 women), we tested the relationship between dietary restraint, social appearance anxiety, concern over mistakes (a component of perfectionism), and binge eating in prospective data (three time points: at baseline, at two month, and at six month follow up). We found that social appearance anxiety, dietary restraint, and concern over mistakes each predicted binge eating at baseline. Only social appearance anxiety prospectively predicted binge eating when accounting for all variables. Further, in the tested model, social appearance anxiety mediated the relationship between concern over mistakes and binge eating across six months. On the contrary, dietary restraint did not mediate the relationship between concern over mistakes and binge eating in the tested model. The finding that social appearance anxiety served as a mediator between concern over mistakes and binge eating, but that dietary restraint did not, implies that social appearance anxiety may be a more salient prospective predictor of binge eating than dietary restraint. Intervening on social appearance anxiety may be important in the treatment and prevention of binge eating.

Research Review: What we have learned about the causes of eating disorders - a synthesis of sociocultural, psychological, and biological research

BACKGROUND

Eating disorders are severe psychiatric disorders with a complex etiology involving transactions among sociocultural, psychological, and biological influences. Most research and reviews, however, focus on only one level of analysis. To address this gap, we provide a qualitative review and summary using an integrative biopsychosocial approach.

METHODS

We selected variables for which there were available data using integrative methodologies (e.g., twin studies, gene-environment interactions) and/or data at the biological and behavioral level (e.g., neuroimaging). Factors that met these inclusion criteria were idealization of thinness, negative emotionality, perfectionism, negative urgency, inhibitory control, cognitive inflexibility, serotonin, dopamine, ovarian hormones. Literature searches were conducted using PubMed. Variables were classified as risk factors or correlates of eating disorder diagnoses and disordered eating symptoms using Kraemer et al.'s (1997) criteria.

FINDINGS

Sociocultural idealization of thinness variables (media exposure, pressures for thinness, thin-ideal internalization, thinness expectancies) and personality traits (negative emotionality, perfectionism, negative urgency) attained 'risk status' for eating disorders and/or disordered eating symptoms. Other factors were identified as correlates of eating pathology or were not classified given limited data. Effect sizes for risk factors and correlates were generally small-to-moderate in magnitude.

CONCLUSIONS

Multiple biopsychosocial influences are implicated in eating disorders and/or disordered eating symptoms and several can now be considered established risk factors. Data suggest that psychological and environmental factors interact with and influence the expression of genetic risk to cause eating pathology. Additional studies that examine risk variables across multiple levels of analysis and that consider specific transactional processes amongst variables are needed to further elucidate the intersection of sociocultural, psychological, and biological influences on eating disorders.

DNA methylation in individuals with anorexia nervosa and in matched normal-eater controls: A genome-wide study

OBJECTIVE

Evidence associates anorexia nervosa (AN) with epigenetic alterations that could contribute to illness risk or entrenchment. We investigated the extent to which AN is associated with a distinct methylation profile compared to that seen in normal-eater women.

METHOD

Genome-wide methylation profiles, obtained using DNA from whole blood, were determined in 29 women currently ill with AN (10 with AN-restrictive type, 19 with AN-binge/purge type) and 15 normal-weight, normal-eater control women, using 450 K Illumina bead arrays.

RESULTS

Regardless of type, AN patients showed higher and less-variable global methylation patterns than controls. False Discovery Rate corrected comparisons identified 14 probes that were hypermethylated in women with AN relative to levels obtained in normal-eater controls, representing genes thought to be associated with histone acetylation, RNA modification, cholesterol storage and lipid transport, and dopamine and glutamate signaling. Age of onset was significantly associated with differential methylation in gene pathways involved in development of the brain and spinal cord, while chronicity of illness was significantly linked to differential methylation in pathways involved with synaptogenesis, neurocognitive deficits, anxiety, altered social functioning, and bowel, kidney, liver and immune function.

DISCUSSION

Although pre-existing differences cannot be ruled out, our findings are consistent with the idea of secondary alterations in methylation at genomic regions pertaining to social-emotional impairments and physical sequelae that are commonly seen in AN patients. Further investigation is needed to establish the clinical relevance of the affected genes in AN, and, importantly, reversibility of effects observed with nutritional rehabilitation and treatment.

The processing of food stimuli in abnormal eating: a systematic review of electrophysiology

To update the knowledge about attentional processing of food stimuli, a systematic review of electrophysiological studies was conducted using PubMed, PsychInfo and Web of Knowledge (2000-2014). Twenty-one studies were included into a qualitative synthesis. Presentation of food and control pictures was used to analyze event-related potentials related to sensory processing and motivated attention. Results show consistent attentional bias towards food pictures compared with neutral pictures for patient and control groups. Group comparisons between individuals with abnormal-eating and healthy-eating participants were more inconsistent. Results suggest that temporal differences in the millisecond range are essential for the understanding of visual food processing. In obesity, early attention engagement to food is followed by relatice disengagement. Loss of control eating, as well as external and emotional eating, are associated with a sustained maintenance of attention towards high-caloric food. There is a lack of studies in anorexia nervosa, bulimia nervosa and binge eating disorder.

Atitudes de nutricionistas em relação a indivíduos obesos – um estudo exploratório

O objetivo foi identificar atitudes de nutricionistas em relação à obesidade; envolvendo crenças sobre características atribuídas às pessoas obesas, fatores de desenvolvimento e a obesidade em si. Os participantes (N = 344; 97,1% mulheres) foram contatados via conselho profissional e responderam a pesquisa online. As questões do estudo foram adaptadas de trabalhos internacionais com as respostas analisadas por frequência de concordância. As respostas indicaram forte estigmatização da obesidade e preconceito contra o obeso, atribuindo características como: guloso (67,4%), não atraente (52,0%), desajeitado (55,1%), sem determinação (43,6%) e preguiçoso (42,3%). E considerando entre os mais importantes fatores causais: alterações emocionais e de humor, vício ou dependência de comida e baixa autoestima. Esta temática deve ser mais pesquisada uma vez que tais atitudes podem impactar a eficácia do tratamento; também para discussão e formação ampla sobre os significados da obesidade, e tratamento mais individualizado e humanizado para pacientes obesos.

Ovarian Hormone Influences on Dysregulated Eating: A Comparison of Associations in Women with versus without Binge Episodes

Changes in ovarian hormones predict changes in emotional eating across the menstrual cycle. However, prior studies have not examined whether the nature of associations varies across dysregulated eating severity. The current study determined whether the strength and/or nature of hormone/dysregulated eating associations differ based on the presence of clinically diagnosed binge episodes (BEs). Participants included 28 women with BEs and 417 women without BEs who provided salivary hormone samples, ratings of emotional eating, and BE frequency for 45 days. Results revealed stronger associations between dysregulated eating and ovarian hormones in women with BEs as compared to women without BEs. The nature of associations also differed, as progesterone moderated the effects of lower estradiol levels on dysregulated eating in women with BEs only. Although hormone/dysregulated eating associations are present across the spectrum of pathology, the nature of associations may vary in ways that have implications for etiological models and treatment.

The moderating role of negative urgency on the prospective association between dietary restraint and binge eating

It is well documented that negative urgency, a personality trait characterized by a tendency to act impulsively in the face of negative emotions, and dietary restraint independently increase risk to binge eat; however, it is unclear how these factors interact to alter risk for such behavior. It may be that individuals high on negative urgency, who also engage in dietary restraint, are at a greater risk to binge eat than individuals low on negative urgency. Accordingly, we sought to investigate whether negative urgency moderated the prospective association between dietary restraint and binge eating frequency among a sample of college women. We hypothesized that women who engaged in dietary restraint would report higher binge eating frequencies across the first semester of college and that this effect would be strengthened among individuals higher on negative urgency. Results indicated that negative urgency moderated the prospective association between dietary restraint and binge eating frequency. This effect was found to be "protective but reactive," such that low levels of dietary restraint protected against binge eating frequency at low to moderate levels of negative urgency, but this buffering effect was lost at high levels of negative urgency where binge eating frequency was equal across all levels of dietary restraint. These findings demonstrate that negative urgency and dietary restraint interact to differentially alter risk for binge eating frequency, and individuals high on negative urgency are at the greatest risk to engage in more frequent binge eating regardless of level of dietary restraint.

Exploring the relationship between negative urgency and dysregulated eating: etiologic associations and the role of negative affect

Negative urgency (i.e., the tendency to engage in rash action in response to negative affect) has emerged as a critical personality trait contributing to individual differences in binge eating. However, studies investigating the extent to which genetic and/or environmental influences underlie the effects of negative urgency on binge eating are lacking. Moreover, it remains unclear whether negative urgency-binge eating associations are simply a result of the well-established role of negative affect in the development/maintenance of binge eating. The current study addresses these gaps by examining phenotypic and etiologic associations between negative urgency, negative affect, and dysregulated eating (i.e., binge eating, emotional eating) in a sample of 222 same-sex female twin pairs from the Michigan State University Twin Registry. Negative urgency was significantly associated with both dysregulated eating symptoms, even after controlling for the effects of negative affect. Genetic factors accounted for the majority (62-77%) of this phenotypic association, although a significant proportion of this genetic covariation was due to genetic influences in common with negative affect. Nonshared environmental factors accounted for a relatively smaller (23-38%) proportion of the association, but these nonshared environmental effects were independent of negative affect. Findings suggest that the presence of emotion-based rash action, combined with high levels of negative affect, may significantly increase genetic risk for dysregulated eating.

Marital satisfaction and physical health: evidence for an orchid effect

Marital distress and conflict are linked to poor physical health. Here, we used behavior genetic modeling to determine the etiology of this association. Biometric moderation models were used to estimate gene-by-environment interaction in the presence of gene-environment correlation between marital satisfaction and self-reported health. Using a sample of 347 married twin pairs from the Midlife in the United States study, we found that genetic influences on the variation in self-reported health were greatest at both high (h (2) = .30) and low (h (2) = .38) levels of marital satisfaction, with the lowest levels of heritability estimated for participants at the average level of marital satisfaction (h (2) = .10). These findings are evidence of the orchid effect: the idea that genetic influences on a phenotype such as physical health are enhanced in nonnormative-both unusually positive and unusually negative-environmental contexts.

The Michigan State University Twin Registry (MSUTR): an update

The primary aim of the Michigan State University Twin Registry (MSUTR) is on understanding developmental changes in genetic, environmental, and neurobiological influences on internalizing and externalizing disorders, with antisocial behavior and disordered eating representing our particular areas of interest. The MSUTR has two broad components: a large-scale, population-based registry of child, adolescent, and adult twins and their families (current N ~20,000) and a series of more focused and in-depth studies drawn from the registry (current N ~4,000). Participants in the population-based registry complete a family health and demographic questionnaire via mail. Families are then recruited for one or more of the intensive, in-person studies from the population-based registry based on their answers to relevant items in the registry questionnaire. These in-person assessments target a variety of biological, genetic, and environmental phenotypes, including multi-informant measures of psychiatric and behavioral phenotypes, census and neighborhood informant reports of twin neighborhood characteristics, buccal swab and salivary DNA samples, assays of adolescent and adult steroid hormone levels, and/or videotaped interactions of child twin families. This article provides an overview of the MSUTR and describes current and future research directions.

Physical activity as a moderator of the association between anxiety sensitivity and binge eating

Individuals with elevated anxiety sensitivity (AS; i.e., fear of somatic arousal) may binge eat to reduce emotional distress. Because physical activity reduces stress reactivity, we predicted that: (1) the relation between AS and binge eating would be moderated by physical activity and (2) coping motives for eating would mediate the association between AS and binge eating such that the relation would be stronger for those low in physical activity. Participants (N=167) completed online self-report measures. Regression analyses revealed that moderate-intensity physical activity (MPA) moderated the relation between AS and binge eating such that AS was not related to binge eating among those who frequently engaged in MPA but was related to binge eating among those who did not report engaging in MPA. Vigorous-intensity physical activity (VPA) moderated in the opposite direction such that the relation between AS and binge eating was significant among persons reporting high levels of VPA but less strong among persons reporting low levels of VPA. The mediation model was also significant, but was not moderated by MPA or VPA. Theoretical and clinical implications are discussed.

A debate on current eating disorder diagnoses in light of neurobiological findings: is it time for a spectrum model?

BACKGROUND

Sixty percent of eating disorders do not meet criteria for anorexia- or bulimia nervosa, as defined by the Diagnostic and Statistical Manual version 4 (DSM-IV). Instead they are diagnosed as 'eating disorders not otherwise specified' (EDNOS). Discrepancies between criteria and clinical reality currently hampering eating disorder diagnoses in the DSM-IV will be addressed by the forthcoming DSM-V. However, future diagnoses for eating disorders will rely on current advances in the fields of neuroimaging and genetics for classification of symptoms that will ultimately improve treatment.

DISCUSSION

Here we debate the classification issues, and discuss how brain imaging and genetic discoveries might be interwoven into a model of eating disorders to provide better classification and treatment. The debate concerns: a) current issues in the classification of eating disorders in the DSM-IV, b) changes proposed for DSM-V, c) neuroimaging eating disorder research and d) genetic eating disorder research.

SUMMARY

We outline a novel evidence-based 'impulse control' spectrum model of eating disorders. A model of eating disorders is proposed that will aid future diagnosis of symptoms, coinciding with contemporary suggestions by clinicians and the proposed changes due to be published in the DSM-V.

Interaction of the BcII glucocorticoid receptor polymorphism and childhood abuse in Bulimia Nervosa (BN): relationship to BN and to associated trait manifestations

We recently documented a gene-environment interaction suggesting that individuals with Bulimia Nervosa (BN) differed from normal eaters as to the combined presence of the low-function allele of the glucocorticoid receptor polymorphism, BcII, and childhood abuse. The present study examined the extent to which any such interaction effect may have been attributable to behavioral impulsivity, sensation seeking, affective instability or depression. We had 174 bulimic and 130 nonbulimic women provide blood for genetic assays, and measured psychopathological traits and childhood abuse using structured interviews and self-report questionnaires. As expected, we observed a significant BcII × abuse interaction indicating genetic and environmental susceptibilities to co-occur significantly more often in bulimic than in nonbulimic individuals. The BcII × abuse interaction was attenuated when levels of depression were accounted for, but was surprisingly unaffected by controls for motoric impulsivity, sensation seeking or affective instability. Our findings suggest that stress-induced alterations in glucocorticoid sensitivity contribute to BN and depressive disturbances--without being associated with the behavioral/affective dysregulation seen in many BN sufferers. We discuss theoretical and clinical implications of these observations.