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

Experience with multiple devaluation is associated with elevated emotional eating, perceived weight, and body mass index: An exploration of mediating factors and the role of irrational beliefs in general population and university samples

Weight stigma, the social devaluation of people based on a perception of high body weight, is associated with a number of adverse health consequences including avoidance of medical care, suicide risk, disordered eating, decreased exercise, and weight gain. Experiences of stigma in a variety of domains in addition to weight may intersect to exacerbate these outcomes. Participants in two samples (one of 327 women and men from the general population and one of 128 female university students) reported experiences of devaluation on three body size and eight non-body size-related characteristics (referred to as multiple devaluation experience or MDE) and completed assessments of emotional eating (EE), feeling fat, weight self-stigma, impulsivity, and irrational beliefs. Participants were also asked to rate their body weight. MDE was correlated with elevated weight self-devaluation and anticipation of weight stigma, negative EE (NEE), feeling fat, and impulsivity in both men and women. None of these measures moderated the relationship between MDE and EE. The positive relationship between MDE and NEE was mediated by anticipated weight stigma only in women in the general population sample at higher levels of irrational beliefs. The positive relationship between MDE and body mass index (BMI) was mediated by NEE in women in the general population. The positive relationship between MDE and perceived body weight was mediated by feeling fat in women in both samples. These results suggest that women's experiences of stigma may increase anticipation of ongoing stigma, prompting NEE and resulting in elevated BMI. The results also suggest that feelings of fatness could lead to an elevation of women's perceived body weight, which in prospective studies is linked to later elevation of actual weight.

Chrononutrition behaviors and cardiometabolic risk in adolescence: an ecological momentary assessment study

PURPOSE

To investigate the potential associations between unhealthy chrononutrition behaviors (meal timing, frequency, and regularity) and their combined impact on cardiometabolic risk in adolescence.

METHODS

Chrononutrition behaviors were assessed using a 7-day ecological momentary assessment (EMA). The unhealthy chrononutrition score (ranging from 0 to 8) was determined based on late meal timing, low meal frequency, and meal irregularity. The cardiometabolic (CM)-risk z score was calculated utilizing age- and sex-specific reference values for waist circumference (WC), mean arterial pressure (MAP), homeostatic model assessment of insulin resistance (HOMA-IR), triglycerides (TG), and high-density lipoprotein cholesterol (HDL-C). Restricted cubic splines were employed to estimate the dose-response relationships between the unhealthy chrononutrition score and outcomes.

RESULTS

Among 458 participants [mean (SD) age, 17.9 (0.7) years; 340 (74.2%) Female], 14.3% had an unhealthy chrononutrition score ≥ 6, who exhibited higher MAP (β = 3.86; 95% CI 1.24, 6.47), higher CM-risk scores (β = 1.80; 95% CI 0.70, 2.90), and lower HDL-C (β = 0.18; 95% CI - 0.30, - 0.06), as opposed to those with a healthy score ≤ 2 (n = 136, 31.4%). Moreover, late breakfast (later than 9AM compared to earlier than 8AM), low meal frequency (eating two or fewer meals versus three meals a day), and meal irregularity (score of 3-5 compared to a good score of 6-9) were associated with an increased risk of CM-risk outcomes.

CONCLUSION

The findings suggest a clustering of unhealthy chrononutrition behaviors that collectively impact cardiometabolic health in adolescence. Further prospective and interventional investigations is necessary to validate these findings and explore the underlying mechanisms.

Stress-induced eating in rural adolescents: Unique variability among boys and adolescents with obesity

Stress may contribute to the development of obesity through its effects on dysregulated eating, although this has not yet been examined among low-income, rural adolescents. We examined adolescents' stress-induced changes in eating an ad libitum meal, and after, in the absence of hunger (EAH), and the extent to which these varied by sex, race, and weight status. Participants included 260 adolescents, drawn from a sample of rural households experiencing poverty. Adolescents completed two home visits while salivary cortisol was measured; during the control (low stress) visit, they completed questionnaires and procedures thought to elicit low levels of stress and had BMI assessed. During the stress visit, adolescents completed a 20-min set of psychosocial stress challenges before eating. At each visit, adolescents consumed an ad-libitum meal after which they were additionally given large portions of snacks (EAH task). Results revealed that indeed cortisol was higher during the stress visit, across the sample. Boys showed stress-induced increases during ad-libitum meal intake (for calories, fat, and carbohydrates) whereas girls exhibited decreased intake. Further, adolescents with obesity showed stress-induced increases in fat intake, but only when hunger was satiated (EAH). There were no differences by race. These findings provide the first evidence of stress-induced alterations in food intake in a rural, low-income sample of adolescents and point to a strong vulnerability for stress-induced increases in eating in rural boys as well as stress-induced increases in fat intake when satiated as a possible contributor to obesity in youth.

Sex-related differences in eating behaviors during COVID-19 pandemic: A systematic review with metanalysis

Eating behavior can be influenced by external factors; however, there is no consensus on the existence of differences in eating behavior between the sexes in stressful situations, such as the COVID-19 pandemic. This systematic review assessed whether there was a difference in eating behavior between sexes during the COVID-19 pandemic. A search of nine databases (Medline/Pubmed, Embase, Scielo, VHL, Scopus, PsycINFO, Web of Science, ProQuest, Google Scholar) was conducted in October 2023. Studies reporting eating behaviors in males and females during the COVID-19 pandemic were included. Methodological quality was assessed using the Joanna Briggs Institute Critical Appraisal Instrument. Stratified meta-analyses were conducted using the STATA software. Of the 2388 studies identified, 45 were included in the qualitative synthesis, and 36 in the meta-analysis, encompassing a total of 35,792 participants. Validated questionnaires were used to assess eating behavior, including the TFEQ (33.3%), DEBQ (24.4%), EEQ (22.2%), EES (11.1%), EOQ-5 (2.2%), AEBQ (2.2%), EAS (2.2%), and EMAQ (2.2%). Overall, males exhibited lower scores in emotional eating (Cohen's d = -0.32, 95%CI: 0.46 to -0.17) and restrained eating (Hedges'g = -0.11, 95%CI: 0.16 to -0.06) compared to females. However, the subgroup analysis indicated no differences in emotional eating (subgroup difference p = 0.39) or restrained eating (subgroup difference p = 0.30) according to the year of pandemic. These findings underscore the importance of sex-specific interventions, the address eating behaviors during periods of heightened insecurity in worldwide health emergencies, such as the COVID-19 pandemic. Additionally, our results emphasize the necessity for public health strategies to monitor and promote healthy eating behaviors to mitigate their impact on overall health outcomes, even in males, as their eating behavior may be affected over the course of a global health crisis, as well as females.

Intermittent access to sugary drinks associated with fasting induces overeating and depressive-like behavior in female C57BL/6J mice

Binge eating disorder is the most prevalent eating disorder, affecting both sexes but more commonly found in women. Given the frequent co-occurrence of psychiatric disorders, this study aimed to establish a standardized experimental intermittent protocol to investigate overeating associated with depression. A 10-day protocol induced uncontrolled eating behavior in C57BL/6J female mice. The first experiment included the following groups: naive group (chow ad libitum), control group (chow and sucrose solution ad libitum), and fasting groups (16 and 20 h) exposed to an intermittent sucrose solution (10 %) and chow regimen. Subsequently, the feeding test, open field test, elevated plus maze test, tail suspension test, and light/dark conflict test were conducted. Furthermore, monoamine oxidase (MAO) A and B activities in brain structures and plasma corticosterone levels were assessed. Food overconsumption and depressive-like behavior were observed in both sucrose fasting groups, while risk-taking behaviors were specifically observed in the 20-hour fasting sucrose group. While both fasting sucrose groups caused reduced hippocampal MAO-A activity, only the F20 sucrose group inhibited MAO-B in the cortex and hypothalamus. Moreover, both fasting sucrose groups exhibited elevated corticosterone levels. In a separate design (Experiment 2), groups with 16 and 20 h of fasting alone (without sucrose) did not show the same behavioral results as the intermittent fasting sucrose groups, thus avoiding fasting bias. Based on these results, the 20-hour sucrose fasting group was chosen as the ideal protocol for mimicking overeating behavior associated with depression to investigate future therapeutic approaches for this comorbidity.

Tackling diet inequalities in the UK food system: is food insecurity driving the obesity epidemic? (The FIO Food project)

By 2050 the number of adults living with obesity in the UK will rise with approximately one in four in the adult population. This rising trend is not equitable, with higher prevalence in socially disadvantaged groups. There is an apparent paradox of not being able to provide food for the family to eat, a feature of food insecurity and living with obesity. With the current cost-of-living crisis, there is a challenge to afford both food and fuel bills. Environmentally sustainable and healthy diets are proposed to improve public health and reduce the impact of the food system on the environment, while also improving diet quality. However, healthier foods tend to be nearly three times more expensive than unhealthy foods, and this provides a challenge for citizens on low incomes. In this review, we explore some of the evidence for solutions in the retail food environment to support the UK food system to be safe, nutritious, environmentally friendly and fair for all. We highlight the value of co-production in research, to give value and power to the lived experience to address these inequalities. Our multidisciplinary research approach within the FIO Food research grant will generate new insights into modifiable and potentially impactful changes to the UK food system, specifically for the retail food sector. We believe that the co-creation, design and delivery of research with those living with obesity and food insecurity will help to transform the UK food system for health and the environment in this vulnerable group.

The Role of Psychosocial Stress on Cardiovascular Disease in Women: JACC State-of-the-Art Review

Psychosocial stress can affect cardiovascular health through multiple pathways. Certain stressors, such as socioeconomic disadvantage, childhood adversity, intimate partner violence, and caregiving stress, are especially common among women. The consequences of stress begin at a young age and persist throughout the life course. This is especially true for women, among whom the burden of negative psychosocial experiences tends to be larger in young age and midlife. Menarche, pregnancy, and menopause can further exacerbate stress in vulnerable women. Not only is psychosocial adversity prevalent in women, but it could have more pronounced consequences for cardiovascular risk among women than among men. These differential effects could reside in sex differences in responses to stress, combined with women's propensity toward vasomotor reactivity, microvascular dysfunction, and inflammation. The bulk of evidence suggests that targeting stress could be an important strategy for cardiovascular risk reduction in women.

Psychometric evaluation of three-factor eating questionnaire -R18 in aging Finnish men with increased risk for type 2 diabetes

BACKGROUND

Deeper comprehension of eating-related behaviour (how and why people eat) can reveal new aspects to support health and prevent type 2 diabetes (T2D). However, such research is largely missing in aging men.

AIM

The aim was to investigate suitability of the Three-Factor Eating Questionnaire-R18 (TFEQ-R18) in Finnish aging men which is widely used to examine factors: cognitive restraint (CR), uncontrolled eating (UE), and emotional eating (EE).

METHODS

Study population consisted of 420 men aged 50-75, who completed the TFEQ-R18 at the baseline of the T2D-GENE lifestyle intervention study. Inclusion criteria were impaired fasting glucose (IFG) and body mass index ≥25 kg/m2. Confirmatory factor analysis was used to study psychometrics (reliability, validity, and model fit) and factor structure of TFEQ-R18.

RESULTS

The items loaded to the three factors (CR, UE, EE) as in previous studies, except two items at CR factor and one at UE factor, which were therefore omitted. UE was also discovered split into two sub factors (named as 'craving' and 'loss-of-control'), UE being a higher-order (h) factor. The resultant revised version was named as Three-Factor Eating Questionnaire Revised to 15-items with higher-order factor (TFEQ-R15h).

CONCLUSION

The original 18-item version of the TFEQ was not optimal in the population consisting of Finnish aging men with elevated T2D risk. A modified 15-item version of the TFEQ could be used to describe EB in this population instead.

Obesity: a gender-view

PURPOSE

There is a growing awareness of the importance of understanding gender differences in obesity. The aim of this short review was to revise the current evidence on anthropometric characteristics and nutritional and pharmacological aspects of obesity from a gender perspective.

METHODS

A literature search within PubMed was performed. Selected publications related to obesity and gender differences were reviewed.

RESULTS

The prevalence of obesity among men is higher than in women, but women have a higher percentage of body fat content compared to men, and gender appears to be an important factor in the manifestation of central (android) or peripheral (gynoid) obesity. In addition, while in most clinical trials, women are still underrepresented, in clinical registration trials of anti-obesity drugs, women are commonly up-represented and gender-specific analysis is uncommon. Considering that adipose tissue is one of the factors affecting the volume of distribution of many drugs, mainly lipophilic drugs, gender differences might be expected in the pharmacokinetics and pharmacodynamics of anti-obesity drugs. Indeed, although Liraglutide 3 mg, a long-acting glucagon-like peptide-1 receptor agonist, and naltrexone/bupropion display lipophilic properties, currently, a gender-dose adjustment for both these drugs administration is not recommended. In addition, despite that predicted responders to treatment offer substantial opportunities for efficient use, especially of expensive new therapies, such as anti-obesity drugs, data on gender differences to identify early responders to both these have not yet been investigated. Finally, bariatric surgery gender disparity reflects healthcare practices. Weight loss similar, but differing effects: women need more correction and face psychology challenges; men have worse physiology and fewer comorbidity improvements.

CONCLUSION

Gender differences exist in obesity prevalence and phenotype, body fat distribution, drug efficacy, clinical trial representation, and different secondary effects of bariatric surgery. Gender is an important variable in obesity analysis.

Sex differences in cortisol levels in depression: A systematic review and meta-analysis

Higher prevalence of depression in females might be associated with sex-specific cortisol levels. Evidence exists that cortisol levels differ between healthy females and males, however a sex-specific association in depression has not been systematically assessed. Thus, the current study quantifies the existing literature on different cortisol parameters, i.e., basal cortisol, hair cortisol, cortisol awakening response (CAR), and cortisol stress reactivity comparing depressed females and males as well as sex-specific comparisons with healthy controls. Following an extensive literature research, fifty original articles were included. Depressed females had significantly higher hair cortisol, higher CAR, and lower cortisol stress reactivity compared to depressed males. In comparison with sex-matched controls, female patients had significantly higher evening basal cortisol, higher CAR and lower cortisol stress reactivity, and male patients had significantly higher general, morning and evening basal cortisol. Overall, sex as a fundamental driver of cortisol levels in depression needs to be taken into account.

A paraventricular thalamus to insular cortex glutamatergic projection gates "emotional" stress-induced binge eating in females

It is well-established that stress and negative affect trigger eating disorder symptoms and that the brains of men and women respond to stress in different ways. Indeed, women suffer disproportionately from emotional or stress-related eating, as well as associated eating disorders such as binge eating disorder. Nevertheless, our understanding of the precise neural circuits driving this maladaptive eating behavior, particularly in women, remains limited. We recently established a clinically relevant model of 'emotional' stress-induced binge eating whereby only female mice display binge eating in response to an acute "emotional" stressor. Here, we combined neuroanatomic, transgenic, immunohistochemical and pathway-specific chemogenetic approaches to investigate whole brain functional architecture associated with stress-induced binge eating in females, focusing on the role of Vglut2 projections from the paraventricular thalamus (PVTVglut2+) to the medial insular cortex in this behavior. Whole brain activation mapping and hierarchical clustering of Euclidean distances revealed distinct patterns of coactivation unique to stress-induced binge eating. At a pathway-specific level, PVTVglut2+ cells projecting to the medial insular cortex were specifically activated in response to stress-induced binge eating. Subsequent chemogenetic inhibition of this pathway suppressed stress-induced binge eating. We have identified a distinct PVTVglut2+ to insular cortex projection as a key driver of "emotional" stress-induced binge eating in female mice, highlighting a novel circuit underpinning this sex-specific behavior.

The role of interoception in age-related obesity: A structural equation modelling study

The obesity pandemic and its adverse effect on health and quality of life are well established. In younger populations, interoception and aberrant eating behaviour contribute to overconsumption and being overweight. Although the incidence of obesity is higher in older individuals, they remain under-researched in the obesity literature. Therefore, the present study considered the role of general (interoceptive sensibility) and appetite-specific (hunger drive and satiety responsiveness) interoception and obesogenic eating behaviour (food responsivity, emotional eating, enjoyment of eating) in the association between age and BMI. A total of 1006 female adults (aged 18 to 80) completed the Adult Eating Behaviour Questionnaire and the Interoceptive Attention and Accuracy scales. Structural Equation Modelling (SEM) in AMOS was used to explore the data for multiple serial mediation effects. Despite being more overweight, older adults reported lower interoceptive attention, hunger drive, emotional overeating, food responsivity, and enjoyment of food. In contrast, compared to younger adults, older adults reported a higher interoceptive accuracy, and a similar responsivity to satiety. Importantly, two indirect pathways positively mediated the link between age and BMI: (1) age ➤(-)➤ interoceptive attention ➤(+)➤ satiety responsivity ➤(-)➤ emotional eating ➤(+)➤ BMI and (2) age ➤(-)➤ interoceptive attention ➤(+)➤ satiety responsivity ➤(-)➤ food responsivity ➤(+)➤ BMI. However, a stronger antagonistic indirect pathway was also present: age ➤(-)➤ interoceptive attention ➤(+)➤ hunger drive ➤(+)➤ emotional eating ➤(+)➤ BMI. The present findings suggested that overall reduced interoceptive attention in older adults may protect against weight gain by lowering hunger and the propensity towards obesogenic eating behaviours. These findings have implications for the design of appetite interventions in older populations.

Sex-specific association between regional gray matter volume and spicy food craving or consumption

Both food cravings and long-term food consumption have been associated with brain changes. Sex differences in food craving are robust and substantial. The current study examined the potential sex-specific neuroanatomical correlates of spicy food craving and habitual spicy food consumption. One hundred and forty-nine participants completed the Spicy Food Consumption Questionnaire and the Spicy Food Craving Questionnaire while their structural brain images were acquired using a 3-T scanner. Multiple regression analysis was used to examine regional gray matter volume (GMV) in relation to questionnaire scores. GMV of the right supplementary motor area (SMA) and the dorsal superior frontal gyrus were significantly correlated with spicy food craving in women, whereas spicy food craving was associated with greater GMV of the inferior temporal gyrus and the occipital gyrus in men. In addition, habitual spicy food consumption was correlated with increased GMV of the bilateral putamen, left postcentral gyrus, and right paracentral lobule, which was more pronounced among female participants. These findings suggest distinct central neuroanatomical reflections of trait craving or habitual exposure to spicy flavors. The sex-specific correlation between spicy food craving and brain anatomical features may be related to food-related sensory imagery or cognitive control.

The mGlu2/3 agonist LY379268 reduces sucrose taking, seeking, and motivation in male and female rats

OBJECTIVES

The mGlu2/3 receptor agonist LY379268 reduces sucrose-seeking, but not sucrose-taking, in male rats. This study explored the generality of this effect across the sexes. In addition, the effect of the drug on motivation to receive sucrose was assessed.

METHODS

Adult male and female Long-Evans rats ( N  = 91) were challenged with LY379268 in three experiments: (1) a fixed ratio (FR) schedule of reinforcement (taking), (2) extinction of responding previously reinforced on the FR (seeking) or (3) responding reinforced on a progressive ratio (PR) schedule of reinforcement (motivation). For each experiment, rats first responded to 10% liquid sucrose on an FR in 10 daily 2-h sessions. For the PR study, this was followed by training on a PR for 7 daily 3-h sessions. Rats were then challenged in a counterbalanced order with LY379268 (0, 1.5, 3 and 6 mg/kg; IP; 30-min pretreatment) on test days, followed by either three reacquisition days of FR (experiments 1 and 2) or PR (experiment 3) responding.

RESULTS

Female rats responded more to sucrose on the FR and PR. LY379268 reduced responding in all three experiments. LY379268 challenge to sucrose taking on the FR produced an inverted U-shaped function while extinction responding and responding for sucrose on the PR were decreased dose-dependently, with PR responding insensitive to the 1.5 mg/kg dose. There were no sex-dependent effects of the drug on sucrose-directed responding.

CONCLUSIONS

The sucrose anti-taking, -seeking, and -motivation effects of LY379268 across male and female rats support further evaluation of glutamate modulation as an antiaddiction pharmacotherapy.

Fast neurotransmitter identity of MCH neurons: Do contents depend on context?

Hypothalamic melanin-concentrating hormone (MCH) neurons participate in many fundamental neuroendocrine processes. While some of their effects can be attributed to MCH itself, others appear to depend on co-released neurotransmitters. Historically, the subject of fast neurotransmitter co-release from MCH neurons has been contentious, with data to support MCH neurons releasing GABA, glutamate, both, and neither. Rather than assuming a position in that debate, this review considers the evidence for all sides and presents an alternative explanation: neurochemical identity, including classical neurotransmitter content, is subject to change. With an emphasis on the variability of experimental details, we posit that MCH neurons may release GABA and/or glutamate at different points according to environmental and contextual factors. Through the lens of the MCH system, we offer evidence that the field of neuroendocrinology would benefit from a more nuanced and dynamic interpretation of neurotransmitter identity.

Low eating self-efficacy is associated with unfavorable eating behavior tendencies among individuals with overweight and obesity

Success in long-term weight management depends partly on psychological and behavioral aspects. Understanding the links between psychological factors and eating behavior tendencies is needed to develop more effective weight management methods. This population-based cross-sectional study examined whether eating self-efficacy (ESE) is associated with cognitive restraint (CR), uncontrolled eating (UE), emotional eating (EE), and binge eating (BE). The hypothesis was that individuals with low ESE have more unfavorable eating behavior tendencies than individuals with high ESE. Participants were classified as low ESE and high ESE by the Weight-Related Self-Efficacy questionnaire (WEL) median cut-off point. Eating behavior tendencies were assessed with Three Factor Eating Questionnaire R-18 and Binge Eating Scale, and additionally, by the number of difficulties in weight management. The difficulties were low CR, high UE, high EE, and moderate or severe BE. Five hundred and thirty-two volunteers with overweight and obesity were included in the study. Participants with low ESE had lower CR (p < 0.03) and higher UE, EE, and BE (p < 0.001) than participants with high ESE. Thirty-nine percent of men with low ESE had at least two difficulties in successful weight control while this percentage was only 8% in men with high ESE. In women, the corresponding figures were 56% and 10%. The risk of low ESE was increased by high UE [OR 5.37 (95% CI 1.99-14.51)], high EE [OR 6.05 (95% CI 2.07-17.66)], or moderate or severe BE [OR 12.31 (95% CI 1.52-99.84)] in men, and by low CR [OR 5.19 (95% CI 2.22-12.18)], high UE [OR 7.20 (95% CI 2.41-19.22)], or high EE [OR 23.66 (95% CI 4.79-116.77)] in women. Low ESE was associated with unfavorable eating behavior tendencies and multiple concomitant difficulties in successful weight loss promotion. These eating behavior tendencies should be considered when counseling patients with overweight and obesity.

Neural correlates of Type A personality: Type A personality mediates the association of resting-state brain activity and connectivity with eating disorder symptoms

BACKGROUND

Type A personality (TAP) was characterized by impatience, competitiveness, aggressiveness, and hostility. Higher TAP was proved to be associated with more eating disorder symptoms (EDS). While little is known about the underlying neural substrates of TAP and how TAP is linked to EDS at the neural level.

METHODS

To investigate the neural basis of TAP, we adopted fractional amplitude of low-frequency fluctuations (fALFF) and resting-state functional connectivity (RSFC) via resting-state functional magnetic resonance imaging (rs-fMRI) (N = 1620). Mediation models were examined to explore the relationship between TAP, EDS, and brain activity.

RESULTS

TAP was associated with decreased fALFF in the left middle frontal gyrus (MFG) and increased fALFF in the left precentral gyrus (PreCG). Furthermore, TAP was positively correlated to RSFC between the left MFG and left inferior temporal gyrus (ITG) and between the left PreCG and right middle temporal gyrus (MTG). Mediation analysis showed TAP fully mediated the association of the left MFG activity, MFG-ITG connectivity, and PreCG-MTG connectivity with EDS.

LIMITATIONS

The cross-sectional design of this study precludes us from specifying the causal relationship in the associations we observed.

CONCLUSIONS

Our results suggested spontaneous activity in the left MFG and PreCG is associated with TAP, and even in general sample, people with higher TAP showed more EDS. The present study is the first to investigate the neurobiological underpinnings of TAP in a large sample and further offered new insights into the relation between TAP and EDS from a neural basis perspective.

Binge eating, overeating and food addiction: Approaches for examining food overconsumption in laboratory rodents

Overeating ranges in severity from casual overindulgence to an overwhelming drive to consume certain foods. At its most extreme, overeating can manifest as clinical diagnoses such as binge eating disorder or bulimia nervosa, yet subclinical forms of overeating such as emotional eating or uncontrolled eating can still have a profoundly negative impact on health and wellbeing. Although rodent models cannot possibly capture the full spectrum of disordered overeating, studies in laboratory rodents have substantially progressed our understanding of the neurobiology of overconsumption. These experimental approaches range from simple food-exposure protocols that promote binge-like eating and the development of obesity, to more complex operant procedures designed to examine distinct 'addiction-like' endophenotypes for food. This review provides an overview of these experimental approaches, with the view to providing a comprehensive resource for preclinical investigators seeking to utilize behavioural models for studying the neural systems involved in food overconsumption.

Emotional Regulation Underlies Gender Differences in Pathological Eating Behavior Styles of Bariatric Surgery Candidates

Almost a third of bariatric surgery patients present suboptimal weight loss or important weight regain in the first five postoperative years. While the reasons underlying this are not fully understood, it is known that pathological eating styles (such as emotional or binge eating) can thwart efforts to maintain weight loss. However, detailed characterization and understanding of these eating styles have yet to be achieved. In particular, research on gender differences in pathological eating styles and psychiatric symptoms before bariatric surgery is lacking. To characterize gender differences in eating styles and their association with clinical symptoms, we prospectively enrolled 110 bariatric surgery candidates, collecting eating styles and clinical scores. Women displayed a higher frequency of emotional eating as compared to men (x2 = 9.07, p = 0.003), while men showed a higher frequency of quantitative eating behavioral style (x2 = 4.58, p = 0.044). Binge eating style was associated with higher Difficulties in Emotion Regulation Scale (DERS), Hamilton Depression Scale (HAM-D), and Hamilton Anxiety Scale (HAM-A) scores (p < 0.05). Emotional eating style was associated with higher HAM-D and HAM-A scores (p < 0.05). The present findings highlight the importance of understanding the role of gender differences in emotion regulation processes involved in the development and maintenance of pathological eating styles in bariatric surgery candidates. This paves the way to gender- and symptoms-specific interventions on eating behaviors to improve surgery long-term outcomes.

Childhood and adolescent nutrition outcomes among girls exposed to gender-based violence: A rapid evidence assessment of quantitative research

BACKGROUND

An emerging evidence base has explored the nutritional consequences of gender-based violence (GBV) perpetrated against girls during childhood/adolescence. We conducted a rapid evidence assessment of quantitative studies describing associations between GBV and girls' nutrition.

METHODS

We adapted systematic review methods and included empirical, peer-reviewed studies, published after 2000 (until November, 2022), that were written in Spanish or English and reported quantitative associations between girls' exposure to GBV and nutrition outcomes. A variety of GBV forms were considered: childhood sexual abuse (CSA), child marriage, preferential feeding of boys, sexual IPV and dating violence. Nutrition outcomes included anemia, underweight, overweight, stunting, micronutrient deficiencies, meal frequency, and dietary diversity.

RESULTS

In total, 18 studies were included, 13 of which were conducted in high-income countries. Most sources utilized longitudinal or cross-sectional data to quantify associations between CSA, sexual assault, and intimate partner/dating violence and elevated BMI/overweight/obesity/adiposity. Findings suggest that CSA perpetrated by parents/caregivers is associated with elevated BMI/overweight/obesity/adiposity via cortisol reactivity and depression; this relationship may be compounded by additional intimate partner/dating violence in adolescence. The effects of sexual violence on BMI are likely to emerge during a sensitive period of development between late adolescence and young adulthood. Emerging evidence was found regarding the relationship between child marriage (and the related exposure: age at first pregnancy) and undernutrition. The association between sexual abuse and reduced height and leg length was inconclusive.

CONCLUSION

Given that only 18 studies were included, the relationship between girls' direct exposure to GBV and malnutrition has received little empirical attention, especially with respect to studies conducted in LMIC and fragile settings. Most studies focused on CSA and overweight/obesity, where significant associations were found. Future research should test the moderation and mediation effects of intermediary variables (depression, PTSD, cortisol reactivity, impulsivity, emotional eating) and consider sensitive periods of development. Research should also explore the nutritional consequences of child marriage.

Sex Differences in Effects of Mood, Eating-Related Behaviors, and BMI on Food Appeal and Desire to Eat: A Cross-Sectional Survey Study

Although sex differences in food intake have been observed consistently, contributing factors are not well understood. Using a cross-sectional online survey (n = 306; 151 men, 155 women), this study aimed to assess how sex impacts relationships between food ratings (appeal/desire to eat for high-calorie (HC) and low-calorie (LC) food images) and eating-related attitudes/behaviors, body mass index (BMI), and mood. Across participants, increased state- and trait-based hunger, disinhibition, and cravings were associated with both increased HC appeal and desire (p < 0.001). Increased state-based hunger and cravings were associated with greater LC desire (p < 0.001). Greater satiety was associated with decreased desire for both HC and LC (p < 0.001), while greater anxiety was associated with increased desire for both HC and LC (p < 0.001). Significant associations between BMI and food ratings were not observed. Women reported greater dietary restraint, trait-based hunger, disinhibition, eating disorder-related behaviors, depression, and stress compared to men, in addition to greater appeal and familiarity with LC foods (all p < 0.05). Significant effects of sex on the associations between food ratings and eating-related attitudes/behaviors, BMI, and mood were not observed, however. Findings support the importance of considering mood and eating-related attitudes/behaviors in investigations of food cue responsivity.

A Comparison of Emotional Triggers for Eating in Men and Women with Obesity

OBJECTIVE

Emotional eating (EE) is prevalent in people seeking obesity treatment and is a contributor to poor weight loss outcomes. We aimed to delineate the emotions most associated with this type of eating, and whether they differ by sex in people undergoing obesity treatment.

METHODS

A cross-sectional study recruiting 387 adults from a hospital obesity management service. Emotional eating was measured using the Emotional Eating Scale (EES). Separate analyses included all participants, and those undergoing lifestyle interventions alone or in combination with obesity medication and/or bariatric surgery.

RESULTS

A total of 387 people (71% women) participated in the study (n = 187 receiving lifestyle modification alone; n = 200 in combination with additional treatments). Feeling 'bored' was most commonly and most strongly associated with the urge to eat, regardless of sex or treatment. Women had higher scores for total EES, for subscales of depression and anger, and individual feelings of 'blue', 'sad' and 'upset' compared to men.

CONCLUSIONS

Understanding why certain emotions differentially trigger an urge to eat in men and women, and finding strategies to break the link between boredom and eating may enable better personalisation of lifestyle interventions for people with obesity.

Compulsive-like eating of high-fat high-sugar food is associated with 'addiction-like' glutamatergic dysfunction in obesity prone rats

Chronic overeating is a core feature of diet-induced obesity. There is increasing evidence that in vulnerable individuals, such overeating could become compulsive, resembling an addictive disorder. The transition to compulsive substance use has been linked with changes at glutamatergic synapses in the nucleus accumbens. In this study, we investigated a potential link between such glutamatergic dysregulation and compulsive-like eating using a rat model of diet-induced obesity. A conditioned suppression task demonstrated that diet-induced obese rats display eating despite negative consequences, as their consumption was insensitive to an aversive cue. Moreover, nucleus accumbens expression of GluA1 and xCT proteins was upregulated in diet-induced obese animals. Lastly, both a computed 'addiction score' (based on performance across three criteria) and weight gain were positively correlated with changes in GluA1 and xCT expression in the nucleus accumbens. These data demonstrate that the propensity for diet-induced obesity is associated with compulsive-like eating of highly palatable food and is accompanied by 'addiction-like' glutamatergic dysregulation in the nucleus accumbens, thus providing neurobiological evidence of addiction-like pathology in this model of obesity.

Brain serotonin deficiency and fluoxetine lead to sex-specific effects on binge-like food consumption in mice

RATIONALE

Although pharmacotherapies are often effective in reducing binge eating in conditions such as bulimia nervosa and binge eating disorder, subsets of patients do not benefit sufficiently from existing treatments, and the reasons for treatment failure remain unclear.

OBJECTIVES

This study aimed to evaluate whether genetic reductions in brain serotonin influence binge eating and/or the ability of fluoxetine, a selective serotonin reuptake inhibitor, to reduce binge eating in mice.

METHODS

This study used a validated model of binge-like consumption of high-fat diet to compare binge-like food intake in control and fluoxetine-treated wild-type and serotonin-deficient mice from the tryptophan hydroxylase 2 (R439H) knock-in line. In addition, real-time PCR was used to evaluate potential genotype and sex differences in the effects of fluoxetine on gene expression in the raphe nucleus.

RESULTS

The results reveal that brain serotonin deficiency is sufficient to increase binge eating in males, but not females. However, while chronic fluoxetine reduced binge eating in both genotypes of males and in wild-type females, it failed to reduce binge eating in serotonin-deficient females. Transcriptional responses to chronic fluoxetine were also characterized by sex and genotype differences.

CONCLUSIONS

Overall, this study revealed significant sex differences in the effects of fluoxetine and brain serotonin deficiency on binge-like food intake and suggests that low brain serotonin could impact eating disorders both by promoting binge eating and by limiting the efficacy of fluoxetine to reduce binge eating.

Exploring the Associated Factors of Depression, Anxiety, and Stress among Healthcare Shift Workers during the COVID-19 Pandemic

Background: The recent pandemic of COVID-19 has had a tremendous impact on healthcare frontliners. This study sought to assess healthcare shift workers’ depression, anxiety, and stress and its associated factors. Methods: The sampling frame includes healthcare shift workers directly managing COVID-19 cases around Klang Valley, Malaysia. The participants’ mental health status was assessed using the Depression, Anxiety, Stress Scale-21 (DASS-21). The associated factors specified in this study include sleep quality, physical activities, and eating habits. Pearson’s χ2 and simple and multivariable binary logistic regression models were constructed following the Hosmer–Lemeshow approach to determine the potential associated factors. Results: A total of 413 participants were recruited. Overall, 40.7% of participants had one or more symptoms of depression, anxiety, or stress. Poor sleep quality was significantly associated with all mental health outcomes of depression, anxiety, and stress. Inactivity was found to be strongly associated with symptoms of depression and anxiety. At the same time, eating habits were strongly associated with anxiety and stress. Conclusions: Sleep quality, inactivity, and eating habits that were found to be associated with the mental health status of healthcare shift workers are modifiable factors that must be addressed to curb mental health issues among this group of workers.

Weight Cycling and Dieting Behavior in Fitness Club Members

Background

Along with the rising prevalence of high body-mass index (BMI), there is also increased emphasis on leanness and fitness. Both these trends suggest that many individuals are concerned about weight management and may try to lose weight. Using data from the research project "Fitness clubs - a venue for public health?", we aimed to describe weight cycling and energy-restricted dieting in men and women at start-up of fitness club membership, and to investigate influencing factors [age, BMI, educational level, self-classified overweight/obesity, compliance with nutritional guidelines, unhealthy weight control strategies and self-perceived health (SPH)].

Methods

In a cross-sectional online survey, 250 men and women from 25 fitness clubs in Oslo, reported anthropometrics, self-classified weight group, weight cycling, weight loss/gain, eating habits/dieting, and background/health information. Enrollment was limited to adult (≥18 years) novice exercisers (exercising <60 min/week at a moderate or vigorous intensity or brisk walking <150 min/week, the past six months) with less than four weeks of membership. Factors associated with weight cycling were examined using simple and multiple logistic regression, separated for men and women.

Results

In both sexes (mean age: 36.4 ± 11.3, range 18-71 years), a high number reported substantial weight fluctuation (+/-5 kg) the past 12 months (men: 50% and women: 62%, mean difference 12%, 95% CI -0.3 to 23.8, p=0.056) and unhealthy weight control strategies (men: 24.8% and women: 47.2%, mean difference 22.4%, 95% CI 10.5 to 33.4, p<0.001). Weight cyclers had a higher mean BMI compared with non-cyclers (mean difference -1.5, 95% CI -2.6 to - 0.4, p= 0.003). Further, the difference in body weight was 6.7 kg (95% CI 2.2 to 10.8, p=0.004) and 10.8 kg (95% CI 5.8 to 15.8, <0.001) in men and women, respectively. Besides BMI status, self-classified overweight/obesity was the strongest predictor of reporting weight cycling (men: OR 5.54, 95% CI 2.03 to 15.12, p<0.01 and women: OR 7.17, 95% CI 2.48 to 20.68, p<0.001).

Conclusion

In novice exercisers, a large proportion reported weight cycling and unhealthy weight control strategies, and both were more prevalent in women than in men. Self-classified overweight was found to be the most important factor influencing weight cycling.

Coronavirus stress and overeating: the role of anxiety and COVID-19 burnout

BACKGROUND

This study examined the role of anxiety and coronavirus disease 2019 (COVID-19) burnout in the relationship between coronavirus stress and overeating among Chinese college students during the COVID-19 pandemic.

METHODS

Chinese college students (N = 2926; M_age = 19.90, SD = 1.47, range = 18-25 years old; 54.34% female) completed self-reported online questionnaires regarding coronavirus stress, anxiety, COVID-19 burnout, and overeating.

RESULTS

Anxiety showed partially indirect effect on the association between coronavirus stress and overeating. COVID-19 burnout exacerbated the indirect pathway between coronavirus stress and overeating via anxiety.

DISCUSSION AND CONCLUSION

This is the first study, to our knowledge, that examines the underlying mechanisms of the coronavirus stress and overeating behavior association among Chinese college students. The results support several existing theories on stress and problematic eating behaviors and provide practical implications for prevention and intervention programs of overeating during the COVID-19 pandemic.

The Role of Impulsivity and Reward Deficiency in "Liking" and "Wanting" of Potentially Problematic Behaviors and Substance Uses

A few studies have examined the changes in substance- and behavior-related "wanting" and "liking" of human subjects, the key properties of Incentive Sensitization Theory (IST). The aim of this study was to examine the dissociation between "wanting" and "liking" as a function of usage frequency, intensity, and subjective severity in individuals across four substances (alcohol, nicotine, cannabis, and other drugs) and ten behaviors (gambling, overeating, gaming, pornography use, sex, social media use, Internet use, TV-series watching, shopping, and work). Also, the potential roles of impulsivity and reward deficiency were investigated in "wanting," "liking," and wellbeing. The sex differences between "wanting" and "liking" were also examined. Based on our findings using structural equation modeling with 749 participants (503 women, M age = 35.7 years, SD = 11.84), who completed self-report questionnaires, "wanting" increased with the severity, frequency, and intensity of potentially problematic use, while "liking" did not change. Impulsivity positively predicted "wanting," and "wanting" positively predicted problem uses/behaviors. Reward deficiency positively predicted problem uses/behaviors, and both impulsivity and problem uses/behaviors negatively predicted wellbeing. Finally, women showed higher levels of "wanting," compared to men. These findings demonstrate the potential roles of incentive sensitization in both potentially problematic substance uses and behaviors.

Stress-induced hyperphagia: empirical characterization of stress-overeaters

Background

Stressful situations can have an impact on an individual’s eating behavior. People vulnerable to the influence of stress tend to change the quantity and quality of their food intake. Variables such as sex and body mass index (BMI) seem to be related to this stress-eating behavior, but it is rather unclear what factors account to the parameters associated with stress-eating behavior. The aim of this survey was to identify further characteristics of adults in Germany related to stress-overeating, focusing on stress perception, coping, eating motives and comfort foods as well as personality types.

Methods

This online survey was performed throughout Germany and comprised a 38-item pre-tested questionnaire. Stress-induced overeating was classified based on the Salzburg Stress Eating Scale (SSES). Moreover, validated questionnaires were used to identify additional characteristics of stress eaters. Participants were recruited using a convenience sampling approach, and data were collected between January and April 2021.

Results

The overall sample consisted of 1222 participants (female 80.8%, aged 31.5±12.8). 42.1% of participants were identified as stress-overeaters. Among the remaining group, 78.9% stated to eat less, 21.1% to eat equally when stressed. Female participants had a higher mean SSES score compared to male participants. The BMI was positively correlated to SSES, r(1220)=0.28, p>0.005. ‘Agreeableness’ (BigFive) was found to be a negative predictor of stress-overeating. The most pronounced difference in eating motives (The Eating Motivation Survey, TEMS) was found for ‘Affect Regulation’ and ‘Weight Control’.

Conclusions

The results indicate that stress-overeating affects a large proportion of the surveyed population. BMI, personality and eating motives additionally characterize stress-overeaters and may contribute to develop new approaches to address unhealthy stress-related eating patterns.

Role of Nociceptin/Orphanin FQ-NOP Receptor System in the Regulation of Stress-Related Disorders

Nociceptin/orphanin FQ (N/OFQ) is a 17-residue neuropeptide that binds the nociceptin opioid-like receptor (NOP). N/OFQ exhibits nucleotidic and aminoacidics sequence homology with the precursors of other opioid neuropeptides but it does not activate either MOP, KOP or DOP receptors. Furthermore, opioid neuropeptides do not activate the NOP receptor. Generally, activation of N/OFQ system exerts anti-opioids effects, for instance toward opioid-induced reward and analgesia. The NOP receptor is widely expressed throughout the brain, whereas N/OFQ localization is confined to brain nuclei that are involved in stress response such as amygdala, BNST and hypothalamus. Decades of studies have delineated the biological role of this system demonstrating its involvement in significant physiological processes such as pain, learning and memory, anxiety, depression, feeding, drug and alcohol dependence. This review discusses the role of this peptidergic system in the modulation of stress and stress-associated psychiatric disorders in particular drug addiction, mood, anxiety and food-related associated-disorders. Emerging preclinical evidence suggests that both NOP agonists and antagonists may represent a effective therapeutic approaches for substances use disorder. Moreover, the current literature suggests that NOP antagonists can be useful to treat depression and feeding-related diseases, such as obesity and binge eating behavior, whereas the activation of NOP receptor by agonists could be a promising tool for anxiety.