Identifying stress-related eating in behavioural research: A review

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.

"Maybe it's Not Just the Food?" A Food and Mood Focus Group Study

Epidemiological and intervention studies in nutritional psychiatry suggest that the risk of mood disorders is associated with what we eat. However, few studies use a person-centred approach to explore the food and mood relationship. In this qualitative study of 50 Australian participants, we explored individuals' experiences with food and mood as revealed during focus group discussions. Using a thematic template analysis, we identified three themes in the food and mood relationship: (i) social context: familial and cultural influences of food and mood, (ii) social economics: time, finance, and food security, and (iii) food nostalgia: unlocking memories that impact mood. Participants suggested that nutrients, food components or food patterns may not be the only way that food impacts mood. Rather, they described the social context of who, with, and where food is eaten, and that time, finances, and access to healthy fresh foods and bittersweet memories of foods shared with loved ones all impacted their mood. Findings suggest that quantitative studies examining the links between diet and mood should look beyond nutritional factors and give increased attention to the cultural, social, economic, and identity aspects of diet.

Chronic stress is associated with reward and emotion-related eating behaviors in college students

Introduction

Stress is related to altered olfactory perception and eating behaviors. The current study investigated the association between chronic stress, food reward and perception of food and non-food odors among college students.

Methods

Sixty-one participants completed the Perceived Stress Scale (PSS) and the Brief Daily Stressors Screening Tool (BDSST). The detective threshold and suprathreshold perception (pleasantness, intensity, and familiarity) of two food (chocolate, strawberry) odors and a non-food (rose) odor were measured. Food reward and macronutrient preference were measured using the computerized Leeds Food Preference Questionnaire and the Macronutrient and Taste Preference Ranking task, respectively. Reward-related eating, emotional eating and eating-related inhibitory control were measured by the Dutch Eating Behavior Questionnaire (DEBQ) and the Reward-Based Eating Drive Scale (RED) scales.

Results

Neither the perceived stress or the severity of daily life stressor exposure was related to odor sensitivity, however, the PSS score was significantly correlated with pleasantness for strawberry odor (r = 0.329, p = 0.013). Chronic stress (PSS and BDSST scores) was significantly correlated with the DEBQ emotional eating and reward-related eating measured by RED (all ps < 0.01). Moreover, the BDSST score was negatively correlated with subjective liking for low-calorie sweet foods (r = -0.46, p < 0.001).

Discussion

Together, our preliminary results suggest disassociated effect of chronic stress on odor perception and eating behaviors.

Food-evoked nostalgia

In three studies, we examined food as an elicitor of nostalgia. Study 1 participants visualised eating either a nostalgic or regularly consumed food. Study 2 participants visualised consuming 12 foods. Study 3 participants consumed 12 flavour samples. Following their food experiences, all participants responded to questions regarding the profile of food-evoked nostalgia (i.e. autobiographical relevance, arousal, familiarity, positive and negative emotions) and several psychological functions (i.e. positive affect, self-esteem, social connectedness, meaning in life). Study 2 and 3 participants also reported their state nostalgia. Results revealed that food is a powerful elicitor of nostalgia. Food-evoked nostalgia has a similar contextual profile to previously examined elicitors, but is a predominantly positive emotional experience. Food-evoked nostalgia served multiple psychological functions and predicted greater state nostalgia.

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.

Interlinking alcohol intake, mental stress, psychotic experiences and job performance of higher institutions' graduates: A structural equation modelling

BACKGROUND

Graduates' job performance has become a matter that needs urgent attention. This is because many stakeholders are increasingly becoming interested in understanding the extent schools are able to produce output that meets the yearnings of society. Along these lines, we examined the contributions of alcohol intake to the job performance of higher education graduates while treating mental stress and psychotic experiences as mediators in the nexus.

MATERIALS AND METHODS

The study's population comprised all the graduates of higher education institutions in Nigeria between 2015 and 2020. Data were collected from a virtual cross-section of 3,862 graduates who self-reported to have taken alcohol in the past. These participants responded to an electronic questionnaire that was mailed to them. The scale content validity for clarity and relevance were 0.90 and 0.88, respectively, while the Cronbach alpha reliability estimate of the instrument is 0.86.

RESULTS

Amongst many others, key findings indicate that alcohol intake, mental stress and psychotic experiences jointly made a significant negative contribution to the overall job performance of graduates (R ² = 0.256, 95% confidence interval (CI) [0.23, 0.28], P = 0.00). Mental stress (B = -0.09, β = -0.14, z = -4.45, 95%CI [-0.24, -0.05], P = 0.00) and psychotic experiences (B = -0.26, β = -0.43, z = -8.07, 95%CI [-0.68, -0.16], P = 0.01) have significant negative contributions to graduates' job performance, respectively. Alcohol intake and mental stress jointly predict the psychotic experiences of graduates (B = -0.26, β = -0.43, z = -8.07, 95%CI [-0.68, -0.16], P = 0.01). Alcohol intake has a positive contribution to the mental stress of graduates (R ² = 0.797, 95%CI [0.77, 0.825], P = 0.01). Mental stress and psychotic experiences jointly mediated the relationship between alcohol intake and graduates' job performance.

CONCLUSION

It was concluded that high intake of alcohol and high levels of mental stress and psychotic experiences significantly reduce graduates' job performance generally and in specific aspects. Alcohol intake can increase graduates' job performance to a small extent depending on the amount consumed.

SHORT TERM EFFECTS OF SEMAGLUTIDE ON EMOTIONAL EATING AND OTHER ABNORMAL EATING PATTERNS AMONG SUBJECTS LIVING WITH OBESITY

OBJECTIVE

Emotional eating (EE) and other abnormal eating patterns are highly prevalent among people living with obesity (PWO). In this sense, semaglutide, by acting on areas of the brain involved in the reward system and emotion regulation, could have the potential to ameliorate these eating patterns.

METHOD

69 PWO attending an obesity clinic were evaluated baseline and after 3 months since the beginning of semaglutide. To rule out abnormal EE, the Emotional Eating Questionnaire was administered, and a structured interview was conducted.

RESULTS

69 PWO (82.6%♀, 43.7±1years, and 34.3±6kg/m 2) were included. After 3 months of semaglutide, there was a significant reduction in weight (96.1±20.9 vs 91.3±19.7kg; p<0.001) and BMI (34.3±6 vs 32.4±5.6kg/m 2; p<0.0001). The proportion of patients with EE (72.5% vs 11.5%; p<0.001), external eating (27.5% vs 10.1%; p<0.001) cravings (49.3% vs 21.7%; p<0.001) and savory cravings (53.6% vs 14.5%; p<0.001) was significantly reduced after 3 months of semaglutide. Also, the proportion of PWO with regular exercise was increased (15.9% vs 39.1%; p<0.001). However, Logistic regression analysis showed that only sweet cravings at baseline were the only factor associated, although not significant, with a poorer weight loss (p=0.05).

DISCUSSION

Semaglutide is an effective weight-loss treatment in PWO at short term. Moreover, semaglutide was highly effective in ameliorating EE and other abnormal eating patterns that exert a negative influence on weight.

Direct Yet Opposite Effects of Stress-related and Mindful Eating on Diet Quality

OBJECTIVE

Examine the relationships among dietary quality, mindful eating, and constructs of the Transactional Model of Stress and Coping.

METHODS

In this cross-sectional study, women (n = 67) aged 25-50 years, with a body mass index of 25-40 kg/m² completed 3 days of 24-hour recalls and a survey that included the Perceived Stress Scale, Eating and Appraisal Due to Emotions and Stress Questionnaire, and the Mindful Eating Questionnaire. Structural equation modeling assessed relationships among all constructs with the dependent variable, the Healthy Eating Index-2015.

RESULTS

Mindful Eating Questionnaire (β = 0.60, P = 0.001) and Emotion and Stress-related Eating scores from Eating and Appraisal Due to Emotions and Stress Questionnaire (β = -0.69, P < 0.001) (r² = 0.50) were directly associated with Healthy Eating Index-2015, but no indirect effects were identified.

CONCLUSIONS AND IMPLICATIONS

Overall dietary quality is associated with greater mindful eating but more emotion and stress-related eating scores among women who were overweight or obese. Future studies could assess model constructs using other diet quality scores and including additional coping mechanisms such as substance use, physical activity, and meditation.

Gut-brain mechanisms underlying changes in disordered eating behaviour after bariatric surgery: a review

Bariatric surgery results in long-term weight loss and an improved metabolic phenotype due to changes in the gut-brain axis regulating appetite and glycaemia. Neuroendocrine alterations associated with bariatric surgery may also influence hedonic aspects of eating by inducing changes in taste preferences and central reward reactivity towards palatable food. However, the impact of bariatric surgery on disordered eating behaviours (e.g.: binge eating, loss-of-control eating, emotional eating and 'addictive eating'), which are commonly present in people with obesity are not well understood. Increasing evidence suggests gut-derived signals, such as appetitive hormones, bile acid profiles, microbiota concentrations and associated neuromodulatory metabolites, can influence pathways in the brain implicated in food intake, including brain areas involved in sensorimotor, reward-motivational, emotional-arousal and executive control components of food intake. As disordered eating prevalence is a key mediator of weight-loss success and patient well-being after bariatric surgery, understanding how changes in the gut-brain axis contribute to disordered eating incidence and severity after bariatric surgery is crucial to better improve treatment outcomes in people with obesity.

Self-reported emotional eaters consume more food under stress if they experience heightened stress reactivity and emotional relief from stress upon eating

Group data means from individuals who self-assess as emotional eaters do not reliably show increased food intake in response to stress or negative emotions. This inconsistency in predictive validity of self-reported emotional eating (EE) could be attributable to unconsidered moderation of the relationship between self-reported EE and behavioral measures of EE. Greater emotional relief from stress by eating may provide enhanced negative reinforcement and promote future EE in response to stress as a form of self-medication. Thus, we predicted that greater emotional relief from stress by eating (decrease in negative affect from stress to post-eating) would moderate the extent to which heightened stress reactivity (measured by systolic blood pressure, SBP) moderates the relationship between self-reported EE and food intake post-stress. We also hypothesized that self-reported EE would not predict greater food consumption on the rest day. 43 undergraduate women completed online assessments of eating behaviors. Participants were given snacks to eat after a mental stress task (TSST) or rest period on separate days in counterbalanced order. Our prediction was supported, as the moderated moderation model (PROCESS model 3) was highly significant on the stress day. Self-reported EE predicted increased food intake post-stress only under conditions of high stress reactivity and high emotional relief. On the rest day, self-reported EE predicted greater snack food intake only when SBP was high. This conditional increased intake substantiates stress as a promoter of snack food consumption for women with greater EE. Overall, our findings identified factors that may distinguish the subset of self-reported emotional eaters who are more likely to display EE behaviors in a laboratory setting, yet further studies are needed to directly test whether negative reinforcement via emotional relief from stress by eating drives enhanced EE following stress.

Potential gut-brain mechanisms behind adverse mental health outcomes of bariatric surgery

Bariatric surgery induces sustained weight loss and metabolic benefits via notable effects on the gut-brain axis that lead to alterations in the neuroendocrine regulation of appetite and glycaemia. However, in a subset of patients, bariatric surgery is associated with adverse effects on mental health, including increased risk of suicide or self-harm as well as the emergence of depression and substance use disorders. The contributing factors behind these adverse effects are not well understood. Accumulating evidence indicates that there are important links between gut-derived hormones, microbial and bile acid profiles, and disorders of mood and substance use, which warrant further exploration in the context of changes in gut-brain signalling after bariatric surgery. Understanding the basis of these adverse effects is essential in order to optimize the health and well-being of people undergoing treatment for obesity.

The therapeutic potential of GLP-1 analogues for stress-related eating and role of GLP-1 in stress, emotion and mood: a review

Stress and low mood are powerful triggers for compulsive overeating, a maladaptive form of eating leading to negative physical and mental health consequences. Stress-vulnerable individuals, such as people with obesity, are particularly prone to overconsumption of high energy foods and may use it as a coping mechanism for general life stressors. Recent advances in the treatment of obesity and related co-morbidities have focused on the therapeutic potential of anorexigenic gut hormones, such as glucagon-like peptide 1 (GLP-1), which acts both peripherally and centrally to reduce energy intake. Besides its appetite suppressing effect, GLP-1 acts on areas of the brain involved in stress response and emotion regulation. However, the role of GLP-1 in emotion and stress regulation, and whether it is a viable treatment for stress-induced compulsive overeating, has yet to be established. A thorough review of the pre-clinical literature measuring markers of stress, anxiety and mood after GLP-1 exposure points to potential divergent effects based on temporality. Specifically, acute GLP-1 injection consistently stimulates the physiological stress response in rodents whereas long-term exposure indicates anxiolytic and anti-depressive benefits. However, the limited clinical evidence is not as clear cut. While prolonged GLP-1 analogue treatment in people with type 2 diabetes improved measures of mood and general psychological wellbeing, the mechanisms underlying this may be confounded by associated weight loss and improved blood glucose control. There is a paucity of longitudinal clinical literature on mechanistic pathways by which stress influences eating behavior and how centrally-acting gut hormones such as GLP-1, can modify these. (250).

Relationships among perceived stress, emotional eating, and dietary intake in college students: Eating self-regulation as a mediator

This study aimed to examine the relationships among perceived stress, eating self-regulation, emotional eating, and dietary intake among undergraduate college students. This cross-sectional study was conducted with 523 students recruited from Amazon Mechanical Turk. All participants completed an online survey that assessed perceived stress, eating self-regulation, emotional eating, dietary intake, and demographics. The study sample was 47% female, 30% Hispanic, 8% Black, and 33% Asian. The overweight and obesity rate was 33%. Nearly 83% reported having moderate to high levels of stress, and over 80% had low to medium levels of eating self-regulation skills. On average, students consumed fruits and vegetables 2.42 times per day and sweets and soft drinks about once every other day. Perceived stress was positively correlated with emotional eating (β = 0.12, p = .005), and negatively correlated with eating self-regulation (β = -0.40, p < .001). Eating self-regulation partially mediated the relationship between perceived stress and emotional eating (β = 0.11, p < .001). Emotional eating was positively related to intake of sweets and soft drinks. Eating self-regulation was negatively related to sweet intake (β = -0.19, p < .001). Eating self-regulation and emotional eating fully mediated the relationship between perceived stress and sweet intake (β = 0.09, p < .001). Although warranting further investigation, this study's results emphasize the significant protective role of eating self-regulation for controlling college students' intake of sweets and soft drinks, and the negative effects of perceived stress and emotional eating on their dietary intake. Future interventions could consider strategies focusing on stress management and eating self-regulation to improve dietary intake among this young population.