Stress-induced eating in restrained eaters may not be caused by stress or restraint

Stress mindset predicts psychophysiological responses to stress and eating behaviors and moderates the stress-eating relationship in women

Individuals tend to shift their preferences towards comfort foods following acute stressors, but do not ubiquitously increase the amount of food consumed. Many individuals overeat in response to stressors, yet others decrease or do not change their food intake. Individual differences in factors related to stress and eating, such as stress mindset (i.e., perceptions regarding the nature of stress), may explain this variability in stress-eating. To investigate, we conducted the present pre-registered study, where we investigated whether stress mindset, 1) predicted psychophysiological stress responses, 2) predicted snack intake post-stress, and 3) moderated the stress-eating relationship. Participants were 86 women (34 % non-White) between 18 and 22 years old, with a mean body mass index of 24 kg/m2, who completed two visits. Participants completed an assessment of stress mindset during a preliminary screening and, on a subsequent laboratory visit, underwent a stress mindset manipulation followed by an acute social stress task (i.e., TSST) and a snack food taste test. Greater stress-is-enhancing mindsets during screening predicted more adaptive stress responses (greater ratio of sympathetic markers to cortisol levels) and healthier post-stress eating behaviors. Furthermore, the moderation model (PROCESS model 1) was significant: greater post-stress negative affect was associated with more M&M intake only for women with greater stress-is-debilitating mindsets at screening, and greater heart rate was associated with less chip and veggie straw intake only for women with greater stress-is-enhancing mindsets at screening. Thus, stronger stress-is-enhancing mindsets may reduce the impact of psychophysiological stress responses on snack food intake for women. Replications in larger and more diverse samples may elucidate the mechanisms underlying the moderation and inform eating- and obesity-related treatments targeting stress mindset.

Eating behaviour characteristics and dietary intake among Japanese junior high school students: A cross-sectional study

BACKGROUND

Psychological characteristics of eating behaviour may be related to dietary habits.

AIM

We investigated the association between eating behaviour characteristics and nutrition and food intake adequacy in Japanese adolescents.

METHODS

This cross-sectional survey was conducted among 136 junior high school students (boys: 90, girls: 46) at a junior high school in Tokyo, Japan. Eating behaviour was categorised into three types (emotional, external, and restrained) using scores on the Japanese version of the Dutch Eating Behaviour Questionnaire. Dietary intake was assessed using a validated, brief self-administered diet history questionnaire. Inadequate nutrient intake was determined by counting the number of nutrients not meeting the dietary reference intake (DRI) for the Japanese population. The statistical analyses included Wilcoxon signed-rank tests, Spearman's rank correlation coefficient, and multiple regression analysis using JMP ver.14 (SAS Institute Inc., Cary, NC, USA). All reported p values are two-tailed, and p < 0.05 was regarded as statistically significant.

RESULTS

Multiple regression analysis showed that restrained eating score was inversely associated with the number of nutrients not meeting the DRI (β =  - 0.28; p = 0.0027) and with total weight of snack intake (β =  - 0.30; p = 0.0010). Neither emotional nor external eating was significantly associated with the number of nutrients not meeting the DRI and with total weight of snack intake.

CONCLUSIONS

These results suggest that adolescents with low restrained eating scores may have less self-control over their eating behaviour and may therefore have inadequate dietary intake.

Sex differences in the relationship between hepatic steatosis, mood and anxiety disorders

OBJECTIVE

To investigate the association between non-alcoholic fatty liver disease (NAFLD), alcoholic liver disease (ALD), mental symptoms (mood, anxiety disorders and distress) by sex.

METHODS

This a cross-sectional study performed in working-age adults from a Health Promotion Center (primary care) in São Paulo, Brazil. Self-reported mental symptoms from rating scales (21-item Beck Anxiety Inventory, Patient Health Questionnaire-9, and K6 distress scale) were evaluated by hepatic steatosis (NAFLD and ALD). Logistic regression models estimated the association between hepatic steatosis subtypes and mental symptoms by Odds ratios (OR) adjusted by confounders in the total sample and sex stratified.

RESULTS

Among 7241 participants (70.5% men, median age: 45 years), the frequency of steatosis was of 30.7% (25.1% NAFLD), being higher in men than women (70.5% vs. 29.5%, p < 0.0001), regardless of the steatosis subtype. Metabolic risk factors were similar in both subtypes of steatosis, but not mental symptoms. Overall, NAFLD was inversely associated with anxiety (OR = 0.75, 95%CI 0.63-0.90) and positively associated with depression (OR = 1.17, 95%CI 1.00-1.38). On the other hand, ALD was positively associated with anxiety (OR = 1.51; 95%CI 1.15-2.00). In sex-stratified analyses, only men presented an association of anxiety symptoms with NAFLD (OR = 0.73; 95%CI 0.60-0.89) and ALD (OR = 1.60; 95%CI 1.18-2.16).

CONCLUSIONS

The complex association between different types of steatosis (NAFLD and ALD), mood and anxiety disorders indicates the need for a deeper understanding of their common causal pathways.

Perceived Stress Is Directly Associated with Major Consumption of Sugar-Sweetened Beverages among Public University Students

Stress is a condition that has been related to the development of risk behaviors for health such as sugar-sweetened beverages (SSBs) consumption. The aim of this study was to examine the link between SSBs consumption and perceived stress level in university students. This was an observational, cross-sectional and single-time-point study where the subjects were recruited as a non-probabilistic sample of first-year university students. The students reported their SSBs consumption through a validated questionnaire, as well as their perceived stress level, evaluated through the Cohen scale. Comparisons were made between the means of all variables. Factorial analysis of variance was conducted to explore the effect of the variables’ interaction on the stress level. One-way analysis of variance was performed to assess differences between the sexes. Men consumed more SSBs (6101.17 ± 3772.50 mL/week) compared to women (4294.06 ± 3093.8 mL/week). However, women had higher scores of perceived stress and showed a strong association of stress with the SSBs consumption pattern (r and p-value). This study shows for the first time the association that exists between stress and SSBs consumption and indicates that it is related to sex in the young population.

Validity and reliability of the Dietary Rules Inventory (DRI)

BACKGROUND

Dietary rules are common in patients with eating disorders, and according to transdiagnostic cognitive behavioural theory for eating disorders, represent a key behaviour maintaining eating-disorder psychopathology. The aim of this study was to describe the design and validation of the Dietary Rules Inventory (DRI), a new self-report questionnaire that assesses dietary rules in patients with eating disorders.

METHODS

A transdiagnostic sample of 320 patients with eating disorders, as well as 95 patients with obesity and 122 healthy controls were recruited. Patients with eating disorders also completed the Dutch Eating Behaviour Questionnaire (DEBQ), the Eating Disorder Examination Questionnaire, the Brief Symptoms Inventory and the Clinical Impairment Assessment. Dietary rules were rated on a continuous Likert-type scale (0-4), rating how often (from never to always) they had been applied over the previous 28 days.

RESULTS

DRI scores were significantly higher in patients with eating disorders than in patients with obesity and healthy controls. Principal factor analysis identified that 55.8% of the variance was accounted for by four factors, namely 'what to eat', 'social eating', 'when and how much to eat' and 'caloric level'. Both global score and subscales demonstrated high internal and test-retest reliability. The DRI global score was significantly correlated with the DEBQ 'restrained eating' subscale, as well as eating-disorder and general psychopathology and clinical impairment scores, demonstrating good convergent validity.

CONCLUSIONS

These findings suggest that the DRI is a valid self-report questionnaire that may provide important clinical information regarding the dietary rules underlying dietary restraint in patients with eating disorders.

LEVEL OF EVIDENCE

V, descriptive study.

Hungry for colours? Attentional bias for food crucially depends on perceptual information

Attentional bias has been consistently investigated with both threatening and rewarding stimuli, such as food. Several studies demonstrated the presence of an attentional bias for high-calorie food cues compared to neutral (non-food) cues. Authors have interpreted this effect in the context of top-down processes (e.g. the food draws attention thanks to the experience we have with it). The aim of the present study is to test whether perceptual features (bottom-up processes) can modulate the attentional bias effect of food stimuli. Using a dot-probe task, we investigated the relevance of colours in the occurrence of the attentional bias. We compared two different categories of naturalistic food images (high-calorie versus low-calorie) both coloured (Exp. 1) and greyscale (Exp. 2). While we found the occurrence of the attentional bias with high-calorie food coloured images, we did not obtain any significant differences with greyscale images. In Experiments 3 and 4, we compared greyscale office items images, respectively, with greyscale high-calorie food images (Exp. 3) and greyscale low-calorie food images (Exp. 4). In both these last experiments, we did not find any attentional bias. Thus, taken together, our results show that colours convey crucial identity information that could orient our attention. We interpret these results as linked to the relevance of visual appearance in our experience of food.

When dessert comes close: The effects of anticipating indulgent consumption and dietary restraint on healthy food preference at restaurants

When dining in restaurants, diners often anticipate indulgent consumption, such as enjoying a dessert. This study examined the effects of anticipating such indulgence on preferences for healthy food among restrained and unrestrained eaters. Two experiments revealed that anticipating indulgent consumption reduced restrained eaters' preference for the immediate consumption of healthy food. Conversely, unrestrained eaters' expectation of indulgent consumption increased or did not change their preference for a healthy option. The interactive effect of indulgence anticipation and dietary restraint on healthy food preference held regardless of availability of nutrition information. The findings suggest that, despite increasing concern for healthy eating, restrained consumers ironically show a preference for unhealthy food options when anticipating a dessert consumption opportunity. The present study provides theoretical implications for consumption anticipation, sequential consumption, and dietary restraint, and practical implications for restaurateurs as well as for consumers, health professionals, and policymakers regarding healthy eating.

Stress-Induced Suppression of Food Intake in Overweight and Obese Adolescents

OBJECTIVE

Overweight adolescents exhibit greater cortisol reactivity in response to acute stress and are more likely to eat in response to emotional cues, which suggest an increased susceptibility to stress-induced eating. The purpose of this study was to examine the biological (cortisol and α-amylase reactivity) and behavioral (caloric intake) responses to an acute stressor in overweight adolescents.

METHODS

Fifty-one adolescents ages 14 to 19 years (47% female, 55% white; body mass index, 31.2 ± 0.8 kg/m) were exposed to the Trier Social Stress Test and a control condition on separate days. Immediately after each condition, participants were provided with snacks to eat at their leisure. Reactivity was assessed via salivary cortisol and α-amylase area under the curve (AUC), and adolescents were categorized as high or low reactors.

RESULTS

Cortisol AUC was higher during the stress condition (19.6 ± 0.2 μg/dl · min) compared with the control condition (11.4 ± 0.9 μg/dl · min, p < .001). α-Amylase AUC was not different during the stress condition (9999 ± 987 U/ml · min) compared with the control condition (8762 ± 865 U/ml · min, p = .145). Overall, adolescents consumed fewer calories during the stress condition (488 ± 51 kcal) compared with the control condition (637 ± 42 kcal, p = .007). High cortisol reactors decreased their calorie consumption from the control condition (716 ± 52 kcal) to the stress condition (457 ± 53 kcal, p = .001), whereas low cortisol reactors did not change their consumption (stress: 518 ± 87 kcal versus control: 561 ± 62 kcal, p = .574).

CONCLUSION

High cortisol reactivity in overweight adolescents resulted in decreased calorie consumption after an acute stressor. Further research is needed to understand the mechanisms underlying stress-induced suppression of food intake in overweight adolescents.

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.

Uncontrolled Eating during Pregnancy Predicts Fetal Growth: The Healthy Mom Zone Trial

Excess maternal weight gain during pregnancy elevates infants' risk for macrosomia and early-onset obesity. Eating behavior is also related to weight gain, but the relationship to fetal growth is unclear. We examined whether Healthy Mom Zone, an individually tailored, adaptive gestational weight gain intervention, and maternal eating behaviors affected fetal growth in pregnant women (n = 27) with a BMI > 24. At study enrollment (6-13 weeks gestation) and monthly thereafter, the Three-Factor Eating Questionnaire was completed. Ultrasounds were obtained monthly from 14-34 weeks gestation. Data were analyzed using multilevel modeling. Higher baseline levels of uncontrolled eating predicted faster rates of fetal growth in late gestation. Cognitive restraint was not associated with fetal growth, but moderated the effect of uncontrolled eating on fetal growth. Emotional eating was not associated with fetal growth. Among women with higher baseline levels of uncontrolled eating, fetuses of women in the control group grew faster and were larger in later gestation than those in the intervention group (study group × baseline uncontrolled eating × gestational week interaction, p = 0.03). This is one of the first intervention studies to use an individually tailored, adaptive design to manage weight gain in pregnancy to demonstrate potential effects on fetal growth. Results also suggest that it may be important to develop intervention content and strategies specific to pregnant women with high vs. low levels of disinhibited eating.

Food Cue Reactivity and the Brain-Heart Axis During Cognitive Stress Following Clinically Relevant Weight Loss

Successful weight loss maintainers are more vulnerable to stress induced eating. The aim of our study was to determine what effect an attention-demanding cognitive performance task had on brain-heart reactivity to visual food cues in women who maintained clinically relevant weight loss vs. women who had never weight cycled. A clinical weight loss group (CWL, n = 17) and a BMI-matched control group (CTL, n = 23) completed modified Stroop tasks that either included high calorie food pictures (Food Stroop) or excluded food cues (Office Stroop). ECG, breathing rate, and EEG were recorded. CWL participants: The Eating Restraint scores (Three Factor Eating Questionnaire) of the CWL participants correlated negatively with their heart rates recorded during the Food Stroop task (r = 0.62, p < 0.01). There was no such relationship in CTL participants. The P200 latencies in CWL participants evoked by the Stroop color-word cues at the C3 electrode were positively correlated to the log high frequency power in their cardiac spectrograms during the Food Stroop (r = 0.63, p < 0.02). There were no such relationships in the Office Stroop task nor in CTL participants. Combined Groups: Participants' heart rates were significantly lower (p < 0.05) and their RMSSD values and the log Total Power in their cardiac spectrograms were significantly greater during the Food Stroop vs. Office Stroop (p < 0.01, Bonferroni corrected). In conclusion Eating Restraint scores in CWL participants correlated with their Stroop heart rates, while the P200 latencies evoked by the Stroop cues correlated with the log high frequency power in their cardiac spectrograms (marker of cardiac vagal activation) during the Food Stroop task. This provides evidence that even 12 months after successful weight loss maintenance the cardiac ANS reactivity to food cues while completing a cognitive performance test was still different to that in individuals of normal weight who never weight cycled. Across all participants the cardiac ANS reactivity evoked by performing the Stroop task was lowered by food cues suggesting that the dampening effect of food cues on cardiac ANS reactivity may be one of the drivers of ‘stress induced' eating.

Features and Trajectories of Eating Behavior in Weight-Loss Maintenance: Results from the German Weight Control Registry

OBJECTIVE

Eating behaviors such as dietary restraint and disinhibition caused by emotional and external cues play a relevant role in weight-loss maintenance.

METHODS

Four hundred forty individuals with successful weight-loss maintenance included in the prospective German Weight Control Registry completed the Dutch Eating Behavior Questionnaire. Participants were categorized into the following two weight groups: stable weight trajectory (WS) (n = 280) and unstable weight trajectory (WUS) (n = 160) over the 2-year assessment period.

RESULTS

Those with successful weight-loss maintenance had significantly higher scores on the restrained and emotional eating subscales compared with a general population (GP) sample. At baseline, the WS individuals had lower restrained, emotional, and external eating scores compared with the WUS individuals. Over the 2-year follow-up period, the trajectories of the restraint scores decreased in both groups but stayed elevated compared with the GP sample. Scores of the emotional and external eating subscales remained stable in the WS group but increased in the WUS group.

CONCLUSIONS

A certain degree of restraint seems to be necessary for successful weight-loss maintenance; however, high emotional and external eating may counteract this effect, resulting in weight regain in the long run.

Stress and psychological constructs related to eating behavior are associated with anthropometry and body composition in young adults

BACKGROUND

The transition to college is associated with weight gain, but the relation between eating behavior indicators and anthropometric outcomes during this period remains unclear.

OBJECTIVE

We aimed to evaluate sex differences in stress, emotional eating, tendency to overeat, and restrained eating behavior, and determine whether the psycho-behavioral constructs assessed immediately prior to starting college are associated with anthropometry and adiposity at the start of college, and with first-semester weight gain.

METHODS

A prospective study administered the Three Factor Eating Questionnaire (TFEQ), Satter Eating Competence Inventory, and Perceived Stress Scale (PSS) to 264 participants one month before college. Body composition was assessed via dual energy X-ray absorptiometry (DXA) at the start of college, and anthropometry (weight, height, waist circumference [WC]) was collected at the beginning and end of the first semester. Ordinary least squares regression tested the cross-sectional association of baseline psychological and behavioral scales with baseline DXA and anthropometry, and the longitudinal association with change in anthropometry.

RESULTS

Among 264 participants, 91% (241) had baseline data, and 66% (173) completed follow-up. In sex-adjusted linear regression models, baseline TFEQ disinhibited and emotional (DE; EE) eating sub-scales were positively associated with baseline weight (P = 0.003; DE, P = 0.014; EE), body mass index (BMI, P = 0.002; DE, P = 0.001; EE), WC (P = 0.004; DE, P = 0.006; EE) and DXA fat mass index (P = 0.023; DE, P = 0.014; EE). Baseline PSS was positively associated with subsequent changes in weight and WC among males only (P_interaction = 0.0268 and 0.0017 for weight and WC, respectively).

CONCLUSION

College freshmen with questionnaire scores indicating a greater tendency to overeat in response to external cues and emotions tended to have greater weight, BMI, and WC at the start of college. Males with higher perceived stress at college entrance subsequently gained significantly more weight in the first semester, but no such relation was evident in females.

Relationship between work-family conflict and unhealthy eating: Does eating style matter?

There is increasing evidence to suggest that work-family conflict is implicated in poor eating patterns. Yet, the underlying mechanism remains unexplored. The objectives of the present study were to demonstrate the interplay between work-family conflict, eating style, and unhealthy eating, and to test whether body mass index (BMI) and its interactions further explicate the relationships. In this study, 586 Malaysian adults (normal weight n = 437, overweight n = 149) completed a questionnaire, which included demographic variables, work-family scales, eating style measures, namely, restrained, emotional or external eating and reported food intake. As hypothesized, results showed that family-to-work conflict (FWC), emotional eating and external eating were positively related to unhealthy food consumption. In addition, emotional eating was found to moderate the impact of FCW on eating. These findings are consistent with research that has revealed emotional eating can indeed increase the positive association between stress such as conflict and unhealthy food choices. However, we found no clear support for the interactive effects of BMI. Our research builds on the findings of existing research as it demonstrates the role of eating style in explaining the association between work-family conflict and unhealthy eating. This conclusion has potential implications for appropriate interventions and calls for the enhancement of various policies to tackle obesity and other health problems.

Differences in Knowledge, Stress, Sensation Seeking, and Locus of Control Linked to Dietary Adherence in Hemodialysis Patients

Patients with chronic kidney disease (CKD) often require regular hemodialysis (HD) to prolong life. However, between HD sessions, patients have to restrict their diets carefully to avoid excess accumulation of potassium, phosphate, sodium, and fluid, which their diseased kidneys can no longer regulate. Failure to adhere to their renal dietary regimes can be fatal; nevertheless, non-adherence is common, and yet little is known about the psychological variables that might predict this dietary behavior. Thus, this study aimed to assess whether dietary adherence might be affected by a variety of psychological factors including stress, personality, and health locus of control, as well as dietary knowledge, in chronic HD patients. Fifty-one patients (30 men; age range 25-85) who had undergone HD for at least 3 months and had been asked to restrict at least one of potassium, phosphate or fluid, were recruited from a hospital renal unit. Measures of adherence to each of potassium, phosphate, and fluid were derived from standard criteria for these physiological indices in renal patients. Knowledge of food/drink sources of these dietary factors, and their medical implications in relation to HD and CKD were assessed by a bespoke questionnaire. Psychological factors including stress, personality and health locus of control beliefs were measured by standardized questionnaires. Having to restrict a particular nutrient was associated with better knowledge of both food sources and medical complications for that nutrient; however, greater dietary knowledge was not linked to adherence, and knowledge of medical complications tended to be associated with poorer adherence to potassium and phosphate levels. Adherence to these two nutrient requirements was also associated with lower reported stress in the past week. Adherence was associated with differences in locus of control: these differences varied across indices although there was a tendency to believe in external loci. For potassium, phosphate, and fluid restriction, adherers were less likely to be sensation seekers but did not differ from non-adherers on impulsivity, anxiety sensitivity, or hopelessness. In conclusion, the links between dietary adherence and stress, locus of control and personality suggests that screening for such psychological factors may assist in managing adherence in HD patients.

Eating disorders need more experimental psychopathology

Eating disorders are severe and disabling mental disorders. The scientific study of eating disorders has expanded dramatically over the past few decades, and provided significant understanding of eating disorders and their treatments. Those significant advances notwithstanding, there is scant knowledge about key processes that are crucial to clinical improvement. The lack of understanding mechanisms that cause, maintain and change eating disorders, currently is the biggest problem facing the science of eating disorders. It hampers the development of really effective interventions that could be fine-tuned to target the mechanisms of change and, therefore, the development of more effective treatments. It is argued here that the science of eating disorders and eating disorder treatment could benefit tremendously from pure experimental studies into its mechanisms of change, that is, experimental psychopathology (EPP). To illustrate why eating disorders need more EPP research, some key symptoms - restriction of intake, binge eating and body overvaluation - will be discussed. EPP studies challenge some generally accepted views and offer a fresh new look at key symptoms. This will, consequently, better inform eating disorder treatments.

Effects of Anxiety on Caloric Intake and Satiety-Related Brain Activation in Women and Men

OBJECTIVE

To test the relationship of anxiety to caloric intake and food cue perception in women and men.

METHODS

Fifty-five twins (26 complete, 3 incomplete pairs; 51% women) underwent 2 functional magnetic resonance imaging (fMRI) scans (before and after a standardized meal) and then ate at an ad libitum buffet to objectively assess food intake. State and trait anxiety were assessed using the State-Trait Anxiety Inventory. During the fMRI scans, participants viewed blocks of fattening and nonfattening food images, and nonfood objects.

RESULTS

In women, higher trait anxiety was associated with a higher body mass index (BMI) (r = 0.40, p = .010). Trait anxiety was positively associated with kilocalories consumed at the buffet (r = 0.53, p = .005) and percent kilocalories consumed from fat (r = 0.30, p = .006), adjusted for BMI. In within-pair models, which control for shared familial and genetic factors, higher trait anxiety remained associated with kilocalories consumed at the buffet (p = .66, p = .014), but not with BMI. In men, higher state anxiety was related to macronutrient choices, but not to total caloric intake or BMI. FMRI results revealed that women with high trait anxiety did not suppress activation by fattening food cues across brain regions associated with satiety perception after eating a standardized meal (low anxiety, mean difference = -15.4, p < .001; high anxiety, mean difference = -1.53, p = .82, adjusted for BMI).

CONCLUSIONS

In women, trait anxiety may promote excess caloric consumption through altered perception of high-calorie environmental food cues, placing women with genetic predispositions toward weight gain at risk of obesity.

TRIAL REGISTRATION

Clinicaltrials.govidentifier:NCT02483663.

Catastrophizing and anxiety sensitivity mediate the relationship between persistent pain and emotional eating

Stress-induced or "emotional eating" contributes to increased caloric intake and weight gain, yet models examining psychosocial factors that promote and sustain this behavior are incomplete. There is a need to identify explicit, clinically-relevant mechanisms of emotional eating behavior. Pain is a common stressor associated with increased weight and, potentially, altered eating behaviors. The present study applies the Fear Avoidance Model (FAM) of pain to examine processes that may explain the relationship between pain and increased weight while also providing the opportunity to examine specific mechanisms that may encourage eating during a variety of stressors. Our aim is to better understand the impact of pain on eating behavior and the potential for the FAM to improve our understanding of the psychological mechanisms that promote eating during times of duress. A survey of 312 adults explored the link between pain experience and stress-induced eating, further examining the mediating effects of the psychological aspects of the FAM (e.g., anxiety sensitivity, catastrophizing, and pain-related fear). 24% of respondents reported persistent pain, and had significantly higher BMIs than their pain-free peers. All three FAM components were positively correlated with measures of emotional, external, and restrained eating. Anxiety sensitivity and catastrophizing significantly mediated the relationship between persistent pain and emotional eating behavior, while anxiety sensitivity alone mediated the relationship between persistent pain and external eating. Findings suggest pain may be associated with increased likelihood for emotional eating and that characteristics from FAM, in particular anxiety sensitivity and catastrophizing, may mediate the relationship between the presence of persistent pain and emotional eating behavior. Evidence-based treatments targeting anxiety sensitivity and catastrophizing could be useful to address emotional eating in individuals struggling with both weight and chronic pain.

Shared and unique mechanisms underlying binge eating disorder and addictive disorders

Scientific interest in "food addiction" is growing, but the topic remains controversial. One critique of "food addiction" is its high degree of phenotypic overlap with binge eating disorder (BED). In order to examine associations between problematic eating behaviors, such as binge eating and "food addiction," we propose the need to move past examining similarities and differences in symptomology. Instead, focusing on relevant mechanisms may more effectively determine whether "food addiction" contributes to disordered eating behavior for some individuals. This paper reviews the evidence for mechanisms that are shared (i.e., reward dysfunction, impulsivity) and unique for addiction (i.e., withdrawal, tolerance) and eating disorder (i.e., dietary restraint, shape/weight concern) frameworks. This review will provide a guiding framework to outline future areas of research needed to evaluate the validity of the "food addiction" model and to understand its potential contribution to disordered eating.

Perceived stress, unhealthy eating behaviors, and severe obesity in low-income women

Background

Stress has been associated with poor eating behaviors and diet quality, as well as high body mass index (BMI). Low-income women may be particularly vulnerable to stress and severe obesity. Yet it is unknown how stress increases the risk of severe obesity through disordered eating behaviors and poor diet quality or through mechanisms independent of diet.

Methods

We examined cross-sectional data from women (n = 101) with a child enrolled in the Special Supplemental Nutrition Program for Women, Infants, and Children in Cumberland County, North Carolina (spring 2012). We collected measured heights and weights to calculate BMI. Using structural equation modeling, we differentiated pathways from stress to weight status: (1) indirectly through eating behaviors (cognitive restraint, emotional eating, and uncontrolled eating) and diet quality, which we examined with the Healthy Eating Index 2010 and 24-h dietary recalls, and (2) directly through possible unmeasured risk factors independent of diet. The analysis controlled for race/ethnicity, income, age, whether the dietary recall day was typical, and whether the respondent completed one or two 24-h dietary recalls.

Results

Perceived stress was positively associated with uncontrolled eating (β = 0.38, p < 0.001) and emotional eating (β = 0.50, p < 0.001). However, higher stress was not associated with weight status through eating behaviors and diet quality. Independent of eating behaviors and diet quality, stress was positively associated with severe obesity (β = 0.26, p = 0.007).

Conclusions

Improving stress coping strategies for low-income women may improve eating behaviors and reduce severe obesity.

Electronic supplementary material

The online version of this article (doi:10.1186/s12937-015-0110-4) contains supplementary material, which is available to authorized users.

Stressful task increases drive for thinness and bulimia: a laboratory study

The scientific literature has suggested that stress undergirds the development of eating disorders (ED). Therefore, this study explored whether laboratory induced stress increases self-reported drive for thinness and bulimic symptoms measured via self-report. The relationship between control, perfectionism, stress, and cognition related to ED was examined using correlational methodology. Eighty-six participants completed an experimental task using a personal computer (PC). All individuals completed a battery of tests before and after the stressful task. Analyses showed a significant statistical increase in average scores on the drive for thinness and bulimia measured before and after a stressful task, and path analysis revealed two different cognitive models for the mechanism leading to drive for thinness and bulimia. These findings suggest that stress is an important factor in the development of the drive for thinness and bulimia.

Integrating fundamental concepts of obesity and eating disorders: implications for the obesity epidemic

Physiological mechanisms promote weight gain after famine. Because eating disorders, obesity, and dieting limit food intake, they are famine-like experiences. The development of the concept of meeting an ideal weight was the beginning of increasing obesity. Weight stigma, the perception of being fat, lack of understanding of normal growth and development, and increased concern about obesity on the part of health providers, parents, and caregivers have reinforced each other to promote dieting. Because weight suppression and disinhibition provoke long-term weight increase, dieting is a major factor producing the obesity epidemic. The integrated eating disorder-obesity theory included in this article emphasizes that, contrary to dieters, lifetime weight maintainers depend on physiological processes to control weight and experience minimal weight change.

Examining the associations between overeating, disinhibition, and hunger in a nonclinical sample of college women

BACKGROUND

Binge eating (BE) has long been identified as a correlate of overweight and obesity. However, less empirical attention has been given to overeating with and without loss of control (LOC) in nonclinical samples.

PURPOSE

The goal of the present study was to examine the association of (1) established correlates of BE, namely, weight and shape concerns, dietary restraint, and negative affect, and (2) three additional correlates, disinhibition, hunger, and interoceptive awareness (IA), to overeating in a nonclinical sample of college women.

METHOD

Female students (n = 1,447) aged 18 to 21 years recruited from colleges in three Canadian metropolitan areas completed self-report questionnaires in class to assess sociodemographic and anthropomorphic characteristics, overeating, LOC, dietary restraint, negative affect, weight and shape concerns, IA, disinhibition, and hunger.

RESULTS

The established correlates of BE were significant correlates of all types of overeating and explained 33 % of the variance. Disinhibition was the most strongly associated correlate of overeating.

CONCLUSIONS

Findings suggest that established correlates of BE are associated with other types of overeating such as objective overeating (OOE), as are disinhibition and hunger.

A twin study of differences in the response of plasma ghrelin to a milkshake preload in restrained eaters

BACKGROUND

Genetic, physiological, and psychological factors can affect food intake, but twin studies can distinguish inherited from environmental contributors. We examined the influence of attempted cognitive control of eating ("restrained eating") on levels of appetite-regulating hormones.

METHODS

Sixteen female, monozygotic twin pairs, discordant for Restraint Scale score (i.e., one twin a restrained eater with score>15 whereas the co-twin was unrestrained), were selected from the University of Washington Twin Registry. Serial plasma ghrelin concentrations were monitored during meals and a preload study paradigm involving intake of a milkshake followed by an ad libitum ice cream "taste test."

RESULTS

Body weight, body mass index, resting energy expenditure, and fasting leptin levels were very similar between restrained and unrestrained twins. In a preload study, twins ate similar amounts of ice cream shortly after drinking identical milkshakes (mean±SD; restrained 239±158 vs. unrestrained 228±132kcal; P=0.83). However, ghrelin concentrations during the preload study were significantly higher (P=0.03) in restrained twins than in their unrestrained co-twins. Regardless of restraint status, ghrelin levels prior to the preload study were prospectively and positively associated with ice cream intake (P=0.001).

CONCLUSIONS

Compared to their unrestrained co-twins, restrained twins had higher endogenous ghrelin levels during a preload study, but ate similar amounts. This finding is consistent with exertion of cognitive control relative to the state of physiologic appetite stimulation. Moreover, these findings in twins suggest that higher ghrelin levels result from restrained eating behavior and not from genetic predisposition.

Stress-related eating, obesity and associated behavioural traits in adolescents: a prospective population-based cohort study

BACKGROUND

Stress-related eating is associated with unhealthy eating and drinking habits and an increased risk of obesity among adults, but less is known about factors related to stress-driven eating behaviour among children and adolescents. We studied the prevalence of stress-related eating and its association with overweight, obesity, abdominal obesity, dietary and other health behaviours at the age of 16. Furthermore, we examined whether stress-related eating is predicted by early-life factors including birth size and maternal gestational health.

METHODS

The study population comprised 3598 girls and 3347 boys from the Northern Finland Birth Cohort 1986 (NFBC1986). Followed up since their antenatal period, adolescents underwent a clinical examination, and their stress-related eating behaviour, dietary habits and other health behaviours were assessed using a postal questionnaire. We examined associations using cross-tabulations followed by latent class analysis and logistic regression to profile the adolescents and explain the risk of obesity with behavioural traits.

RESULTS

Stress-related eating behaviour was more common among girls (43%) than among boys (15%). Compared with non-stress-driven eaters, stress-driven eaters had a higher prevalence of overweight, obesity and abdominal obesity. We found no significant associations between stress-eating and early-life factors. Among girls, tobacco use, shorter sleep, infrequent family meals and frequent consumption of chocolate, sweets, light sodas and alcohol were more prevalent among stress-driven eaters. Among boys, the proportions of those with frequent consumption of sausages, chocolate, sweets, hamburgers and pizza were greater among stress-driven eaters. For both genders, the proportions of those bingeing and using heavy exercise and strict diet for weight control were higher among stress-eaters. Besides a 'healthy lifestyle' cluster, latent class analysis revealed two other patterns ('adverse habits', 'unbalanced weight control') that significantly explained the risk of overweight among boys and girls.

CONCLUSIONS

Stress-related eating is highly prevalent among 16-year-old girls and is associated with obesity as well as adverse dietary and other health behaviours among both genders, but intrauterine conditions are seemingly uninvolved. In terms of obesity prevention and future health, adolescents who use eating as a passive way of coping could benefit from learning healthier strategies for stress and weight management.

A new biomarker of hedonic eating? A preliminary investigation of cortisol and nausea responses to acute opioid blockade

Overweight and obese individuals differ in their degree of hedonic eating. This may reflect adaptations in reward-related neural circuits, regulated in part by opioidergic activity. We examined an indirect, functional measure of central opioidergic activity by assessing cortisol and nausea responses to acute opioid blockade using the opioid antagonist naltrexone in overweight/obese women (mean BMI=31.1±4.8) prior to the start of a mindfulness-based intervention to reduce stress eating. In addition, we assessed indices of hedonic-related eating, including eating behaviors (binge eating, emotional eating, external eating, restraint) and intake of sweets/desserts and carbohydrates (Block Food Frequency); interoceptive awareness (which is associated with dysregulated eating behavior); and level of adiposity at baseline. Naltrexone-induced increases in cortisol were associated with greater emotional and restrained eating and lower interoceptive awareness. Naltrexone-induced nausea was associated with binge eating and higher adiposity. Furthermore, in a small exploratory analysis, naltrexone-induced nausea predicted treatment response to the mindfulness intervention, as participants with more severe nausea at baseline maintained weight whereas those with little or no nausea responses tended to gain weight. These preliminary data suggest that naltrexone-induced cortisol release and nausea may help identify individuals who have greater underlying food reward dependence, which leads to an excessive drive to eat. Future research is needed to confirm this finding and to test if these markers of opioidergic tone might help predict success in certain types of weight management programs.

Dieting in bulimia nervosa is associated with increased food restriction and psychopathology but decreased binge eating

The cognitive behavioral model of bulimia nervosa (BN) suggests that dieting is central to the maintenance of binge eating. However, correlational and experimental studies suggest that additional clarification is needed about the nature of this relationship. Dieting, weight, eating disorder psychopathology, and depression were assessed at admission among 166 patients with BN presenting for residential treatment. As in past research, a significant fraction (43%) of patients with BN reported not currently dieting. A comparison of weight loss dieters and non-dieters found greater food restriction and eating disorder psychopathology among weight loss dieters. However, dieters reported less frequent binge eating. There were no significant group differences in depression. Results suggest that 1) while many individuals with BN are attempting to restrict their food intake, the goal of losing weight fundamentally alters the effect of such restriction on binge eating, and 2) treatment may benefit from helping patients to establish a healthier approach to achieving long-term weight stability.

Stress management can facilitate weight loss in Greek overweight and obese women: a pilot study

BACKGROUND

Stress and negative emotions have been shown to be critical factors in inducing overeating as a form of maladaptive coping in obese people.

METHODS

The present study aimed to evaluate the efficacy of an 8-week stress management programme that includes progressive muscle relaxation (PMR) and diaphragmatic breathing on weight loss and eating behaviour in a sample of overweight and obese women who started a weight-loss programme. A total of 34 women with a mean (SD) body mass index of 38.17 (7.19) kg m(-) ² and mean (SD) age 47.35 (11.64) years were recruited from the outpatients Obesity Clinic of a public hospital in Athens. Participants were randomly assigned into a Stress Management (SM) and a control group. Anthropometric measurements were taken before and after the intervention, and the participants completed the following questionnaires: Dutch Eating Behaviour Questionnaire (DEBQ), Eating Attitudes Test (Eat-26), Health Locus of Control (HLC) and Perceived Stress Scale (PSS) before and after the intervention.

RESULTS

The findings indicated a significant improvement in weight loss in the SM group [4.44 (0.83) kg] after intervention compared to the control group [1.38 (0.78) kg] (P < 0.05). A higher restrained eating behaviour was observed in the SM group after intervention compared to the control group, although there was no significant difference in perceived stress levels.

CONCLUSIONS

The intervention group showed greater weight reduction, possibly because of the stress management programme, and a greater dietary restraint was demonstrated by them compared to the control group. It is likely that stress management could facilitate weight loss in obese women; however, more studies are needed to confirm this hypothesis.

Assessing the three types of dieting in the Three-Factor Model of dieting. The Dieting and Weight History Questionnaire

The construct of attempted eating restriction has been measured in a number of ways in recent years. The Three-Factor Model of Dieting suggests that dieting can be subdivided into three types: (1) frequency of past dieting and overeating (i.e., history of dieting), (2) current dieting to lose weight, and (3) weight suppression, or the difference between an individual's current weight and his or her highest previous weight. The purpose of this paper is to (1) describe the Dieting and Weight History Questionnaire (DWHQ), a measure that we have used for many years to assess these three dimensions of dieting; (2) provide some recent examples of published research on each type of dieting; (3) discuss some of the nuances of assessing these dieting types; and (4) suggest directions for future research.

Neural correlates to food-related behavior in normal-weight and overweight/obese participants

Two thirds of US adults are either obese or overweight and this rate is rising. Although the etiology of obesity is not yet fully understood, neuroimaging studies have demonstrated that the central nervous system has a principal role in regulating eating behavior. In this study, functional magnetic resonance imaging and survey data were evaluated for correlations between food-related problem behaviors and the neural regions underlying responses to visual food cues before and after eating in normal-weight individuals and overweight/obese individuals. In normal-weight individuals, activity in the left amygdala in response to high-calorie food vs. nonfood object cues was positively correlated with impaired satiety scores during fasting, suggesting that those with impaired satiety scores may have an abnormal anticipatory reward response. In overweight/obese individuals, activity in the dorsolateral prefrontal cortex (DLPFC) in response to low-calorie food cues was negatively correlated with impaired satiety during fasting, suggesting that individuals scoring lower in satiety impairment were more likely to activate the DLPFC inhibitory system. After eating, activity in both the putamen and the amygdala was positively correlated with impaired satiety scores among obese/overweight participants. While these individuals may volitionally suggest they are full, their functional response to food cues suggests food continues to be salient. These findings suggest brain regions involved in the evaluation of visual food cues may be mediated by satiety-related problems, dependent on calorie content, state of satiation, and body mass index.

Academic examination stress increases disordered eating symptomatology in female university students

BACKGROUND

It is well documented that stress and anxiety can affect eating behaviour and food intake in humans. The purpose of the current study was to explore the possible effect of academic examination stress on disordered eating attitudes, emotional eating, restraint eating, body image, anxiety levels and self-esteem in a group of female university students. The interrelationships of the above parameters were also examined.

METHODS

Sixty Greek female university students, 18-25 years old, have been recruited and completed, on two separate occasions: a) during an examination stress period, and b) during a control period, the following questionnaires: the Eating Attitudes Test (EAT-26), the Dutch Eating Behavior Questionnaire (DEBQ), the State-Trait Anxiety Inventory (STAI), the Rosenberg Self- Esteem Scale, the Body Image Pictorial Instrument Scale (COLLINS) and a specially designed General Background Questionnaire.

RESULTS

Subjects reported significantly higher levels of disordered eating attitudes (EAT-26, p=0.01), higher levels of anxiety (p=0.000) and lower levels of self-esteem (p=0.016) during the examination stress period compared to the control period. Disordered eating attitudes (EAT-26) were significantly positively correlated with emotional eating (p=0.04) and restrained eating (p=0.010) and negatively correlated with levels of self-esteem (p=0.05) and perceived desired body image (p=0.008) during the exam stress period. Finally, EAT-26 was significantly positively correlated with levels of anxiety in both study periods.

CONCLUSION

Academic examination stress seems to increase disordered eating symptomatology in female university students and is associated with lower levels of self-esteem, an important finding which warrants further investigation.

Restrained eating is related to accelerated reaction to high caloric foods and cardiac autonomic dysregulation

Cognitive bias to food-cues and cardiac autonomic dysregulation have both been related to disordered eating behavior in previous research. The present study investigated two possible measures of self-regulatory ability in restrained eaters: resistance to distractor interference and vagal-cardiac control. Young women (N=47) performed a flanker task involving high caloric food-cues or neutral pictures. Vagal-cardiac activity was calculated from baseline heart rate recordings at rest. Restrained eaters did not differ from unrestrained eaters in resistance to distractor interference. However, restrained eaters showed shorter reaction times to high-calorie food-cues as compared to neutral pictures than unrestrained eaters. This attentional bias was further related to low dieting success. Moreover, restrained eating was associated with low parasympathetic activation and sympathovagal imbalance, independent of current body mass. Both attentional bias and cardiac autonomic dysregulation were related to self-reported weight fluctuations. Results are discussed in terms of possible adverse consequences of weight cycling in young women and low self-regulatory ability in restrained eaters.

An examination of eating patterns in community women with bulimia nervosa and binge eating disorder

OBJECTIVE

To better understand the eating patterns of persons with eating disorders.

METHOD

This study investigated typical eating behavior (meal frequency and snacking) and atypical eating behavior among 311 community women with on-line questionnaires. Participants were classified with bulimia nervosa (BN; n =39), binge eating disorder (BED; n = 69), or controls (CON; n = 203).

RESULTS

In terms of typical eating behaviors, the BN group ate significantly fewer meals, particularly lunches, than the other two groups. Atypical eating, such as nibbling, eating double meals and nocturnal eating, was significantly more common in the eating disorder groups. More frequent breakfast consumption was associated with lower BMI in the BED and CON groups, and more frequent meal consumption was associated with less binge eating in the BED group only.

DISCUSSION

Our study revealed differences in typical and atypical eating patterns, and associations with weight and eating disorder behaviors among eating disorder and control groups.

Repetitive transcranial magnetic stimulation reduces cortisol concentrations in bulimic disorders

BACKGROUND

In people with bulimic eating disorders, exposure to high-calorie foods can result in increases in food craving, raised subjective stress and salivary cortisol concentrations. This cue-induced food craving can be reduced by repetitive transcranial magnetic stimulation (rTMS). We investigated whether rTMS has a similar effect on salivary cortisol concentrations, a measure of hypothalamic-pituitary-adrenal axis (HPAA) activity.

METHOD

We enrolled twenty-two female participants who took part in a double-blind randomized sham-controlled trial on the effects of rTMS on food craving. Per group, eleven participants were randomized to the real or sham rTMS condition. The intervention consisted of one session of high-frequency rTMS delivered to the left dorsolateral prefrontal cortex (DLPFC). Salivary cortisol concentrations were assessed at four time points throughout the 90-min trial. To investigate differences in post-rTMS concentrations between the real and sham rTMS groups, a random-effects model including the pre-rTMS cortisol concentrations as covariates was used.

RESULTS

Salivary cortisol concentrations following real rTMS were significantly lower compared with those following sham rTMS. In this sample, there was also a trend for real rTMS to reduce food craving more than sham rTMS.

CONCLUSIONS

These results suggest that rTMS applied to the left DLPFC alters HPAA activity in people with a bulimic disorder.

Response style and vulnerability to anger-induced eating in obese adults

Emotional eating appears to contribute to weight gain, but the characteristics that make one vulnerable to emotional eating remain unclear. The present study examined whether two negative affect response styles, rumination and distraction, influenced palatable food intake following an anger mood induction in normal weight and obese adults. We hypothesized that higher rumination and lower distraction would be associated with greater vulnerability to anger-induced eating, particularly among obese individuals. Sixty-one participants (74% female, mean age=34.6) underwent neutral and anger mood inductions in counterbalanced order. Directly following each mood induction, participants were provided with 2400 kcal of highly palatable snack foods in the context of a laboratory taste test. Results revealed that distraction influenced energy intake following the mood induction for obese but not normal weight individuals. Obese participants who reported greater use of distraction strategies consumed fewer calories than those reporting less use of distraction strategies. These findings were independent of subjective hunger levels, individual differences in mood responses and trait anger, and other factors. Rumination did not account for changes in energy intake among obese or normal weight participants. Among obese individuals, the tendency to utilize fewer negative affect distraction strategies appears to be associated with vulnerability to eating in response to anger. Future research should determine whether coping skills training can reduce emotional eating tendencies.

The association of restrained eating with weight change over time in a community-based sample of twins

We investigated the association of restrained eating with BMI and weight gain while controlling for the influence of genes and shared environment. Participants were 1,587 twins enrolled in the University of Washington Twin Registry (UWTR). Restrained eating was assessed by the Herman and Polivy Restraint Scale. Height and weight were self-reported on two occasions. Analyses used generalized estimating equations or multiple linear regression techniques. Restraint Scale scores were positively associated with both BMI (adjusted beta = 0.39 kg/m(2); 95% confidence interval (CI) = 0.34-0.44; P < 0.001) and weight gain (adjusted beta = 0.33 pounds; 95% CI = 0.17-0.49; P < 0.001). High Restraint Scale scorers had an adjusted mean BMI of 27.9 kg/m(2) (95% CI = 27.4-28.4) as compared to intermediate (mean = 25.5 kg/m(2); 95% CI = 25.2-25.8) and low scorers (mean = 23.0 kg/m(2); 95% CI = 22.7-23.3). In within-pair analyses among 598 same-sex twin pairs, the adjusted association between Restraint Scale scores and BMI persisted even when genetic and shared environmental factors were controlled for (adjusted beta = 0.18; 95% CI = 0.12-0.24; P < 0.001), as did the association with weight gain (adjusted beta = 0.37; 95% CI = 0.13-0.61; P = 0.003). In stratified analyses, dizygotic (DZ) twins differed more in BMI for a given difference in the Restraint Scale score than monozygotic (MZ) twins, for whom genetics are 100% controlled (adjusted beta = 0.32; 95% CI = 0.20-0.44 vs. adjusted beta = 0.10; 95% CI = 0.04-0.16; P = 0.001 for test of interaction). These data demonstrate that observed relationships between BMI, weight gain, and restrained eating, as assessed by the Restraint Scale, have a strong environmental influence and are not solely due to shared genetic factors.

Weight suppression predicts weight change over 5 years in bulimia nervosa

Recent studies suggest that weight suppression (WS), defined as the discrepancy between current and highest past weight, predicts short-term weight gain in bulimia nervosa (BN) during treatment. The current study was designed to build on this preliminary work by examining the relation between WS and long-term weight change in BN. Treatment-seeking women (N=97) with DSM-IV BN participated in a naturalistic longitudinal follow-up study of eating disorders. At intake, height and weight were measured and highest past weight was assessed. Self-reported weights were collected every 6 months for 5 years. Hierarchical Linear Modeling (HLM) estimated growth curves for weight change over time. Significant inter-person variability was detected for intercepts and slopes (P<0.001) so both were treated as random effects. Participants' weights increased over the study course, moderated by baseline WS (P<0.001), such that higher WS predicted more rapid weight gain. Weight change was not associated with entry weight, height, or highest-ever weight, suggesting that WS per se predicted weight change. These findings complement previous short-term studies in BN by demonstrating that WS predicts weight gain over 5 years. Because weight gain could spur radical dieting that maintains BN, these results have important treatment implications.

Genetic and environmental influences on restrained eating behavior

OBJECTIVE

We examined the relative contributions of genetic and environmental influences to restrained eating.

METHOD

Restrained eating was assessed by the Restraint Scale in a survey mailed to all twins enrolled in the University of Washington Twin Registry. We used structural equation modeling to estimate genetic and nongenetic contributions to restrained eating.

RESULTS

1,196 monozygotic (MZ), 456 same-sex dizygotic (DZ) twins, and 447 opposite-sex twins were included in analyses. Restraint Scale scores were more closely correlated in MZ twins (r(male) = .55, r(female) = .55) than in same-sex DZ twins (r(male) = .31, r(female) = .19). Based on structural equation modeling, the estimated heritability for restrained eating, adjusted for body mass index (BMI) and sex, was 43% (95% confidence interval 35-50%). There was little evidence for common environmental effects.

DISCUSSION

These results indicate an inherited component to restrained eating. Genes could influence restrained eating directly or through inherited mediators such as personality factors or tendencies to gain weight.

Dieting, restraint, and disinhibition predict women's weight change over 6 y

BACKGROUND

Although disinhibited eating is positively associated with higher weight in women, it is not known whether restrained eating and dieting moderate the influence of disinhibited eating on weight change.

OBJECTIVE

The objective was to investigate over 6 y the interactive effects of restrained and disinhibited eating and self-reported dieting to lose weight as predictors of weight gain in women.

DESIGN

Data were collected from non-Hispanic white women (n = 163) every 2 y. Height and weight were measured in triplicate. Dietary restraint and disinhibition were assessed by using the Eating Inventory. Participants were also asked if they were "currently dieting to lose weight." Multilevel modeling was used to examine change in weight as a function of time-invariant and time-varying predictors, including dietary restraint, dietary disinhibition, and self-reported dieting.

RESULTS

After covariates were adjusted for, growth curve models showed that within-person increases in restraint over time were associated with concurrent decreases in weight and that higher levels of restraint moderated the positive association between dietary disinhibition and weight. Women who reported dieting at study entry were heavier at study entry and gained more weight over time than did nondieters. Finally, a significant interaction between restraint, disinhibition, and dieting showed that restraint moderated the effect of disinhibition on weight differently in nondieters than in dieters.

CONCLUSIONS

Increasing levels of dietary restraint may be beneficial in moderating weight by attenuating the positive association between disinhibition and weight in dieting women. An understanding of weight and weight change requires examination of the interactive effects of restraint, disinhibition, and dieting.

Neural correlates of individual differences related to appetite

Using neuroimaging technologies to compare normal weight and obese individuals can reveal much about the pathophysiological state of obesity but such comparisons tell us little about what makes some normal weight individuals susceptible to obesity or about important individual differences amongst obese individuals. The current review therefore reviews neuroimaging research on individual difference measures that can illuminate these important topics. After introducing three neuropsychological models of the nature of motivation to approach rewarding stimuli, neuroimaging research on measures of impulsivity, craving, binge eating, restrained eating and disinhibited eating is reviewed. Although neuroimaging research on individual differences measures of brain activity related to appetite is in its infancy, existing studies suggest that such research could enrich the understanding, prevention and treatment of disordered eating and obesity.

Pregravid weight is associated with prior dietary restraint and psychosocial factors during pregnancy

The objective of this study was to investigate the association of pregravid weight status, previous dietary restraint, and psychosocial factors during pregnancy. We used data from the Pregnancy, Infection, and Nutrition study, which recruited 2,006 women at prenatal clinics before 20 weeks' gestation who were >16 years and English speaking. Institute of Medicine BMI cut points of underweight (<19.8), normal weight (19.8-26.0), overweight (>26.0-29.0), obese (>29.0-34.9), and an additional category extremely obese (> or =35.0), were used to categorize weight status. Eight psychosocial measures and dietary restraint were assessed with regard to BMI; perceived stress, trait anxiety, depressive symptoms, internal locus of control (LOC), chance LOC, powerful others LOC, self-esteem, and mastery. Linear regression was used to estimate associations, controlling for potential confounders. A significant trend was found between increasing pregravid weight categories and increasing scores for perceived stress, trait anxiety, depressive symptoms, powerful others LOC and dietary restraint, and decreasing scores for self-esteem and mastery. In adjusted models, pregravid obesity was independently associated with perceived stress, trait anxiety, and depressive symptoms. Extreme obesity was independently associated with all measures except internal LOC. A strong linear association was found between increasing weight categories and dietary restraint. In conclusion, as pregravid weight increased, pregnant women were at greater risk of reporting higher scores on negative psychosocial state and dietary restraints, and reporting lower score on positive personal dispositions.

Consummatory, anxiety-related and metabolic adaptations in female rats with alternating access to preferred food

Avoidance of and relapse to palatable foods is a qualitative aspect of dieting, a putative risk factor for eating disorders or obesity. The present studies tested the hypotheses that rats with alternating access to highly preferred foods would show: (1) hypophagia, a function of the relative hedonic value of the underaccepted diet, (2) increased anxiety-like behavior and psychomotor arousal when preferred diet was unavailable, (3) obesity-like changes, and (4) stable individual differences in diet-switch-induced hypophagia. Preferences among three high-carbohydrate diets were determined in female Wistar rats (n=16). Adolescent rats (n=162) received the following weekly diet schedules: (1) continuous regular chow (7 days/week), (2) chow (5 days/week) followed by a more preferred diet (2 days/week), or (3) chow (5 days/week) followed by a less preferred chow (2 days/week). Some animals were yoke-restricted (75% calories) when provided chow to increase its rewarding properties. Diurnal locomotor activity was measured in a familiar environment, and anxiety-like behavior was assessed in the elevated plus-maze and defensive withdrawal tests. Rats withdrawn from the preferred diet showed hypophagia, anxiogenic-like behavior, increased locomotion, and weight loss. Chow hypophagia was progressive, individual-specific in magnitude, (partly) non-homeostatic in nature, and blunted by previous chow restriction. Despite eating less, rats cycled with the preferred diet became heavier, fatter, and diurnally less active, with greater feed efficiency and proinflammatory adipokine levels than chow controls. The present diet cycling procedure may model consummatory, anxiety-related, and metabolic effects of qualitative dieting in humans.

Mood, Weight, and Physical Activity Among Obese Individuals Enrolled In a Long-term Weight-loss Program: Trajectories and Associations with Gender

OBJECTIVE: To examine the trajectories of mood, weight and physical activity, and associations between mood, weight, and gender, among 213 obese individuals. METHODS: Prospective, longitudinal design. Assessments at baseline and 6, 12, and 18 months of Profile of Mood States, Paffenbarger Physical Activity Questionnaire, and weight. RESULTS: Total mood disturbance decreased from baseline to 6 months, with no change thereafter. Weight decreased from baseline to 6 to 12 months, and increased from 12 to 18 months. Physical activity increased from baseline to 6 months, and 12 to 18 months. Increased physical activity predicted greater vigor and less fatigue over time. Females high in distress at 6 months lost less weight than females low in distress and at 18 months gained more weight than those low in distress. There were no such associations among males. CONCLUSION: The trajectories of mood, weight and physical activity were synchronous only in the short-term. Distress monitoring, targeted to females who relapse, may be warranted.

Dietary restraint and gestational weight gain

OBJECTIVE

To determine whether a history of preconceptional dieting and restrained eating was related to higher weight gains in pregnancy.

DESIGN

Dieting practices were assessed among a prospective cohort of pregnant women using the Revised Restraint Scale. Women were classified on three separate subscales as restrained eaters, dieters, and weight cyclers.

SUBJECTS

Participants included 1,223 women in the Pregnancy, Infection, and Nutrition Study.

MAIN OUTCOME MEASURES

Total gestational weight gain and adequacy of weight gain (ratio of observed/expected weight gain based on Institute of Medicine recommendations).

STATISTICAL ANALYSES PERFORMED

Multiple linear regression was used to model the two weight-gain outcomes, while controlling for potential confounders including physical activity and weight-gain attitudes.

RESULTS

There was a positive association between each subscale and total weight gain, as well as adequacy of weight gain. Women classified as cyclers gained an average of 2 kg more than noncyclers and showed higher observed/expected ratios by 0.2 units. Among restrained eaters and dieters, there was a differential effect by body mass index. With the exception of underweight women, all other weight status women with a history of dieting or restrained eating gained more weight during pregnancy and had higher adequacy of weight gain ratios. In contrast, underweight women with a history of restrained eating behaviors gained less weight compared to underweight women without those behaviors.

CONCLUSIONS

Restrained eating behaviors were associated with weight gains above the Institute of Medicine's recommendations for normal, overweight, and obese women, and weight gains below the recommendations for underweight women. Excessive gestational weight gain is of concern because of its association with postpartum weight retention. The dietary restraint tool is useful for identifying women who would benefit from nutritional counseling prior to or during pregnancy with regard to achieving targeted weight-gain recommendations.