Stress-induced eating: Fact, fiction or misunderstanding?

Cariogenic diet consumption during lockdown

BACKGROUND

During stressful situations such as pandemic-associated lockdowns, individuals' diets may change towards (cariogenic) 'comfort food'. This study assessed the dietary patterns during the lockdown in the Colombian population.

METHODS

A cross-sectional online survey was designed. A convenience sample of 489 adults was drawn, with 50% of them being in COVID-19 lockdown and the other being not or only partially in lockdown. The questionnaire collected data about the type and frequency of food consumed, with a special focus on cariogenic (i.e., rich in free sugars and starches) food. Descriptive analyses were performed, and a generalised linear model was estimated to predict the frequency of cariogenic diet consumption in this period of time.

RESULTS

Sweet whole wheat bread (38.2%, p = 0.005), flavoured milk (26.4%, p = 0.002), sugar-sweetened bubble gums (39.8%, p = 0.001), toffees (35.4%, p = 0.004), soft candies (e.g., gums) (35.4%, p = 0.018), chocolates (55.3%, p = 0.017), filled doughnuts (28.5%, p = 0.013) or grapes (51.2%, p = 0.002) were significantly consumed more during the lockdown. Multivariable generalised linear modelling showed being single, having children and being in lockdown were significantly associated with higher frequency of cariogenic food consumption.

CONCLUSIONS

Lockdown was found to be associated with detrimentally altered food consumption patterns and, specifically, a more cariogenic diet. Healthcare professionals should consider this when reopening services, and political decision-makers may want to reflect on the unwarranted side effect of lockdown.

Specifics of the Emotional Response of Patients Suffering From Major Depressive Disorder to Imagined Basic Tastes of Food

Nowadays, the major depressive disorder (MDD) is a common disease that negatively affects the life quality of many people around the world. As MDD symptoms are closely related with the changes in food and eating, the relation between patients’ emotional responses and food tastes could be used as criteria for diagnostic. Until now, studies on the emotional response to different food tastes for patients affected by MDD have been poorly described in literature. Therefore, the aim of this study was to evaluate the emotional response of patients suffering from MDD to the imagined different food tastes and to compare the results with a control group. Emotional responses in tested participants were induced by using cards with words of basic food tastes such as “sweet,” “salty,” “bitter,” “sour,” and “neutral.” The assessment of emotional response was performed with FaceReader 6 software. The outcome of this study showed that participants with MDD expressed lower “happy” and “contempt” and higher “surprised” emotions, along with a higher negative valence mean, in comparison with controls for all tested basic tastes of food (p ≤ 0.05). When Likert scale was used, significant differences (p ≤ 0.001) in response were only found for “sour” and “salty” imaginary tastes between healthy group and patients with MDD. The findings of this study provide the additional data on food–associated emotion analysis of MDD patients and could be useful for the further development of the contactless method for early diagnosis of MDD.

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

Disordered eating is often associated with marked psychological and emotional distress, and severe adverse impact on quality of life. Several factors can influence eating behavior and drive food consumption in excess of energy requirements for homeostasis. It is well established that stress and negative affect contribute to the aetiology of eating disorders and weight gain, and there is substantial evidence suggesting sex differences in sub-clinical and clinical types of overeating. This review will examine how negative affect and stress shape eating behaviors, and how the relationship between the physiological, endocrine, and neural responses to stress and eating behaviors differs between men and women. We will examine several drivers of overeating and explore possible mechanisms underlying sex differences in eating behavior.

"Better If They Laugh with Me than at Me": The Role of Humor in Coping with Obesity-Related Stigma in Women

This study investigated the role of perceived stigmatization in the relationship between humor styles and coping with stress among young women suffering from stigma due to obesity. In the 21st century, obesity is an increasing global health issue with many physical and mental consequences for obese women. As a chronic stigmatizing disease, it requires that the affected individuals cope with social consequences; women with obesity are more prone to such consequences than men. Humor fosters the breaking of stereotypes and alleviating the consequences of stigmatization. A total of 127 young adult women (age M = 25.74, SD = 2.73) participated in the study (n = 54 with overfat and n = 73 with healthy fat). Participants filled out the Humor Styles Questionnaire, Perceived Stigmatization Questionnaire, and the Brief COPE Scale. Anthropometric data were gathered using a body composition analyzer. Results indicate that, when perceiving hostile behaviors toward themselves and using humor as a coping strategy, women with overfat select maladaptive styles of humor (i.e., self-defeating and aggressive styles). Women with overfat were also more likely to use humor as a coping strategy in difficult situations. Furthermore, none of the participants were satisfied with their body mass. At the same time, among women without obesity, a lack of compliments was not treated as a problem, even if they had high body fat.

Lifelong enhancement of body mass from adolescent stress in male hamsters

In hamsters, exposure to stress in adulthood causes increased body weight. We addressed how social stress during puberty would impact food intake and body weight. Stressed hamsters started gaining significantly more weight than controls after only two days of stress exposure. Over a two-week period, stressed subjects gained 10% more weight and consumed more food than controls. At the end of the stress period, stressed hamsters collected nearly twice as many palatable sugar pellets from an arena than controls. Stressed subjects presented 15-20% more body fat in mesenteric, inguinal, and retroperitoneal fat pads. In order to assess the duration of these effects, we analyzed data from previous studies keeping hamsters for over two months past the stress period in puberty. Our analysis shows that stressed hamsters stopped gaining more weight after the stress period, but their body weights remained elevated for over two months, consistently weighing 10% more than their non-stressed counterparts. We also analyzed conditioning training data collected after the period of stress in late puberty and early adulthood (P56 to P70) that was part of the original studies. Training consisted of lever pressing for palatable food rewards. At these times, previously stressed hamsters retrieved similar numbers of food pellets from the conditioning chambers, suggesting no difference in appetite after the stress period. These data showing a long-lasting effect of stress on body weight may be relevant to studies on the ontogeny of lifelong obesity.

Eating styles profiles in Chilean women: A latent Profile analysis

The aims of this study were to identify profiles of women based on their levels of emotional, external and restraint eating, and to determine differences in these eating styles profiles based on nutritional status, sociodemographic characteristics, stress, social support, and satisfaction with the body image. Questionnaires were administered to 884 women aged 20 to 60 living in two Chilean cities. Questionnaires included the Dutch Eating Behavior Questionnaire (DEBQ), the Medical Outcomes Study-Social Support Survey, and the Perceived Stress Scale (PSS). Satisfaction with body image was assessed using a body-image-related single question. Nutritional status and sociodemographic characteristics were also assessed. Latent Profile Analysis (LPA) was used to identify profiles based on the three eating styles measured by the DEBQ. LPA allowed to distinguish four eating styles profiles: "women with medium emotional and external eating, high dietary restraint" (Profile 1, 36.64%); "women with low emotional, external and restraint eating" (Profile 2, 25.25%), "women with high emotional, external and restraint eating" (Profile 3, 21.85%); and "women with very low emotional and external eating, low dietary restraint" (Profile 4, 16.26%). Profile 1 had a greater proportion of women moderately satisfied with their body image. Profiles 2 and 4 scored higher in perceived social support and had greater proportions of women satisfied with their body image. Profile 4 had a higher proportion of married or cohabiting women. Profile 3 scored higher in the PSS and had higher proportion of obese and unsatisfied with their body image women. These results suggest that interventions to reduce emotional, external and restraint eating should not only involve the women, but also their family members.

Emotional eating, binge eating, physical inactivity, and vespertine chronotype are negative predictors of dietary practices during COVID-19 social isolation: A cross-sectional study

Objectives

Coronavirus disease 2019 (COVID-19) emerged and rapidly spread worldwide. Several countries have imposed lockdown and isolation in attempt to mitigate viral spread. However, social isolation has a negative effect on psychological aspects, increasing stress, fear, anxiety, anger and emotional disturbance, as well as affecting sleep pattern and the practice of physical activity. Negative emotions and lifestyle changes trigger overeating, consequently affecting dietary practices. The aim of this study was to verify the prevalence of lifestyle factors (i.e., sleep time/quality and practice of physical exercise), eating behavior dimensions, chronotype, and association with dietary practices (planning, domestic organization, food choice, ways of eating) in home confinement during the COVID-19 pandemic in São Paulo, Brazil.

Methods

This cross-sectional study was conducted between April 27 and May 25, 2020. An anonymous online questionnaire (Microsoft Forms) was used for data collection by the snowball method. We verified dietary practices (outcome), eating behavior, physical exercise practice, sleep quality and duration, and chronotype (exposure variables). Sex, age, educational and social status were assessed as covariates and confounders. We evaluated 724 adults (585 women and 139 men). Mean age was 32.6 y (±11.3) for women and 33.5 y (±10.5) for men.

Results

Emotional eating (EE) and binge eating (BE) were positively correlated (r = 0.66; P <0.001). Dietary practices were negatively correlated with BE (r = –0.41; P <0.001), EE (r = –0.33; P <0.001) and body mass index (r = –0.24; P <0.001). Linear regression demonstrated that EE (β = –0.1351; t = –2.841; P = 0.005; η_p² = 0.013), BE (β = –0.2580; t = –5.612; P < 0.001; η_p² = 0.050), no practice of physical exercise at home (β = –0.4271; t = –5.933; P < 0.001; η_p² = 0.055), being vespertine (β = –0.3435; t = 2.076; P = 0.038; η_p² = 0.019), and age (β = –0.082; t = –2.210; P = 0.027; η_p² = 0.008) are negative predictors of dietary practices. Finally, cognitive restraint (β = 0.1407; t = 3.858; P < 0.001; η_p² = 0.024), better sleep quality (β = 0.1768; t = 2.506; P = 0.012; η_p² = 0.010), receiving 4–10 wages per month (according to a minimum wage in Brazil that corresponds to US $ 183.01) (β = 0.2568; t = 2.573; P = 0.10; η_p² = 0.027) and 10 – 20 wages per month (β = 0.4490; t = 3.726; P < 0.001; η_p² = 0.027) are positive predictors of dietary practices.

Conclusion

Eating behavior, physical exercise, sleep, and social factors can be important predictors for dietary practices during COVID-19 social confinement. Longitudinal studies in Brazil are needed to confirm these findings.

Exploring Abnormal Behavior Patterns of Online Users With Emotional Eating Behavior: Topic Modeling Study

Background

Emotional eating (EE) is one of the most significant symptoms of various eating disorders. It has been difficult to collect a large amount of behavioral data on EE; therefore, only partial studies of this symptom have been conducted. To provide adequate support for online social media users with symptoms of EE, we must understand their behavior patterns to design a sophisticated personalized support system (PSS).

Objective

This study aimed to analyze the behavior patterns of emotional eaters as the first step to designing a personalized intervention system.

Methods

The machine learning (ML) framework and Latent Dirichlet Allocation (LDA) topic modeling tool were used to collect and analyze behavioral data on EE. Data from a subcommunity of Reddit, /r/loseit, were analyzed. This dataset included all posts and feedback from July 2014 to May 2018, comprising 185,950 posts and 3,528,107 comments. In addition, deleted and improperly collected data were eliminated. Stochastic gradient descent–based ML classifier with an accuracy of 90.64% was developed to collect refined behavioral data of online users with EE behaviors. The expert group that labeled the dataset to train the ML classifiers included a medical doctor specializing in EE diagnosis and a nutritionist with profound knowledge of EE behavior. The experts labeled 5126 posts as EE (coded as 1) or others (coded as 0). Finally, the topic modeling process was conducted with LDA.

Results

The following 4 macroperspective topics of online EE behaviors were identified through linguistic evidence regarding each topic: addressing feelings, sharing physical changes, sharing and asking for dietary information, and sharing dietary strategies. The 5 main topics of feedback were dietary information, compliments, consolation, automatic bot feedback, and health information. The feedback topic distribution significantly differed depending on the type of EE behavior (overall P<.001).

Conclusions

This study introduces a data-driven approach for analyzing behavior patterns of social website users with EE behaviors. We discovered the possibility of the LDA topic model as an exploratory user study method for abnormal behaviors in medical research. We also investigated the possibilities of ML- and topic modeling–based classifiers to automatically categorize text-based behavioral data, which could be applied to personalized medicine in future research.

Negative affect is associated with increased stress-eating for women with high perceived life stress

Perceived life stress (PLS) and cognitive restraint are associated with increased comfort food intake under stress and lead to weight gain and obesity, but the mechanisms by which they do so remain unclear. Stress and negative affect (NA) are associated with increased reward-driven comfort food intake as a means to 'feel better', particularly for individuals with higher PLS and cognitive restraint. Thus, we propose that PLS and cognitive restraint increase stress-eating by strengthening the relationship between stress-induced NA and comfort food intake. Upon comfort eating, individuals with higher PLS show greater reductions in the negative consequences of stress (e.g. NA). The rewarding effects of this 'emotional relief' may promote future stress-induced comfort eating, but this has yet to be examined. Thus, we investigate the pathways by which PLS or cognitive restraint increase snack intake under stress by proposing that 1) stress-induced NA is a stronger predictor of increased snack intake for women with greater PLS and cognitive restraint, and 2) greater PLS will be associated with greater reductions in NA upon snacking under stress (i.e. emotional relief). Forty-three healthy women were given snacks (chips, golden oreos, and M&Ms) to eat after a Trier Social Stress Test or rest period on separate days in counterbalanced order. Following linear regression analyses, we determined that stress-induced NA predicted more snack intake for women with higher PLS, and that higher PLS was associated with heightened emotional relief upon snacking under stress. Future studies are needed to directly assess whether greater emotional relief following stress-eating reinforces the learned association between stress-induced NA and intake, and ultimately explains greater stress-eating and obesity in women with higher PLS. This work may lead clinicians to focus on NA in the treatment of obesity-and stress-related illnesses for women with higher PLS.

Stress-mediated quality of life outcomes in parents of disabled children: A case-control study

BACKGROUND

The purpose of the present study was to resolve whether caregiving for a child with disability influences the physical and mental health of the caregivers and whether stress is related to the quality of life of the caregivers.

METHODS

The Parental Stress Scale questionnaire for the assessment of parental stress and the Short Form-12 version 2 questionnaire for the assessment of physical and mental health quality of life were distributed among 69 parents of developmentally disabled children and 137 parents of healthy children (control group). Various sociodemographic factors were also included.

RESULTS

A significant difference was seen between the two groups in terms of employment, presence of disabled sibling, smoking, and physical activity. Parents of developmentally disabled children had significantly higher stress levels and worse mental health-related quality of life. Overall physical health quality of life was similar between cases and controls. Stress had a negative correlation with both mental and physical health quality of life of the parents.

CONCLUSION

Stress related to raising a child with disability negatively influences the parental quality of life. Stress management aiming at its prevention and reduction might be significant aspects of intervention for the improvement of the quality of life of the caregivers.

Attachment Style and Obesity: Disordered Eating Behaviors as a Mediator in a Community Sample of Canadian Youth

OBJECTIVE

Obesity and overweight are associated with many negative health outcomes. Attachment style has been implicated in the development of obesity in youth. The present study examined if disordered eating behaviors mediate the relationship between attachment style and body mass index (BMI) in a large community sample of Canadian youth.

METHOD

A total of 3,043 participants (1,254 males and 1,789 females, Mage = 14.20 years) completed self-report questionnaires including the Relationship Questionnaire and the Dutch Eating Behavior Questionnaire, and BMI was objectively measured. Disordered eating behaviors (restrained, emotional, and external) were examined as possible mediating mechanisms in the relationship between attachment style and BMI z-score, using a multiple mediation model using bootstrapping while controlling for socio-demographic covariates.

RESULTS

Insecure attachment was significantly associated with higher BMI, and disordered eating mediated this relationship. Restrained eating was the strongest mediator of this pathway.

CONCLUSION

Results suggest that it may be important to take attachment history and restrained eating into account when designing treatment and prevention strategies for obesity in youth.

Italian version of the Dutch Eating Behavior Questionnaire. Psychometric proprieties and measurement invariance across sex, BMI-status and age

The purpose of this study was to examine the basic psychometric proprieties of the Dutch Eating Behavior Questionnaire (DEBQ) and its measurement invariance across sex, BMI-status (normal weight/overweight), and age in a community sample of 990 Italian adults. The analysis of the dimensionality of the DEBQ using exploratory factor analysis revealed the existence of three major factors - emotional, restrained and external eating. Single and multi-group confirmatory factor analyses replicated the three-factor structure, and this dimensional structure proved to be invariant across sex, BMI-status, and age. Findings upheld the criterion-related validity (e.g., via its associations with Eating Attitudes Test-26). The DEBQ's subscales displayed high internal consistency and test-retest reliability over a 4-week period. Statistically significant differences were found when sex, BMI and age groups are compared in the latent means of emotional, external and restrained eating and they are discussed with reference to theory, past and recent empirical findings. Overall, results support the measurement invariance of the DEBQ and suggest that the Italian version is a psychometrically reliable, valid and useful measurement instrument for assessing adult eating behaviors.

Effect of salidroside, active principle of Rhodiola rosea extract, on binge eating

Stress is a key determinant of binge eating (BE). Since Rhodiola rosea is known to modulate stress responses, its effect in a model of BE was investigated. BE for highly palatable food (HPF) was evoked in female rats by three 8-day cycles of food restriction/re-feeding (for 4days 66% of the usual chow intake; for 4days food ad libitum) and acute stress on the test day (day 25). R. rosea dry extract (3% rosavin, 3.12% salidroside) or its active principles were given by gavage 1h before access to HPF. Only rats exposed to both food restrictions and stress exhibited BE in the first 15-60min after the stressful procedure. R. rosea extract 10mg/kg significantly reduced and 20mg/kg abolished the BE episode. R. rosea extract 20mg/kg abolished also stress-induced increase in serum corticosterone levels. The R. rosea active principle salidroside, but not rosavin, at doses present in the extract, dose-dependently reduced or abolished BE for the period in which it was elicited. In conclusion results indicate that R. rosea extracts may have therapeutic properties in bingeing-related eating disorders and that salidroside is the active principle responsible for this effect.

A preclinical model of binge eating elicited by yo-yo dieting and stressful exposure to food: effect of sibutramine, fluoxetine, topiramate, and midazolam

RATIONALE

Preclinical models are needed to investigate the neurobiology and psychobiology of binge eating and to identify innovative pharmacotherapeutic strategies.

OBJECTIVES

A modification of the model based on the combination of cyclic caloric restrictions and acute stress was developed to further increase its face validity and reliability and, for the first time, to assess its predictive value.

MATERIALS AND METHODS

Four groups of female rats were employed: group 1 was normally fed and not stressed on the test day (25th); group 2 was fed normally but was exposed to an acute stress on day 25; group 3 was exposed to three cycles (4 days 66% of chow intake + 4 days food ad libitum) of yo-yo dieting but not stressed; and group 4 was exposed to cyclic yo-yo dieting and then stressed. All groups were fed highly palatable food (HPF) for 2 h on days 5-6 and 13-14. Acute stress was elicited by exposing rats to HPF, but preventing them from access to it for 15 min.

RESULTS

The combination of cyclic food restriction and stressful exposure to food markedly increased HPF intake. Sibutramine and fluoxetine inhibited food intake in all conditions. Topiramate selectively inhibited compulsive HPF intake in rats submitted to caloric restriction and stress. Midazolam increased HPF intake.

CONCLUSIONS

Pharmacological results suggest that this model, in addition to face validity as an isomorphic model of human binge eating, is endowed with good predictive validity.

Reported food choices in older women in relation to body mass index and depressive symptoms

This paper examines the relationships among reports of depressive symptoms, BMI and frequency of consumption of 30 foods in 4655 middle-aged women. Food was grouped into three categories: high-calorie sweet, high-calorie nonsweet, and low-calorie. Controlling for total energy intake, BMI and depressive symptoms were both inversely associated with a higher frequency of consumption of low-calorie foods. BMI was positively associated with consumption of high-calorie nonsweet foods and negatively related to consumption of high-calorie sweet foods. Depressive symptoms were positively associated with sweet foods consumption and negatively associated with nonsweet foods consumption. These findings suggest that the positive association between BMI and depression in women may be mediated by sweets consumption. This is consistent with the hypothesis that eating sweet foods reduces negative affect.

How emotions affect eating: a five-way model

Despite the importance of affective processes in eating behaviour, it remains difficult to predict how emotions affect eating. Emphasizing individual differences, previous research did not pay full attention to the twofold variability of emotion-induced changes of eating (variability across both individuals and emotions). By contrast, the present paper takes into account both individual characteristics and emotion features, and specifies five classes of emotion-induced changes of eating: (1) emotional control of food choice, (2) emotional suppression of food intake, (3) impairment of cognitive eating controls, (4) eating to regulate emotions, and (5) emotion-congruent modulation of eating. These classes are distinguished by antecedent conditions, eating responses and mediating mechanisms. They point to basic functional principles underlying the relations between emotions and biologically based motives: interference, concomitance and regulation. Thus, emotion-induced changes of eating can be a result of interference of eating by emotions, a by-product of emotions, and a consequence of regulatory processes (i.e., emotions may regulate eating, and eating may regulate emotions).

Effects of distress, alexithymia and impulsivity on eating

OBJECTIVE

To improve our understanding of possible mechanisms underlying emotional overeating this study examined the effects of a distress manipulation on food intake in relation to alexithymia and impulsivity.

METHOD

Participants were 86 females who were subjected to a distress manipulation (the anticipation of a public speaking task) prior to an ad lib taste task and filled out questionnaires on impulsivity and the alexithymia constructs difficulty identifying and describing feelings.

RESULTS

Alexithymia significantly (p<.05) moderated the relationship between food consumption and distress. Instead of eating less in the distress condition, alexithymic females ate the same or even more, this showing a 'biological unnatural' and 'inapt' response.

CONCLUSION

Findings suggest that for the 'natural' distress response (reduction of food intake) good ability to identify and describe feelings to others is required, and that the presence or absence of these abilities may predict which people respond to distress by undereating or by overeating. The results provide empirical support for Bruch's conceptualisation of poor interoceptive awareness as possible predictive factor for emotional overeating.

Work stress, weight gain and weight loss: evidence for bidirectional effects of job strain on body mass index in the Whitehall II study

OBJECTIVE

Previous research has focused on overall associations between work stress and body mass index (BMI) ignoring the possibility that stress may cause some people to eat less and lose weight and others to eat more. Using longitudinal data, we studied whether work stress induced weight loss in lean individuals and weight gain in overweight individuals.

DESIGN

Prospective cohort study.

SUBJECTS

A total of 7965 British civil servants (5547 men and 2418 women) aged 35-55 at study entry (The Whitehall II study).

MEASUREMENTS

Work stress, indicated by the job strain model and measured as job control, job demands and job strain, was assessed at baseline and BMI at baseline and at 5-year follow-up.

RESULTS

In men, the effect of job strain on weight gain and weight loss was dependent on baseline BMI (P</=0.03). In the leanest quintile (BMI<22 kg/m(2)) at baseline, high job strain and low job control were associated with weight loss by follow-up, whereas among those in the highest BMI quintile (>27 kg/m(2)), these stress indicators were associated with subsequent weight gain. No corresponding interaction was seen among women.

CONCLUSION

Inconsistent findings reported by previous studies of stress and BMI have generally been interpreted to indicate the absence of an association. In light of our results, the possibility of differential effects of work stress should also be taken into account.

Emotional influences on food choice: sensory, physiological and psychological pathways

Sensory, physiological and psychological mechanisms are reviewed that underlie emotional influences on food choice. Both moods and emotions are considered. Eating a meal will reliably alter mood and emotional predisposition, typically reducing arousal and irritability, and increasing calmness and positive affect. However, this depends on the meal size and composition being close to the eater's habit, expectations and needs. Unusual meals--e.g. too small, unhealthy--may negatively affect mood. Sweetness, and sensory cues to high energy density, such as fatty texture, can improve mood and mitigate effects of stress via brain opioidergic and dopaminergic neurotransmission. However, adaptation in these pathways, perhaps enhanced by inherited sensitivity, with chronic exposure to such sensory qualities, could lead to overeating of energy-dense foods and consequent obesity. Sweet, fatty foods low in protein may also provide alleviation from stress in vulnerable people via enhanced function of the serotonergic system. Moreover, in rats, such foods seem to act as part of a feedback loop, via release of glucocorticoid hormones and insulin, to restrain activity of the hypothalamic pituitary adrenal axis during stress. However, this effect is also associated with abdominal obesity. In humans, a number of psychological characteristics predict the tendency to choose such foods when stressed, such as restrained or emotional eating, neuroticism, depression and premenstrual dysphoria, all of which could indicate neurophysiological sensitivity to reinforcing effects of such foods. Greater understanding of such predictive traits and the underlying mechanisms could lead to tailoring of diet to meet personal emotional needs.

Emotionsbedingtes Essverhalten: Die Bedeutung der Emotionen

Zusammenfassung. Wirkungen von Emotionen auf das Essverhalten variieren in Abhängigkeit von Person- und Emotionsmerkmalen. Bisherige Untersuchungen waren größtenteils auf den Einfluss von Personmerkmalen gerichtet. Sie zeigten, dass ein gezügelter sowie ein emotionaler Ess-Stil zu gesteigerter Nahrungsaufnahme bei negativen Emotionen prädisponieren. Weitere Untersuchungen verweisen auf den Einfluss von Emotionsmerkmalen wie Intensität und Valenz. Der vorliegende Beitrag fasst den Forschungsstand zusammen und unterteilt die Wirkungen von Emotionen auf das Essverhalten in fünf Varianten, die sich durch definierte Person- und Emotionsmerkmale vorhersagen lassen: emotionale Steuerung der Nahrungswahl, emotionale Hemmung des Essverhaltens, emotionale Enthemmung gezügelten Essverhaltens, emotional-instrumentelles Essverhalten und emotionkongruente Modulation des Essverhaltens.

Stress and dietary practices in adolescents

Baseline data from the Health and Behavior in Teenagers Study (HABITS) were used to investigate associations between stress and dietary practices in a socioeconomically and ethnically diverse sample of 4,320 schoolchildren (mean age = 11.83 years). Male (n = 2,578) and female (n = 1,742) pupils completed questionnaire measures of stress and 4 aspects of dietary practice (fatty food intake, fruit and vegetable intake, snacking, and breakfast consumption) and also provided demographic and anthropometric data. Multivariate analyses revealed that greater stress was associated with more fatty food intake, less fruit and vegetable intake, more snacking, and a reduced likelihood of daily breakfast consumption. These effects were independent of individual (gender, weight) and social (socioeconomic status, ethnicity) factors. Stress may contribute to long-term disease risk by steering the diet in a more unhealthy direction.

Chocolate eating in healthy men during experimentally induced sadness and joy

The study compared influences of qualitatively different emotions on eating. Motivation to eat, affective responses to chocolate and chewing of chocolate were investigated in healthy normal weight males during experimentally induced emotions. Subjects abstained from eating 2 h (n = 24) or 8 h (n = 24) before testing. They received pieces of chocolate after viewing film clips presented to induce anger, fear, sadness and joy. Motivation to eat and most affective responses to eating chocolate were higher after 8 h than after 2 h of deprivation. Sadness and joy affected motivation to eat in opposite directions: joy increased and sadness decreased appetite (p < 0.001). In joy, a higher tendency to eat more chocolate was reported (p < 0.001), and chocolate tasted more pleasant (p < 0.001) and was experienced as more "stimulating" than in sadness (p < 0.01). No effects of deprivation could be found for chewing time and number of chews. Results indicate that the quality of emotions can affect motivation to eat and affective responses to eating chocolate. Our findings on decreased eating responses to sadness in healthy males and the contradictory increased eating responses to sadness reported by others supports two types of emotion-induced changes of eating: emotion-congruent modulation of eating and eating to regulate emotions.

A new animal model of binge eating: key synergistic role of past caloric restriction and stress

Dieting and stress are important in the etiology and maintenance of eating disorders, and dieting strongly predicts stress-induced overeating in humans. We hypothesized that caloric restriction and stress interact in a unique manner to promote binge eating. To test this hypothesis, a group of young female rats were cycled through a restriction period (4 days of 66% of control food intake) followed by 6 days of free feeding prior to being stressed by acute foot shock. After three of these cycles, the food intake of rats exposed only to restriction (R), or only to stress (S), did not differ from controls. However, R+S rats that were restricted and refed, despite normal body weight and food intake after free feeding, engaged in a powerful bout of hyperphagia when stressed (Experiment 1). The R + S effect was replicated in an older group of rats (Experiment 2). The hyperphagia was characteristically binge-like, it constituted a 40% selective increase in highly palatable (HP) food (P < .001) over a discrete period of time (within 24 h post-stress), and reflected feeding for reward (higher HP:chow ratio) over metabolic need as occurred after restriction (higher chow:HP ratio). Subsequent experiments revealed that binge eating did not occur if only chow was available (Experiment 3) or if restriction-refeeding (R-R) did not proximally precede stress (Experiment 4). Experiment 5 revealed that a history of R-R cycles followed by only one stress episode was sufficient to increase intake to 53% above controls as early as 2 h after stress (P < .001). This animal model of binge eating should facilitate investigations into the neurochemical changes induced by dieting and environmental stress to produce disordered eating and provide a preclinical tool to test preventive strategies and treatments more relevant to bulimia nervosa, multiple cases of binge eating disorder (BED) and binge-purge type anorexia nervosa.

Carbohydrate ingestion, blood glucose and mood

A series of studies have reported that a high carbohydrate meal, or diets high in carbohydrate, were associated with feeling less energetic. However, after a drink containing pure sugar most studies report no effect. Meals almost exclusively carbohydrate increase the availability of tryptophan and hence serotonin synthesis in the brain, however, a small amount of protein blocks this mechanism making it an uncommon response. In many individuals, poor mood stimulates the eating of palatable high carbohydrate/high fat foods that stimulate the release of endorphins. There is a tendency for those with lower blood glucose, when performing cognitively demanding tasks, to report poorer mood. In a range of situations an association between a tendency for blood glucose levels to fall rapidly, and irritability, has been found. Differences in the ability to control blood glucose levels influence the association between carbohydrate intake and mood. There is a need in future research to contrast the impact of carbohydrate on mood in those distinguished because of their pre-existing psychological and physiological functioning.

The effects of amygdala lesions on conditioned stimulus-potentiated eating in rats

Both control rats and rats with neurotoxic lesions of the amygdala central nucleus ate more food during presentations of a conditioned stimulus (CS) previously paired with food than during an unpaired CS. This potentiation occurred regardless of whether the food was presented in its usual place or in a different location. By contrast, rats with neurotoxic lesions of basolateral amygdala showed no evidence for conditioned potentiation of eating. These results are considered in the context of anatomical projections from these amygdalar areas to other brain regions involved in feeding, and the role of amygdala subregions in the acquisition of motivational value in conditioning.

Stress-induced relapse to drug seeking in the rat: role of the bed nucleus of the stria terminalis and amygdala

There is growing interest in the role that the bed nucleus of the stria terminalis (BNST) and central nucleus of the amygdala (CeA), components of the extended amygdala, play in drug addiction. Within the BNST and CeA, there is an extensive system of intrinsic, primarily GABAergic, interconnections known to synthesize a variety of neuropeptides, including corticotrophin-releasing factor (CRF). The actions of CRF at extrahypothalamic sites,including the BNST and CeA, have been implicated in stress responses and in the aversive effects of withdrawal from drugs of abuse. Most recently, we have shown a critical role for extrahypothalamic CRF in stress-induced reinstatement of drug seeking in rats. In attempting to determine which brain circuitry mediates the effect of stress on relapse and, more specifically, where in the brain CRF acts to initiate the behaviours involved in relapse, we focused on the BNST and CeA. In the present paper, we summarize studies we have conducted that explore the role of these brain sites in stress-induced relapse to heroin and cocaine seeking, and then consider how our findings can be understood within the more general context of what is known about the role of the BNST and CeA in stress-related and general approach behaviours, such as drug seeking.

Stress and food choice: a laboratory study

OBJECTIVE

This study investigated experimentally whether acute stress alters food choice during a meal. The study was designed to test claims of selective effects of stress on appetite for specific sensory and nutritional categories of food and interactions with eating attitudes.

METHODS

Sixty-eight healthy men and women volunteered for a study on "the effects of hunger on physiology, performance, and mood." Eating attitudes and food preferences were measured on entry to the study. The stressed group prepared a 4-minute speech, expecting it to be filmed and assessed after a midday meal, although in fact speeches were not performed. The ad libitum meal included sweet, salty, or bland high- and low-fat foods. The control group listened to a passage of neutral text before eating the meal. Blood pressure, heart rate, mood, and hunger were measured at baseline and after the 10-minute preparatory period, when appetite for 34 foods and food intake were recorded.

RESULTS

Increases in blood pressure and changes in mood confirmed the effectiveness of the stressor. Stress did not alter overall intake, nor intake of, or appetite for the six food categories. However, stressed emotional eaters ate more sweet high-fat foods and a more energy-dense meal than unstressed and nonemotional eaters. Dietary restraint did not significantly affect appetitive responses to stress.

CONCLUSIONS

Increased eating of sweet fatty foods by emotional eaters during stress, found here in a laboratory setting, may underlie the previously reported finding that dietary restraint or female gender predicts stress-induced eating. Stress may compromise the health of susceptible individuals through deleterious stress-related changes in food choice.

Stress-induced relapse to heroin and cocaine seeking in rats: a review

Studies in humans suggest that exposure to stress increases the probability of relapse to drug use, but until recently there has been no animal model to study the mechanisms that mediate this effect. We have developed a reinstatement procedure that allows us to study the effect of stress on relapse to drug seeking in rats. Using this procedure, we have shown that exposure to intermittent footshock stress reliably reinstates heroin and cocaine seeking after prolonged drug-free periods. In the present paper, we summarize results from several studies on stress-induced reinstatement of heroin and cocaine seeking in rats. We first assess the degree to which the phenomenon of stress-induced relapse generalizes to other stressors, to behaviors controlled by other drugs of abuse, and to behaviors controlled by non-drug reinforcers. We then review evidence from studies concerned with the neurotransmitters, the brain sites, and the neural systems involved in stress-induced reinstatement of drug seeking. Finally, we consider the mechanisms that might underlie stress-induced relapse to drug seeking and the possible implications of the findings for the treatment of relapse to drug use in humans.

Emotions and eating in everyday life

This field study assessed emotional states experienced in everyday life and examined the subjective motivation to eat associated with these emotional states. Twenty-three female subjects rated their momentary emotional state and motivation to eat on 6 consecutive days at 11:00a.m., 2:00p.m., 5:00p.m., 8:00p.m. and 11:00p.m. A cluster analysis of the resulting 634 emotion profiles revealed three types of emotional states characterized by the labels "Anger-dominance", "Tension/Fear" and "Relaxation/Joy". A fourth cluster showing generally low levels of emotions was labelled "Unemotional state". Most of the self-rated motivations to eat were increased during periods of negative emotions. During negative emotions a heightened tendency to cope with these emotions through eating and more intense bodily symptoms of hunger were also reported. No differences in motivations to eat were found between the two negative emotion clusters or between relaxation/joy and the unemotional state. Results indicate the presence of "emotionally instrumental eating" in a non-clinical population under real life conditions. Physiological correlates of negative emotional states may be involved in emotionally instrumental eating.

Food craving and food "addiction": a critical review of the evidence from a biopsychosocial perspective

Although certain commonalities exist between eating and drug use (mood effects, external cue-control of appetites, reinforcement, etc. ), it is argued that the vast majority of cases of (self-reported) food craving and food "addiction" should not be viewed as addictive behavior. An explanation is proposed that instead gives a prominent role to the psychological processes of ambivalence and attribution, operating together with normal mechanisms of appetite control, the hedonic effects of certain foods, and socially and culturally determined perceptions of appropriate intakes and uses of those foods. Ambivalence (e.g., "nice but naughty") about foods such as chocolate arises from the attitude that it is highly palatable but should be eaten with restraint. Attempts to restrict intake, however, cause the desire for chocolate to become more salient, an experience that is then labelled as a craving. This, together with a need to provide a reason for why resisting eating chocolate is difficult and sometimes fails, can, in turn, lead the individual to an explanation in terms of addiction (e.g., "chocoholism"). Moreishness ("causing a desire for more") occurs during, rather than preceding, an eating episode, and is experienced when the eater attempts to limit consumption before appetite for the food has been sated.

Stress, dietary restraint and food intake

OBJECTIVE

The purpose of this study was to examine the associations between work stress and nutritional status in relation to dietary restraint in a community sample of adults.

METHODS

The design included a cross-sectional and a longitudinal study element. Ninety staff members (58 women and 32 men) of a large department store were assessed on four occasions over a 6-month period with measures of diet, weight, and perceived stress. Work stress was indexed in terms of the hours of work over the past 7 days, which provided an objective indicator of demand.

RESULTS

Participants worked an average of 47 hours on the high-work-stress session compared with 32 hours on the low-work-stress session. The highest work-stress session was compared with the lowest work-stress session in the longitudinal analyses, and the moderating effects of gender and restrained eating were examined. High-workload periods were associated with higher energy and saturated fat and sugar intake. There was a significant moderating effect of restrained eating, with a hyperphagic response to work stress in restrained eaters, compared with no effect in unrestrained eaters.

CONCLUSION

The results indicate that the associations between restraint and stress-induced eating that have been observed in the laboratory extend to the real-life setting. They raise the possibility that restrained eaters are particularly vulnerable to adverse effects of stress on health, through influences on food intake.

Neurotransmitter system interactions revealed by drug-induced changes in motivated behavior

The present article reviews studies conducted either in collaboration with Jac Herberg, or in parallel with those studies that used consummatory behavior and responding for intracranial self-stimulation (ICSS) to investigate interactions between neurotransmitter systems. The studies reviewed include investigations of the role of dopamine in 8-OH-DPAT-induced feeding; the role of 5-HT3 receptors in the stimulant and depressant effects of nicotine on responding for ICSS; the interaction of D2 and 5-HT2 antagonists in sucrose consumption, and the differential contributions of alpha2-adrenoceptor and 5-HT2 antagonism to the rapid recovery of ICSS responding from depression produced by atypical neuroleptics. Further studies of the role of alpha2-adrenoceptor antagonism in the pattern of response decrements produced by neuroleptics on schedule-controlled responding for food confirm that the behavioral effects of monoamine interactions vary, depending on the specific receptor subtypes targeted and the behavioral paradigm employed. Consequently, the clinical relevance of findings will crucially depend on the choice of appropriate behavioral measures.

Eating habits and appetite control: a psychobiological perspective

An individual's eating behaviour is shaped by factors ranging from economic conditions and cultural practices to biological influences. The physiological system controlling appetite appears to be adapted to solving the problem of an unevenness of food supply across time, and is fairly permissive in its response to undereating and overeating. Consequently, when food is abundant, the diet is energy dense and energy expenditure is low, there is a strong tendency to become obese (i.e. obesity is better viewed as due to a 'toxic' environment than to faulty physiological control of appetite). Under such conditions the most common method of avoiding obesity is through the cognitive control of eating. However, dietary restraint and dieting are demanding tasks, and are associated with psychological costs, including significant impairment of cognitive performance. Restraint is also prone to disinhibition, with the result that it can sometimes undermine eating control, even leading to the development of highly disordered eating patterns. In part, these difficulties are due to the self-perpetuating nature of dietary habits: for example, hunger tends to be diminished during strict unbroken dieting, but increased in individuals having a highly variable eating pattern (such as occurs when eating is frequently disinhibited). These features of appetite control provide both barriers and opportunities for changing behaviour. Accordingly, there is a need for future research to focus on the psycho-social factors and the dieting practices predicting successful eating and weight control, with the objective of identifying the actual cognitive and behavioural strategies used by the many dieters and restrained eaters who are able to achieve weight loss and maintain long-term weight stability.