Stress response and binge eating disorder

Reduced plasma interleukin-6 concentration after transcranial direct current stimulation to the prefrontal cortex

OBJECTIVES

Transcranial direct stimulation (tDCS) targeted to the dorsolateral prefrontal cortex (DLPFC) reduces food intake and hunger, but its effects on circulating factors are unclear. We assessed the effect of repeated administration of tDCS to the left DLPFC (L-DLPFC) on concentrations of pro/anti-inflammatory and appetitive hormone concentrations.

MATERIALS AND METHODS

Twenty-nine healthy adults with obesity (12 M; 42±11 y; BMI=39±8 kg/m2) received 3 consecutive inpatient sessions of either anodal or sham tDCS targeted to the L-DLPFC during a period of ad libitum food intake. Fasting plasma concentrations of IL-6, orexin, cortisol, TNF-α, IL-1β, ghrelin, PYY, and GLP-1 were measured before the initial and after the final tDCS sessions.

RESULTS

IL-6 (β=-0.92 pg/ml p=0.03) decreased in the anodal group compared with sham, even after adjusting for kcal intake; there were no changes in other hormones. Mean kcal intake was associated with higher IL-1β and ghrelin concentrations after the ad libitum period (β=0.00018 pg/ml/kcal, p=0.03; β=0.00011 pg/ml/kcal, p=0.02; respectively), but not differ by intervention groups.

CONCLUSIONS

IL-6 concentrations were reduced following anodal tDCS to the L-DLPFC independent of ad libitum intake. IL-6 concentrations reflect the inflammatory state of adiposity and may affect eating behavior and weight gain. These findings provide evidence of therapeutic benefit of tDCS.

Food insecurity and binge-eating disorder in early adolescence

OBJECTIVE

Food insecurity is defined as lack of consistent access to adequate food for healthy living. The objective of this study was to determine the associations between food insecurity and binge-eating disorder in a national cohort of 9- to 14-year-old children.

METHOD

We analyzed prospective cohort data from the Adolescent Brain Cognitive Development (ABCD) Study (N = 10,035, 2016-2020). Logistic regression analyses estimated the associations between food insecurity at baseline, year 1, or year 2 (exposure) and binge eating, subclinical binge-eating disorder (Other Specified Feeding and Eating Disorder-Binge-Eating Disorder [OSFED-BED]), and binge-eating disorder (BED) (outcome) based on the Kiddie Schedule for Affective Disorders and Schizophrenia (KSADS-5) at 2-year follow-up.

RESULTS

The prevalence of food insecurity in the study was 15.8%. At 2-year follow-up, 1.71% of the sample received a diagnosis of BED or OSFED-BED, while 6.62% reported binge eating. Food insecurity was associated with 1.67 higher odds of BED or OSFED-BED (95% CI 1.04-2.69) and 1.31 higher odds of binge-eating symptoms (95% CI 1.01-1.71).

DISCUSSION

Food insecurity in early adolescence is associated with higher odds of developing future binge-eating and BED or OSFED-BED. Clinicians may consider assessing for binge eating in adolescents with food insecurity and provide support in accessing appropriate food resources.

PUBLIC SIGNIFICANCE

Prior research has shown that food insecurity is associated with disordered eating behaviors, including binge eating in adulthood. This study explored whether food insecurity in early adolescence increases risk for developing binge-eating disorder (BED). Targeted screening for BED in adolescents experiencing FI, and vice versa, may be warranted.

The role of stress in the association among food insecurity, eating disorder pathology, and binge eating-related appetitive traits

PURPOSE

Growing literature demonstrates a positive association between food insecurity (FI) and eating disorder pathology. Additionally, FI has been associated with two appetitive traits strongly linked to binge eating, food responsiveness and emotional overeating. However, little research has investigated factors that might help to explain these associations. One hypothesis is that experiencing FI may increase stress, and that eating disorder pathology, particularly binge eating-related phenotypes, may serve as a coping strategy. This study explores stress as a potential mechanism in the association between FI and general eating disorder pathology, as well as two appetitive traits strongly associated with binge eating (food responsiveness and emotional overeating).

METHODS

Cis-gender women (N = 634) completed online questionnaires assessing FI, stress, eating disorder pathology (measured via the total score on the Short Eating Disorder Examination Questionnaire), and binge eating-related appetitive traits (measured via the Adult Eating Behavior Questionnaire). Cross-sectional indirect effects analyses with a 1000-sample bootstrap were used to test pathways among FI, stress, and eating-related constructs.

RESULTS

FI was significantly associated with eating disorder pathology and associated appetitive traits (ps < 0.001). Stress explained a significant proportion of the correlation between FI and each eating-related construct.

CONCLUSIONS

Our findings extend prior research on the relationships between FI, eating disorder pathology, and binge eating-related appetitive traits to provide preliminary evidence that stress may act as an underlying mechanism. Future studies should use longitudinal designs to assess the prospective relationships among these constructs.

Sex-dependent role of orexin deficiency in feeding behavior and affective state of mice following intermittent access to a Western diet - Implications for binge-like eating behavior

Binge eating disorder is a debilitating disease characterized by recurrent episodes of excessive food consumption and associated with psychiatric comorbidities. Despite a growing body of research investigating the neurobiological underpinnings of eating disorders, specific treatments are lacking. Given its fundamental role in feeding behaviors, we investigated the role of the orexin (hypocretin) neuropeptide system in binge-like eating and associated phenotypes. Specifically, we submitted female and male orexin-deficient mice to a paradigm of intermittent access (once weekly for 24 h) to a Western diet (WD) to induce binge-like eating. Additionally, we measured their anxiety-like behavior and plasma corticosterone levels. All mice showed binge-like eating in response to the intermittent WD access, but females did so to a greater extent than males. While orexin deficiency did not affect binge-like eating in this paradigm, we found that female orexin-deficient mice generally weighed more, and they expressed increased hypophagia and stress levels compared to wild-type mice following binge-like eating episodes. These detrimental effects of orexin deficiency were marginal or absent in males. Moreover, male wild-type mice expressed post-binge anxiety, but orexin-deficient mice did not. In conclusion, these results extend our knowledge of orexin's role in dysregulated eating and associated negative affective states, and contribute to the growing body of evidence indicating a sexual dimorphism of the orexin system. Considering that many human disorders, and especially eating disorders, have a strong sex bias, our findings further emphasize the importance of testing both female and male subjects.

Prefrontal cortical protease TACE/ADAM17 is involved in neuroinflammation and stress-related eating alterations

Childhood traumatic stress profoundly affects prefrontal cortical networks regulating top-down control of eating and body weight. However, the neurobiological mechanisms contributing to trauma-induced aberrant eating behaviors remain largely unknown. Traumatic stress influences brain immune responses, which may, in turn, disrupt prefrontal cortical networks and behaviors. The tumor necrosis factor alpha-converting enzyme / a disintegrin and metalloproteinase 17 (TACE/ADAM17) is a sheddase with essential functions in brain maturation, behavior, and neuroinflammation. This study aimed to determine the role of TACE/ADAM17 on traumatic stress-induced disruption of eating patterns. We demonstrate a novel mechanistic connection between prefrontal cortical TACE/ADAM17 and trauma-induced eating behaviors. Fifty-two (52) adolescent Lewis rats (postnatal day, PND, 15) were injected intracerebrally either with a novel Accell™ SMARTpool ADAM17 siRNA or a corresponding siRNA vehicle. The RNAscope Multiplex Fluorescent v2 Assay was used to visualize mRNA expression. Observation cages were used to monitor ethological behaviors in a more naturalistic environment over long periods. We found that traumatic stress blunts startle reactivity and alter eating behaviors (increased intake and disrupted eating patterns). We also found that the rats that received prefrontal cortical TACE/ADAM17 siRNA administration exhibited decreased eating and increased grooming behaviors compared to controls. These changes were associated with decreased AIF-1 expression (a typical marker of microglia and neuroinflammation). This study demonstrates that prefrontal cortical TACE/ADAM17 is involved in neuroinflammation and may play essential roles in regulating feeding patterns under stress conditions. TACE/ADAM17 represents a promising target to ameliorate inflammation-induced brain and behavior alterations.

Obesity and acute stress modulate appetite and neural responses in food word reactivity task

Obesity can result from excess intake in response to environmental food cues, and stress can drive greater intake and body weight. We used a novel fMRI task to explore how obesity and stress influenced appetitive responses to relatively minimal food cues (words representing food items, presented similarly to a chalkboard menu). Twenty-nine adults (16F, 13M), 17 of whom had obesity and 12 of whom were lean, completed two fMRI scans, one following a combined social and physiological stressor and the other following a control task. A food word reactivity task assessed subjective food approach (wanting) as well as food avoidant (restraint) responses, along with neural responses, to words denoting high energy-density (ED) foods, low-ED foods, and non-foods. A multi-item ad-libitum meal followed each scan. The obese and lean groups demonstrated differences as well as similarities in activation of appetitive and attention/self-regulation systems in response to food vs. non-food, and to high-ED vs. low-ED food words. Patterns of activation were largely similar across stress and non-stress conditions, with some evidence for differences between conditions within both obese and lean groups. The obese group ate more than the lean group in both conditions. Our results suggest that neural responses to minimal food cues in stressed and non-stressed states may contribute to excess consumption and adiposity.

Assessment of Risk Factors for Development of Overweight and Obesity among Soldiers of Polish Armed Forces Participating in the National Health Programme 2016-2020

The aim of this study was to assess the prevalence of overweight and obesity among Polish Armed Forces soldiers and to analyze risk factors impacting body mass. In total, 1096 male, Caucasian soldiers (36.31 ± 8.03 years) participated in this study. Anthropometric data were obtained, and questionnaires evaluated sociodemographic, environmental, behavioral and biological factors known to be associated with obesity. Only 33% of the total number of participants had normal body weight, and 17.3% were considered obese (according to WHO criteria). The results showed that being 40 years or older, sleeping six hours or less per day, more frequent reaching for food in stressful situations, having a mother with excessive body weight, not exercising or exercising at most two days per week, and spending two hours a day or more in front of the TV increase the risk of obesity. Taken together, the results show that factors such as family history of obesity, dietary habits, physical activity, length of sleep and ability to cope with stress could be used to identify soldiers at higher risk of developing obesity in order to provide them with personalized prevention programs.

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

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

Bridging gaps by including culture: Development and empirical test of the culturally informed theory for disordered eating among Black women

BACKGROUND

Leading eating disorder (ED) theories were informed primarily by samples of White females. Therefore, ED theories lack consideration of sociocultural factors that may impact ED symptom development among Black women. The current study proposed the first culturally informed theory for disordered eating among Black women, positing that ethnic discrimination, strong black woman (SBW) ideology (cultural and societal expectations of strength), and culturally informed appearance satisfaction may significantly impact stress. Stress may be associated with coping-motivated eating behaviors, which may lead to maladaptive weight control behaviors.

METHODS

Black women (N = 208) completed surveys assessing socio-cultural factors, stress, commensal and binge eating, and maladaptive weight control behaviors. Path analysis was used to test the proposed theory.

RESULTS

The final model had a good fit for the data. Findings overall supported the hypothesized model. Specifically, higher ethnic discrimination (β = 0.044, p = .003), greater endorsement of SBW ideology (β = 0.074, p =< .001), and lower culturally informed appearance satisfaction (β = -0.032, p = .025) were associated with greater stress. Stress was positively associated with binge eating (β = 0.457, p = .046), and binge eating was significantly associated with excessive exercise (=0.152, p = .008) and purging (β = 0.273, p = <.001). In contrast, commensal eating was not associated with stress or weight control behaviors (p values = .697 to .749).

CONCLUSIONS

The current study found that stress, as influenced by sociocultural factors, may play a role in binge eating, and subsequently, weight control behaviors among Black women. This theory is a starting point for future research on the specialized conceptualization of eating and maladaptive weight control behaviors among Black women.

The association between binge eating disorder and weight management in overweight and obese adults: A systematic literature review

Aim: Weight loss is shown to improve obesity-related health problems as long as it is maintained for a long term. The purpose of this systematic review was to investigate the association between binge eating disorder and weight management in overweight and obese adults. Methods: A systematic search following the preferred reporting items for systematic reviews and meta-analyses guidelines was conducted across PubMed, Ebsco and Cochrane Library from inception through December 2020 to identify studies that assessed the association between binge eating disorder and weight management (e.g., weight loss, weight gain and weight loss maintenance) in overweight and obese adults. We included studies that examined adults (≥18 years old) being overweight and obese with and without binge eating behaviour. Two authors independently screened and evaluated studies for methodological quality. Results: Nine articles were selected, including 3685 participants. Three of the included studies were randomised control trials and the remaining were observational studies. The majority of the studies included support that people who have binge eating disorder may have an additional barrier maintaining their weight loss compared to people who do not suffer from binge eating disorder. Conclusion: Our systematic review revealed that binge eating disorder may have a negative association with weight loss maintenance. Further well-conducted prospective cohort studies and randomised clinical trials are required to investigate the possible mechanisms and whether any such mechanisms are modifiable. These will lead us to more efficient strategies targeting weight management.

Hypothalamic-pituitary-adrenal axis attenuation and obesity risk in sexually abused females

BACKGROUND

Childhood sexual abuse (CSA) confers elevated risks for obesity in females. Mechanisms that explain this link remain unclear. This study tracked serum basal cortisol levels with body mass index (BMI) from childhood into adulthood to test whether hypothalamic-pituitary-adrenal (HPA) axis attenuation accounts for elevated obesity risks for sexually abused females.

METHODS

Data drew from six timepoints of a longitudinal study of the impact of CSA on development. Participants were females aged 6-16 years at time of study enrollment with substantiated CSA and demographically matched non-abused peers. Analyses included only participants who did not have obesity at study enrollment. Main outcomes were BMI growth trajectories across ages 6-27 (n = 150; 66 abused, 84 comparisons) and early adulthood obesity status (ages 20-27; n = 133; 62 abused, 71 comparison). HPA axis functioning indicators were intercept and linear slope parameters extracted from multilevel growth trajectories of serum basal cortisol levels across development. Racial-ethnic minority status, parity, steroid medication use, depression history and disordered eating history were covaried.

RESULTS

While controlling for covariates, multilevel modeling indicated that high initial serum basal cortisol levels in childhood and attenuated cortisol growth rate over time (i.e., HPA axis attenuation) were associated with accelerated BMI accumulation (p < .01). Attenuated cortisol growth rate mediated the effect of CSA on accelerated BMI accumulation and on elevated adulthood obesity rates (p < .05).

CONCLUSION

This work establishes a mechanistic association between HPA axis attenuation and obesity, suggesting that trauma treatments for abuse survivors should include interventions that reduce health consequences associated with dysregulated stress physiology.

The role of the intestinal microbiota in eating disorders - bulimia nervosa and binge eating disorder

Bulimia nervosa (BN) and binge eating disorder (BED) are both eating disorders (EDs) characterised by episodes of overeating in which large amounts of food are consumed in short periods. The aetiology of BN and BED is not fully understood. Psychological and social factors influence the development of BN and BED, but biological factors such as neurohormones that regulate hunger and satiety, or neurotransmitters responsible for mood and anxiety play a significant role in sustaining symptoms. Increasing numbers of studies confirm the relationship between the composition of intestinal microbiota and the regulation of appetite, mood, and body mass. In this manuscript, we will describe the mechanisms by which intestinal dysbiosis can play an important role in the aetiology of binge eating episodes based on current understanding. Understanding the two-way relationship between BN and BED and alterations in the intestinal microbiota suggest the utility of new treatment methods of these disorders aimed at improving the composition of the intestinal microflora.

COVID-19 Stress and Food Intake: Protective and Risk Factors for Stress-Related Palatable Food Intake in U.S. Adults

(1) Background: The coronavirus (COVID-19) pandemic has caused disruptions to what people eat, but the pandemic's impact on diet varies between individuals. The goal of our study was to test whether pandemic-related stress was associated with food intake, and whether relationships between stress and intake were modified by appetitive and cognitive traits. (2) Methods: We cross-sectionally surveyed 428 adults to examine current intake frequency of various food types (sweets/desserts, savory snacks, fast food, fruits, and vegetables), changes to food intake during the pandemic, emotional overeating (EOE), cognitive flexibility (CF), and COVID-19-related stress. Models tested associations of stress, EOE, and CF with food intake frequency and changes to intake. (3) Results: Models demonstrated that the positive relationship between stress and intake of sweets/desserts was stronger with higher EOE, while the positive relationship between stress and intake of chips/savory snacks was weaker with higher CF. Higher EOE was associated with greater risk of increased intake of palatable foods. (4) Conclusions: Findings suggest that emotional overeating may escalate stress-associated intake of high-sugar foods, and cognitive flexibility may attenuate stress-associated intake of high-fat foods. Differences in appetitive and cognitive traits may explain changes to and variability in food intake during COVID-19, and efforts to decrease emotional overeating and encourage cognitive flexibility could help lessen the effect of COVID-19-related stress on energy dense food intake.

The controlling role of nitric oxide within the shell of nucleus accumbens in the stress-induced metabolic disturbance

CONTEXT AND OBJECTIVES

The involvement of the nitricergic system within the shell part of the nucleus accumbens (NAc) was evaluated in the metabolic disturbances due to stress.

MATERIALS AND METHODS

Male Wistar rats were cannulated in the shell of the left NAc. They received either saline or different doses of L-arginine and/or L-NAME five minutes before each stress session, for four days. Plasma cortisol concentration, food and water intake, time elapsing for eating, animal weight changes and adrenal gland weight were recorded.

RESULTS

The L-arginine 1 μg/rat decreased the level of cortisol, water and food intake and time of feeding and increased the adrenal weight. But L-NAME at 1 μg/rat had opposite effects on these factors. However, the drugs showed similar effects at 10 μg/rat.

CONCLUSION

Injection of nitric oxide modifiers into the left side of NAc shell part may have an interactive role with sub-chronic stress in metabolic behaviour.

Psychosocial, Lifestyle, and Body Weight Impact of COVID-19-Related Lockdown in a Sample of Participants with Current or Past History of Obesity in Spain

Purpose

Home lockdown and isolation due to COVID-19 have been related to negative changes in mood, sleep, and eating behaviors. People with obesity are especially vulnerable to emotional eating and might be more prone to weight gain and negative outcomes during lockdown.

Materials and Methods

Individuals scheduled for an appointment at the Obesity Unit of a Tertiary Hospital between March 16 and June 21 (n=1230). An online survey was distributed on May 11. Multivariable logistic regression models and general linear models were used to assess the relationship between perceived COVID-19 threat, BS status, and outcome variables.

Results

Of the 603 (72.0% females, 39% aged >55 years) respondents, 223 (36.9%) were BS naïve (non-BS), 134 (22.2%) underwent BS within the two previous years (BS<2y), and 245 (40.6%) more than 2 years before (BS>2y). Participants worried about being infected by COVID-19 showed significantly larger changes in family contact (p=0.04), mood (p<0.01), sleep (p<0.01), dietary habits (p=0.05), purchases of unhealthy food (p=0.02), snacking (p=0.05), and physical activity (p=0.02). Non-BS and BS>2y participants reported greater impact of lockdown in mood (p<0.01), experienced more negative changes in dietary habits (p<0.01), and had a higher likelihood for weight gain (OR: 5.61, 95% CI: 3.0–10.46; OR: 5.45, 95% CI: 2.87–10.35, respectively) compared to BS<2y.

Conclusions

COVID-19 pandemic is having a substantial negative impact in our population affected by obesity. During lockdown, people more than 2 years before BS behave like people without history of BS. Strategies addressed to prevent negative metabolic outcomes in this population are urgently needed.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11695-021-05225-z.

The Neurobiology of Binge-eating Disorder Compared with Obesity: Implications for Differential Therapeutics

PURPOSE

Emerging work indicates divergence in the neurobiologies of binge-eating disorder (BED) and obesity despite their frequent co-occurrence. This review highlights specific distinguishing aspects of BED, including elevated impulsivity and compulsivity possibly involving the mesocorticolimbic dopamine system, and discusses implications for differential therapeutics for BED.

METHODS

This narrative review describes epidemiologic, clinical, genetic, and preclinical differences between BED and obesity. Subsequently, this review discusses human neuroimaging work reporting differences in executive functioning, reward processing, and emotion reactivity in BED compared with obesity. Finally, on the basis of the neurobiology of BED, this review identifies existing and new therapeutic agents that may be most promising given their specific targets based on putative mechanisms of action relevant specifically to BED.

FINDINGS

BED is characterized by elevated impulsivity and compulsivity compared with obesity, which is reflected in divergent neurobiological characteristics and effective pharmacotherapies. Therapeutic agents that influence both reward and executive function systems may be especially effective for BED.

IMPLICATIONS

Greater attention to impulsivity/compulsivity-related, reward-related, and emotion reactivity-related processes may enhance conceptualization and treatment approaches for patients with BED. Consideration of these distinguishing characteristics and processes could have implications for more targeted pharmacologic treatment research and interventions.

Deletion of mu opioid receptors reduces palatable solution intake in a mouse model of binge eating

Binge eating in humans is driven by hedonic properties of food, suggesting that brain reward systems may contribute to this behaviour. We examined the role of mu opioid receptors (MOP) in binge eating by examining sweet solution intake in mice with genetic deletion of the MOP. Wildtype and MOP knockout mice had 4 hours access to food in the home cage combined with limited (4 hours) access to sucrose (17.1% w/v) or saccharin (0.09% w/v), or continuous (24 hours) access to sucrose. Only limited access groups exhibited binge intake, measured as increased solution consumption during the first hour. Knockout mice consumed less solution and food during the first hour as well as less food each day compared with wildtype mice. Limited access groups consumed more food and gained more weight than continuous access groups, and the effect was magnified in saccharin-consuming mice. Indeed, the increased food consumption in animals given limited access to saccharin was so excessive that caloric intake of this group was significantly higher than either of the sucrose groups (limited or continuous access). Within this group, females consumed more food per bodyweight than males, highlighting important sex differences in feeding behaviours under restricted access schedules.

Unhealthy eating and academic stress: The moderating effect of eating style and BMI

This study aimed to evaluate the relationship between stress and unhealthy eating among undergraduate students, considering the moderation effects of BMI, eating style, and nationality. A total of 748 Italian and French students completed self-report measures of academic stress, emotional eating, restrained eating, BMI, and unhealthy eating intake. Results showed that academic stress increased unhealthy food consumption in Italian students, whereas it reduced junk food consumption in French students. Negative emotional eating and BMI moderated, respectively, the impact of academic stress on sweet food intake and snacking. Finally, no clear support was found for the moderation role of restrained eating.

Binge-like palatable food intake in rats reduces preproglucagon in the nucleus tractus solitarius

Binge eating involves eating larger than normal quantities of food within a discrete period of time. The neurohormonal controls governing binge-like palatable food intake are not well understood. Glucagon-like peptide-1 (GLP-1), a hormone produced peripherally in the intestine and centrally in the nucleus tractus solitarius (NTS), reduces food intake. Given that the NTS plays a critical role in integrating peripheral and central signals relevant for food intake, as well as the role of GLP-1 in motivated feeding, we tested the hypothesis that expression of the GLP-1 precursor preproglucagon (PPG) would be reduced in the NTS of rats with a history of binge-like palatable food intake. Adult male rats received access to fat for 1 h shortly before lights off, either every day (Daily, D) or only 3d/week (Intermittent, INT). INT rats ate significantly more fat than did D rats in sessions where all rats had fat access. After ~8.5 weeks of diet maintenance, we measured plasma GLP-1 as well as NTS PPG and GLP-1 receptor expression. INT rats had significantly lower NTS PPG mRNA expression compared to D rats. However, plasma GLP-1 was significantly increased in the INT group versus D rats. No significant differences were observed in NTS GLP-1 receptor expression. We also measured plasma insulin levels, fasted blood glucose, and plasma corticosterone but no differences were detected between groups. These results support the hypothesis that binge-like eating reduces NTS GLP-1 expression, and furthermore, demonstrate divergent impacts of binge-like eating on peripheral (plasma) versus central GLP-1.

Associations between Family Weight-Based Teasing, Eating Pathology, and Psychosocial Functioning among Adolescent Military Dependents

Weight-based teasing (WBT) by family members is commonly reported among youth and is associated with eating and mood-related psychopathology. Military dependents may be particularly vulnerable to family WBT and its sequelae due to factors associated with their parents' careers, such as weight and fitness standards and an emphasis on maintaining one's military appearance; however, no studies to date have examined family WBT and its associations within this population. Therefore, adolescent military dependents at-risk for adult obesity and binge-eating disorder were studied prior to entry in a weight gain prevention trial. Youth completed items from the Weight-Based Victimization Scale (to assess WBT by parents and/or siblings) and measures of psychosocial functioning, including the Beck Depression Inventory-II, The Rosenberg Self-Esteem Scale, and the Social Adjustment Scale. Eating pathology was assessed via the Eating Disorder Examination interview, and height and fasting weight were measured to calculate BMIz. Analyses of covariance, adjusting for relevant covariates including BMIz, were conducted to assess relationships between family WBT, eating pathology, and psychosocial functioning. Participants were 128 adolescent military dependents (mean age: 14.35 years old, 54% female, 42% non-Hispanic White, mean BMIz: 1.95). Nearly half the sample (47.7%) reported family WBT. Adjusting for covariates, including BMIz, family WBT was associated with greater eating pathology, poorer social functioning and self-esteem, and more depressive symptoms (ps ≤ 0.02). Among military dependents with overweight and obesity, family WBT is prevalent and may be linked with eating pathology and impaired psychosocial functioning; prospective research is needed to elucidate the temporal nature of these associations.

Neuroendocrinology of reward in anorexia nervosa and bulimia nervosa: Beyond leptin and ghrelin

The pathophysiology of anorexia nervosa (AN) and bulimia nervosa (BN) are still poorly understood, but psychobiological models have proposed a key role for disturbances in the neuroendocrines that signal hunger and satiety and maintain energy homeostasis. Mounting evidence suggests that many neuroendocrines involved in the regulation of homeostasis and body weight also play integral roles in food reward valuation and learning via their interactions with the mesolimbic dopamine system. Neuroimaging data have associated altered brain reward responses in this system with the dietary restriction and binge eating and purging characteristic of AN and BN. Thus, neuroendocrine dysfunction may contribute to or perpetuate eating disorder symptoms via effects on reward circuitry. This narrative review focuses on reward-related neuroendocrines that are altered in eating disorder populations, including peptide YY, insulin, stress and gonadal hormones, and orexins. We provide an overview of the animal and human literature implicating these neuroendocrines in dopaminergic reward processes and discuss their potential relevance to eating disorder symptomatology and treatment.

The potential of calibrated fMRI in the understanding of stress in eating disorders

Eating disorders (ED), including Anorexia Nervosa (AN), Bulimia Nervosa (BN), and Binge Eating Disorder (BED), are medically dangerous psychiatric disorders of unknown etiology. Accumulating evidence supports a biopsychosocial model that includes genetic heritability, neurobiological vulnerability, and psychosocial factors, such as stress, in the development and maintenance of ED. Notably, stress hormones influence appetite and eating, and dysfunction of the physiological stress response has been implicated in ED pathophysiology. Stress signals also appear associated with food reward neurocircuitry response in ED, providing a possible mechanism for the role of stress in appetite dysregulation. This paper provides a review of some of the interacting psychological, behavioral, physiological, and neurobiological mechanisms involved in the stress response among individuals with ED, and discusses novel neuroimaging techniques to address potential physiological confounds of studying neural correlates of stress in ED, such as calibrated fMRI.

Sedentariness and Health: Is Sedentary Behavior More Than Just Physical Inactivity?

Sedentary behavior refers to certain activities in a reclining, seated, or lying position requiring very low energy expenditure. It has been suggested to be distinct from physical inactivity and an independent predictor of metabolic risk even if an individual meets current physical activity guidelines. Over the past decades, a shift in the activity profile of individuals has been observed with vigorous physical activity and sleep being partly replaced by cognitive work, a potential neurogenic stress component considering its hormonal and neurophysiological effects, leading to various impacts on health. Mental work, for instance, may significantly increase glycemic instability leading to an increase in the desire to eat and thus, higher energy intakes. Furthermore, screen-based leisure activities (e.g., television watching) and screen-based work activities (e.g., computer use for work purposes) have often been considered together while they may not trigger the same stress response and/or use of substrate. Thus, the problems of sedentariness may not only be attributed to a lack of movement, but also to the stimulation provided by replacing activities. The objective of this review is to discuss the (1) recent evidence and current state of knowledge regarding the health impact of sedentary behaviors on health; (2) potential neurogenic effects of cognitive work as a sedentary behavior; (3) link between sedentary behaviors and the diet; (4) resemblance between sedentary behaviors and the inadequate sleeper; and (5) potential solutions to reduce sedentary behaviors and increase physical activity.

Why I eat at night: A qualitative exploration of the development, maintenance and consequences of Night Eating Syndrome

Night Eating Syndrome (NES), as a diagnosis, presents as a combination of disordered eating, sleep and mood. Patients identified as having both NES and obesity demonstrate poorer outcomes in terms of weight loss compared to those with NES only. However, research focusing on psychological factors associated with NES remains relatively underdeveloped. This study aimed to explore the relationship between NES and the experience of emotion from the perspective of patients accessing a weight management service. Ten adults who met diagnostic criteria for moderate or full NES took part in a semi-structured interview. Data were analysed using a constructivist approach to grounded theory. A core concept to emerge from the analysis was termed 'emotional hunger'; reflecting an urge or need to satiate a set of underlying unmet emotional needs. It was underpinned by the following interrelated themes: (1) Cultivating a dependency on food; (2) Relying on food to regulate emotions; (3) Understanding the significance of night-time; (4) Acknowledging the consequences of night eating. This study provides an in-depth understanding of the relationship between NES and the experience of emotion from the perspective of patients attending a weight management service. Results have potential to inform future service development, particularly around the adoption of a more holistic approach to night eating behaviours.

Mood and restrained eating moderate food-associated response inhibition in obese individuals with binge eating disorder

Recent research suggests that obese individuals with binge eating disorder (BED) show deficits in response inhibition, but findings are not consistent, especially when food-associated stimuli are presented. The aim of the present study was to assess the role of moderating factors by taking into account restrained eating and mood. Seventeen obese women with BED, 20 obese women without BED and 20 normal-weight controls (NW) were recruited. A go/no-go task with food-associated and control stimuli and questionnaires were administered. Obese BED showed less impairment of response inhibition to food-associated than to control stimuli, while this pattern was reversed in NW; no differences were observed for obese participants. Interestingly, group differences were moderated by the interaction of restrained eating and mood, and obese BED made the most commission errors to food-associated stimuli when they were restrained eaters and in a very positive mood at the time of testing. Our results might explain why some studies did not observe deficits in response inhibition to food-associated cues in BED.

Perceived Discrimination and Binge Eating Disorder; Gender Difference in African Americans

Environmental stressors, such as perceived discrimination (PD), are linked to Binge Eating Disorder (BED). The current study investigated the association between PD and BED among African Americans, and the variation in such an association based on gender. Data of the National Survey of American Life (NSAL), 2001⁻2003, with a nationally-representative sample of African American adults, were used (n = 3516). The independent variable in the study was PD. The dependent variable was BED, measured using the Composite International Diagnostic Interview (CIDI). Socio-demographics (age, education, employment, and marital status) were covariates, and gender was the moderator variable. Survey logistic regressions with and without gender × PD interaction terms were used for data analysis. In the pooled sample, PD was associated with higher odds of BED, net of socio-demographic factors. Models also showed a significant gender × PD interaction term suggesting a stronger association between PD and BED for women, compared to men. Gender specific models showed an association between PD and BED among female, but not male, African Americans. Although a link may exist between PD and BED among African Americans, the magnitude of this association depends on gender, with a stronger association among females than males. This finding is in line with the literature that has shown gender-specific consequences of environmental stress for African Americans.

Men Respond Too: The Effects of a Social-Evaluative Body Image Threat on Shame and Cortisol in University Men

Framed within social self-preservation theory, the present study investigated men's psychobiological responses to social-evaluative body image threats. University men ( n = 66) were randomly assigned to either a high or low social-evaluative body image threat condition. Participants provided saliva samples (to assess cortisol) and completed measures of state body shame prior to and following their condition, during which anthropometric and strength measures were assessed. Baseline corrected values indicated men in the high social-evaluative body image threat condition had higher body shame and cortisol than men in the low social-evaluative body image threat condition. These findings suggest that social evaluation in the context of situations that threaten body image leads to potentially negative psychobiological responses in college men.

Role of addiction and stress neurobiology on food intake and obesity

The US remains at the forefront of a global obesity epidemic with a significant negative impact on public health. While it is well known that a balance between energy intake and expenditure is homeostatically regulated to control weight, growing evidence points to multifactorial social, neurobehavioral and metabolic determinants of food intake that influence obesity risk. This review presents factors such as the ubiquitous presence of rewarding foods in the environment and increased salience of such foods that stimulate brain reward motivation and stress circuits to influence eating behaviors. These rewarding foods via conditioned and reinforcing effects stimulate not only metabolic, but also stress hormones, that, in turn, hijack the brain emotional (limbic) and motivational (striatal) pathways, to promote food craving and excessive food intake. Furthermore, the impact of high levels of stress and trauma and altered metabolic environment (e.g. higher weight, altered insulin sensitivity) on prefrontal cortical self-control processes that regulate emotional, motivational and visceral homeostatic mechanisms of food intake and obesity risk are also discussed. A heuristic framework is presented in which the interactive dynamic effects of neurobehavioral adaptations in metabolic, motivation and stress neurobiology may further support food craving, excessive food intake and weight gain in a complex feed-forward manner. Implications of such adaptations in brain addictive-motivational and stress pathways and their effects on excessive food intake and weight gain are discussed to highlight key questions that requires future research attention in order to better understand and address the growing obesity epidemic.

The Identity Threat of Weight Stigma in Adolescents

Obesity remains a serious public health issue in adolescents, who may be subjected to weight stigma leading to increased stress and poor health outcomes. Stigma can be detrimental to adolescents during self-identity formation. The purpose of this study was to examine weight stigma in adolescents in light of the Identity Threat Model of Stigma. A cross-sectional correlational design was used to examine the relationships among the variables of weight stigma, psychosocial stress, coping styles, disordered eating, and physical inactivity. Regression modeling and path analysis were used to analyze the data. Over 90% of the sample had scores indicating weight stigma or antifat bias. Avoidant coping style and psychosocial stress predicted disordered eating. The strongest path in the model was from avoidant coping to disordered eating. The Identity Threat Model of Stigma partially explained adolescents' weight stigma. Nursing practice implications are discussed.

Obesity is associated with lack of inhibitory control and impaired heart rate variability reactivity and recovery in response to food stimuli

Recent theories compare obesity with addiction in terms of lack of inhibitory control in both clinical populations. The present study hypothesized impaired inhibition in obese patients reflected both in executive functions and reduced vagal tone (indexed by a decrease in heart rate variability; HRV) in response to food stimuli. Twenty-four inpatients with obesity (19 women) and 37 controls (24 women) underwent ECG monitoring during baseline, food stimuli viewing, and a recovery phase. Tests and questionnaires assessing inhibitory control and psychopathological dispositions were also administered. As hypothesized, patients were characterized by deficits in all the tests measuring inhibitory capacities. Results also show greater HRV reduction and impaired HRV recovery in response to food stimuli in obese patients compared to controls. The drive to eat experienced by obese patients in the absence of caloric need may rely on impairments in inhibitory and vagal functioning. Results are discussed in terms of implications for therapy.

Sexual Minority Stressors, Internalizing Symptoms, and Unhealthy Eating Behaviors in Sexual Minority Youth

BACKGROUND

Sexual minorities are more likely than heterosexuals to engage in unhealthy eating behaviors.

PURPOSE

The purpose of this study is to examine sexual minority stressors and internalizing symptoms as predictors of unhealthy eating behaviors among sexual minority youths.

METHODS

We used longitudinal data from 1461 sexual minority youths in the Growing Up Today Study, across ages 14-28 years. We hypothesized that sexual minority stressors would predict unhealthy eating behaviors, in part due to internalizing symptoms. Linear regression models fit via generalized estimating equations were stratified by gender and sexual orientation.

RESULTS

Significant positive and inverse associations between stressors and eating behaviors were detected among females and males, with more significant associations among females. Associations were attenuated by up to 71 % for females and 12 % for males when internalizing symptoms were added to the models.

CONCLUSIONS

Sexual minority stressors predicted unhealthy eating behaviors overall and more so for some sexual orientation and gender groups; associations were partially explained by internalizing symptoms. The conceptual model appears to best describe the experiences of bisexual females. Findings have clinical implications for adolescent health.

Stress, cortisol, and obesity: a role for cortisol responsiveness in identifying individuals prone to obesity

There is a strong inter-relationship between activation of the hypothalamo-pituitary-adrenal axis and energy homeostasis. Patients with abdominal obesity have elevated cortisol levels. Furthermore, stress and glucocorticoids act to control both food intake and energy expenditure. In particular, glucocorticoids are known to increase the consumption of foods enriched in fat and sugar. It is well-known that, in all species, the cortisol response to stress or adrenocorticotropin is highly variable. It has now emerged that cortisol responsiveness is an important determinant in the metabolic sequelae to stress. Sheep that are characterized as high-cortisol responders (HRs) have greater propensity to weight gain and obesity than low-cortisol responders (LRs). This difference in susceptibility to become obese is associated with a distinct metabolic, neuroendocrine, and behavioral phenotype. In women and ewes, HR individuals eat more in response to stress than LR. Furthermore, HR sheep have impaired melanocortin signaling and reduced skeletal muscle thermogenesis. High-cortisol responder sheep exhibit reactive coping strategies, whereas LRs exhibit proactive coping strategies. This complex set of traits leads to increased food intake and reduced energy expenditure in HR and thus, predisposition to obesity. We predict that cortisol responsiveness may be used as a marker to identify individuals who are at risk of weight gain and subsequent obesity.

Interactions between sleep, stress, and metabolism: From physiological to pathological conditions

Poor sleep quality due to sleep disorders and sleep loss is highly prevalent in the modern society. Underlying mechanisms show that stress is involved in the relationship between sleep and metabolism through hypothalamic–pituitary–adrenal (HPA) axis activation. Sleep deprivation and sleep disorders are associated with maladaptive changes in the HPA axis, leading to neuroendocrine dysregulation. Excess of glucocorticoids increase glucose and insulin and decrease adiponectin levels. Thus, this review provides overall view of the relationship between sleep, stress, and metabolism from basic physiology to pathological conditions, highlighting effective treatments for metabolic disturbances.

Mice that gorged during dietary restriction increased foraging related behaviors and differed in their macronutrient preference when released from restriction

Caloric restriction (CR) can trigger gorging behavior. We examined macronutrient choice and behavior in mice that gorged during restriction compared to restricted non-gorgers and controls. Fifty MF1 male mice were restricted to 75% of ad-libitum food intake (FI), while ten controls were fed ad-lib. Body mass (BM) and FI were measured two and 24-h after food inclusion over 14-days. ‘Gorging’ mice were defined as those which ate over 25% of their daily FI in 2-h. The top 11 gorgers and the lowest 9 gorgers, along with 10 controls, had their behavior analysed during restriction, and were then provided with an unrestricted food choice, consisting of three diets that were high in fat, protein or carbohydrate. During restriction gorgers ate on average 51% of their daily FI in the 2-h following food introduction while the non-gorgers ate only 16%. Gorgers lost significantly more BM than non-gorgers possibly due to an increased physical activity linked to anticipation of daily food provision. Controls and non-gorgers spent most of their time sleeping. After restriction, both gorgers and non-gorgers were hyperphagic until their lost weight was regained. All 3 groups favoured high fat food. Gorgers and non-gorgers had a significantly greater high carbohydrate diet intake than controls, and gorgers also had a significantly greater high protein diet intake than non-gorgers and controls. On unrestricted food, they did not continue to gorge, although they still had a significantly greater 2-h FI than the other groups. Elevated protein intake may play an important role in the recovery of the lost lean tissue of gorgers after restriction.

The interaction of acute and chronic stress impairs model-based behavioral control

It is suggested that acute stress shifts behavioral control from goal-directed, model-based toward habitual, model-free strategies. Recent findings indicate that interindividual differences in the cortisol stress response influence model-based decision-making. Although not yet investigated in humans, animal studies show that chronic stress also shifts decision-making toward more habitual behavior. Here, we ask whether acute stress and individual vulnerability factors, such as stress reactivity and previous exposure to stressful life events, impact the balance between model-free and model-based control systems. To test this, 39 male participants (21-30 years old) were exposed to a potent psychosocial stressor (Trier Social Stress Test) and a control condition in a within-subjects design before they performed a sequential decision-making task which evaluates the balance between the two systems. Physiological and subjective stress reactivity was assessed before, during, and after acute stress exposure. By means of computational modeling, we demonstrate that interindividual variability in stress reactivity predicts impairments in model-based decision-making. Whereas acute psychosocial stress did not alter model-based behavioral control, we found chronic and acute stress to interact in their detrimental effect on decision-making: subjects with high but not low chronic stress levels as indicated by stressful life events exhibited reduced model-based control in response to acute psychosocial stress. These findings emphasize that stress reactivity and chronic stress play an important role in mediating the relationship between stress and decision-making. Our results might stimulate new insights into the interplay between chronic and acute stress, attenuated model-based control, and the pathogenesis of various psychiatric diseases.

Chronic subordination stress induces hyperphagia and disrupts eating behavior in mice modeling binge-eating-like disorder

Background: Eating disorders are associated with physical morbidity and appear to have causal factors like stressful life events and negative affect. Binge-eating disorder (BED) is characterized by eating in a discrete period of time a larger than normal amount of food, a sense of lack of control over eating, and marked distress. There are still unmet needs for the identification of mechanisms regulating excessive eating, which is in part due to the lack of appropriate animal models. We developed a naturalistic murine model of subordination stress-induced hyperphagia associated with the development of obesity. Here, we tested the hypotheses that the eating responses of subordinate mice recapitulate the BED and that limiting hyperphagia could prevent stress-associated metabolic changes.

Methods: Adult male mice were exposed to a model of chronic subordination stress (CSS) associated with the automated acquisition of food intake and we performed a detailed meal pattern analysis. Additionally, using a pair-feeding protocol we tested the hypothesis that the manifestation of obesity and the metabolic syndrome could be prevented by limiting hyperphagia.

Results: The architecture of feeding of subordinate mice was disrupted during the stress protocol due to disproportionate amount of food ingested at higher rate and with shorter satiety ratio than control mice. Subordinate mice hyperphagia was further exacerbated in response to either hunger or to the acute application of a social defeat. Notably, the obese phenotype but not the fasting hyperglycemia of subordinate mice was abrogated by preventing hyperphagia in a pair-feeding paradigm.

Conclusion: Overall, these results support the validity of our CSS to model BED allowing for the determination of the underlying molecular mechanisms and the generation of testable predictions for innovative therapies, based on the understanding of the regulation and the control of food intake.

Emotion regulation model in binge eating disorder and obesity--a systematic review

Deficits in emotion regulation processes are a common and widely used explanation for the development and maintenance of binge eating disorder (BED). It is assumed that BED patients - as they have difficulty regulating their negative emotions - use binge eating to cope with these emotions and to find relief. However, the number of experimental studies investigating this assumption is scarce and the differentiation of obese individuals with and without BED regarding the emotion regulation model is not verified. We reviewed literature for experimental studies investigating the emotion regulation model in obese patients (OB) with and without BED. Our search resulted in 18 experimental studies examining the triggering effect of negative emotions for binge eating or its effects on subsequent relief. We found evidence indicating that negative emotion serves as a trigger for binge eating in the BED group unlike the obese group without BED. Considering the small number of studies, we found evidence for a (short-term) improvement of mood through food intake, irrespective of group.

Controversies about a common etiology for eating and mood disorders

Obesity and depression represent a growing health concern worldwide. For many years, basic science and medicine have considered obesity as a metabolic illness, while depression was classified a psychiatric disorder. Despite accumulating evidence suggesting that obesity and depression may share commonalities, the causal link between eating and mood disorders remains to be fully understood. This etiology is highly complex, consisting of multiple environmental and genetic risk factors that interact with each other. In this review, we sought to summarize the preclinical and clinical evidence supporting a common etiology for eating and mood disorders, with a particular emphasis on signaling pathways involved in the maintenance of energy balance and mood stability, among which orexigenic and anorexigenic neuropeptides, metabolic factors, stress responsive hormones, cytokines, and neurotrophic factors.

Urinary cortisol and psychopathology in obese binge eating subjects

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Cortisol response and desire to binge following psychological stress: comparison between obese subjects with and without binge eating disorder

While stress and negative affect are known to precede "emotional eating", this relationship is not fully understood. The objective of this study was to explore the relationship between induced psychological stress, hypothalamic-pituitary-adrenal (HPA) axis activity, and eating behavior in binge eating disorder (BED). The Trier Social Stress Test (TSST) was applied in obese participants with (n=8) and without BED (n=8), and normal weight controls (n=8). Psychological characteristics, eating-related symptoms, and cortisol secretion were assessed. Baseline stress, anxiety and cortisol measures were similar in all groups. At baseline desire to binge was significantly higher among the BED group. While the TSST induced an increase in cortisol levels, a blunted cortisol response was observed in the BED group. In the BED group, a positive correlation was found between cortisol (area under the curve) levels during the TSST and the change in VAS scores for desire to binge. Post-TSST desire to binge and sweet craving were significantly higher in the BED group and correlated positively with stress, anxiety, and cortisol response in the BED group only. These results suggest chronic down-regulation of the HPA axis in participants with BED, and a relationship between psychological stress, the acute activation of the HPA axis, and food craving.

The Role of Anxiety in Binge Eating Behavior: A Critical Examination of Theory and Empirical Literature

The purpose of this manuscript is to expand the understanding of binge eating by reviewing the role of aspects of negative affect. Specifically, this paper will present evidence for further investigation of the bearing that anxiety may have in binge eating development and maintenance. A comprehensive review of the literature regarding the relation of binge eating and anxiety was performed. Valuable contributions have been made to the binge eating literature regarding some aspects of negative affect (i.e., depression); however, outside of bulimia nervosa studies, much of the theoretical and empirical binge eating research to date has not directly addressed the role of anxiety. Research supports expansion of investigations of negative emotionality and binge eating to include specific study of anxiety. Greater inclusivity and specificity in the unique contributions of various negative emotions may further the development of temporal models and intervention efforts.