Research supports both concurrent and prospective associations between peer behaviors and disordered eating levels in late adolescent and young adult men and women. However, no study has examined peer influence after a follow-up duration over which peer groups change dramatically. This study examined how college roommates’ dieting predicted disordered eating levels in women (n=566) and men (n=233) at 10-year follow-up. For women, college roommate dieting significantly predicted Drive for Thinness, Bulimia scores, and purging at 10-year follow-up. Findings highlight the potential for school-based, peer-led interventions to have long-term benefits in women.
peers; longitudinal; disordered eating
Studies suggest that within-person changes in estrogen and progesterone predict changes in binge eating across the menstrual cycle. However, samples have been extremely small (maximum N = 9), and analyses have not examined the interactive effects of hormones that are critical for changes in food intake in animals. The aims of the current study were to examine ovarian hormone interactions in the prediction of within-subject changes in emotional eating in the largest sample of women to date (N = 196). Participants provided daily ratings of emotional eating and saliva samples for hormone measurement for 45 consecutive days. Results confirmed that changes in ovarian hormones predict changes in emotional eating across the menstrual cycle, with a significant estradiol x progesterone interaction. Emotional eating scores were highest during the mid-luteal phase, when progesterone peaks and estradiol demonstrates a secondary peak. Findings extend previous work by highlighting significant interactions between estrogen and progesterone that explain mid-luteal increases in emotional eating. Future work should explore mechanisms (e.g., gene-hormone interactions) that contribute to both within- and between-subject differences in emotional eating.
Excessive diet soda intake is common in eating disorders. The present study examined factors contributing to excessive intake in a sample of individuals with lifetime eating disorders based on proposed DSM-5 criteria (n=240) and non-eating disorder controls (n=157). Individuals with eating disorders, particularly bulimia nervosa, consumed more diet soda than controls. Eating disorder symptoms that reflect increased appetitive drive or increased weight concerns were associated with increased diet soda intake. Increased weight concerns were associated with increased diet soda intake when levels of appetitive drive were high, but not when they were low. Results highlight the importance of monitoring diet soda intake in individuals with eating disorders and may have implications for the maintenance of dysregulated taste reward processing in BN.
Current research on the etiology of thin-ideal internalization focuses on psychosocial influences (e.g., media exposure). The possibility that genetic influences also account for variance in thin-ideal internalization has never been directly examined. This study used a twin design to estimate genetic effects on thin-ideal internalization and examine if environmental influences are primarily shared or nonshared in origin.
Participants were 343 post-pubertal female twins (ages 12–22; M=17.61) from the Michigan State University Twin Registry. Thin-ideal internalization was assessed using the Sociocultural Attitudes toward Appearance Questionniare-3.
Twin modeling suggested significant additive genetic and nonshared environmental influences on thin-ideal internalization. Shared environmental influences were small and non-significant.
Although prior research focused on psychosocial factors, genetic influences on thin-ideal internalization were significant and moderate in magnitude. Research is needed to investigate possible interplay between genetic and nonshared environmental factors in the development of thin-ideal internalization.
Thin-ideal; internalization; body image; disordered eating; twin study; heritability; Tripartite Model
We varied two defining features of Purging Disorder (PD): breadth of “purging” behaviors (purging only [narrow] vs. purging and nonpurging [broad]) and minimum behavioral frequency (once vs. twice per week) to examine their impact on syndrome validity.
Survey data from 1736 women and 755 men were used for analyses.
PD point prevalence was higher in women versus men, and prevalence was lowest for the narrow definition requiring purging twice per week. The narrow definition was associated with significant psychosocial impairment and increased effect sizes in validation analyses. Changing minimum behavioral frequencies did not impact associations with external validators.
A broad definition of PD that included any compensatory behavior reduced distinctions between PD and normality. Reducing minimum frequency to once per week did not reduce homogeneity or evidence of syndrome severity. Purging once per week may represent the optimal starting point in defining the central behavioral feature of PD.
purging disorder; EDNOS; classification; diagnostic validity; epidemiology
Conflicting results have emerged regarding the prognostic significance of weight suppression for maintenance of bulimic symptoms. This study examined whether the magnitude of weight suppression would predict bulimic syndrome maintenance and onset in college-based samples of men (n=369) and women (n=968) at 10-year follow-up. Data come from a longitudinal study of body weight and disordered eating with high retention (80%). Among those with a bulimic syndrome at baseline, greater weight suppression significantly predicted maintenance of the syndrome, and, among those without a bulimic syndrome at baseline, greater weight suppression predicted onset of a bulimic syndrome at 10-year follow-up in multivariate models that included baseline body mass index, diet frequency, and weight perception. Future research should address mechanisms that could account for the effects of weight suppression over a long duration of follow-up.
Bulimia; weight suppression; longitudinal; maintenance factor; risk factor
Converging evidence suggests a role for the anterior cingulate cortex (ACC) in the pathophysiology of anorexia nervosa (AN). This study sought to determine whether ACC volume was affected by starvation in active AN and, if so, whether this had any clinical significance.
Eighteen patients with active AN and age- and gender-matched normal controls underwent magnetic resonance imaging (MRI). Sixteen patients (89%) with AN had intelligence quotients (IQ) testing at intake, 14 (78%) had repeat MRIs after weight normalization, and 10 (56%) had outcome data at 1-year post-hospitalization.
Right dorsal ACC volume was significantly reduced in active AN patients versus controls and was correlated with lower performance IQ. While ACC normalization occurred with weight restoration, smaller change in right dorsal ACC volume prospectively predicted relapse after treatment.
Reduced right dorsal ACC volume during active AN relates to deficits in perceptual organization and conceptual reasoning. The degree of right dorsal ACC normalization during treatment is related to outcome.
dorsal anterior cingulate; ACC; anorexia nervosa; AN; starvation; weight restoration; cognitive function; performance IQ; MRI
We examined changes in drive for thinness, body dissatisfaction, and dietary restraint across the menstrual cycle and associations between these symptoms and ovarian hormones in two independent samples of women (N = 10 and 8 women, respectively) drawn from the community.
Daily self-report measures of disordered eating and negative affect were completed for 35–65 days. Daily saliva samples were assayed for estradiol and progesterone in Study 2 only.
Levels of body dissatisfaction and drive for thinness were highest during the mid-luteal/pre-menstrual phases in both studies and were negatively associated with estradiol, and positively associated with progesterone. By contrast, dietary restraint showed less variation across the menstrual cycle and weaker associations with ovarian hormones.
Differential associations between ovarian hormones and specific disordered eating symptoms point to distinct etiological processes within the broader construct of disordered eating.
estradiol; progesterone; ovarian hormones; menstrual cycle; eating disorders; disordered eating; drive for thinness; body dissatisfaction; dietary restraint
Previous research has found concurrent and prospective associations between negative mood and body dissatisfaction; however, only experimental research can establish causal relationships. This study utilized an experimental design to examine the influence of negative mood on body dissatisfaction. Undergraduate women were randomly assigned to an experimental or control condition. Participants in the experimental condition (n = 21) completed a negative mood induction procedure. Participants in the control condition (n = 24) completed a neutral mood procedure. All participants completed visual analogue scales regarding their mood and satisfaction with weight and shape before and after each manipulation. Body dissatisfaction increased following the procedure for experimental but not control participants, suggesting that negative mood caused increased body dissatisfaction. In cultures that idealize thinness, body dissatisfaction may arise from funneling general feelings of dysphoria into more concrete and culturally meaningful negative feelings about the body.
body image; experiment; negative affect; undergraduate women
Personality traits are known to be associated with a host of important life outcomes, including interpersonal dysfunction. The interpersonal circumplex offers a comprehensive system for articulating the kinds of interpersonal problems associated with personality traits. In the current study, traits as measured by the Multidimensional Personality Questionnaire (MPQ) in a sample of 124 young women were correlated with interpersonal dysfunction as measured by the Inventory of Interpersonal Problems-Circumplex. Results suggest that MPQ traits vary in their associations with interpersonal distress and in their coverage of specific kinds of interpersonal difficulties among women undergoing the transition to adulthood.
Binge eating has been associated with increased hunger, suggesting a role for impaired appetite regulation. Ecological momentary assessment (EMA) is ideally suited to examine whether hunger is a precipitant of binge eating but results from such studies have not been systematically reviewed. This study provides a meta-analysis of EMA studies that have examined hunger as an antecedent of binge eating.
Electronic database and manual searches produced seven EMA studies with N=180 participants. Meta-analyses were conducted to compare: 1) pre-binge eating hunger to average ratings of hunger, and 2) pre-binge eating hunger to hunger before regular eating.
Across studies, hunger was significantly greater prior to binge eating compared to average hunger ratings, but was significantly lower prior to binge eating compared to before other eating episodes.
Excessive hunger does not appear to be a precipitant of binge eating because higher levels of hunger are observed before regular eating episodes. However, lower hunger prior to food consumption may contribute to the experience of a particular eating episode as a binge.
binge eating; ecological momentary assessment; hunger
Elevated serum amylase levels in bulimia nervosa (BN), associated with increased salivary gland size and self-induced vomiting in some patients, provide a possible marker of symptom severity. The goal of this study was to assess whether serum hyperamylasemia in BN is more closely associated with binge eating episodes involving consumption of large amounts of food or with purging behavior.
Participants included women with BN (n=26); women with “purging disorder” (PD), a subtype of EDNOS characterized by recurrent purging in the absence of objectively large binge eating episodes (n=14); and healthy non-eating disorder female controls (n=32). There were no significant differences in age or body mass index (BMI) across groups. The clinical groups reported similar frequency of self-induced vomiting behavior and were free of psychotropic medications. Serum samples were obtained after overnight fast and were assayed for alpha-amylase by enzymatic method.
Serum amylase levels were significantly elevated in BN (60.7 ± 25.4 international units [IU]/liter, mean ± sd) in comparison to PD (44.7 ± 17.1 IU/L, p < 02) and to Controls (49.3 ± 15.8, p < .05).
These findings provide evidence to suggest that it is recurrent binge eating involving large amounts of food, rather than self-induced vomiting, which contributes to elevated serum amylase values in BN.
bulimia nervosa; purging disorder; self-induced vomiting; binge eating; serum amylase; hyperamylasemia
The affect regulation model of binge eating, which posits that patients binge eat to reduce negative affect (NA), has received support from cross-sectional and laboratory-based studies. Ecological momentary assessment (EMA) involves momentary ratings and repeated assessments over time and is ideally suited to identify temporal antecedents and consequences of binge eating. This meta-analytic review includes EMA studies of affect and binge eating. Electronic database and manual searches produced 36 EMA studies with N = 968 participants (89% Caucasian women). Meta-analyses examined changes in affect before and after binge eating using within-subjects standardized mean gain effect sizes (ES). Results supported greater NA preceding binge eating relative to average affect (ES = .63) and affect before regular eating (ES = .68). However, NA increased further following binge episodes (ES = .50). Preliminary findings suggested that NA decreased following purging in Bulimia Nervosa (ES = −.46). Moderators included diagnosis (with significantly greater elevations of NA prior to bingeing in Binge Eating Disorder compared to Bulimia Nervosa) and binge definition (with significantly smaller elevations of NA before binge versus regular eating episodes for the DSM definition compared to lay definitions of binge eating). Overall, results fail to support the affect regulation model of binge eating and challenge reductions in NA as a maintenance factor for binge eating. However, limitations of this literature include unidimensional analyses of NA and inadequate examination of affect during binge eating as binge eating may regulate only specific facets of affect or may reduce NA only during the episode.
binge eating; ecological momentary assessment; negative affect; bulimia nervosa
Ovarian hormones are associated with binge eating in women, however findings are limited by the lack of experimental control inherent in human studies. Animal research that manipulates ovarian hormone status and examines individual differences in extreme binge eating proneness are needed to model clinical phenotypes in humans and to confirm causal effects. The purpose of this study was to examine the effects of adult ovariectomy on overall binge eating risk and extreme binge eating phenotypes using the binge eating resistant (BER)/ binge eating prone (BEP) rat model. We predicted that palatable food consumption would significantly increase after ovariectomy in all rats because ovarian hormones generally suppress food intake. If differences in responsiveness to ovarian hormones underlie BER/BEP phenotypes, then differences in binge eating between BER and BEP rats would be eliminated or diminished after ovariectomy. Changes in palatable food (PF) intake were compared in BER and BEP rats before and after ovariectomy in two samples of adult females. Findings were highly similar in the two samples. PF intake increased significantly following ovariectomy in all rats. However, BEP rats consistently consumed larger amounts of PF than BER rats, both before and after ovariectomy. The consistency of findings across two samples of rats provides strong support for activational effects of ovarian hormones on binge eating. However, the immunity of extreme binge eating phenotypes to ovarian hormone ablation suggests that other, earlier mechanisms (e.g., organizational hormone effects or hormone-independent effects) determine the expression of binge eating phenotypes.
binge eating; bulimia nervosa; ovariectomy; animal models; ovarian hormones
Eating disorders are a significant source of psychiatric morbidity in young women and demonstrate high comorbidity with mood, anxiety, and substance use disorders. Thus, clinicians may encounter eating disorders in the context of treating other conditions. This review summarizes the efficacy of current and emerging treatments for anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED). Treatment trials were identified using electronic and manual searches and by reviewing abstracts from conference proceedings. Family based therapy has demonstrated superiority for adolescents with AN but no treatment has established superiority for adults. For BN, both 60 mg fluoxetine and cognitive behavioral therapy (CBT) have well-established efficacy. For BED, selective serotonin reuptake inhibitors, CBT, and interpersonal psychotherapy have demonstrated efficacy. Emerging directions for AN include investigation of the antipsychotic olanzapine and several novel psychosocial treatments. Future directions for BN and BED include increasing CBT disseminability, targeting affect regulation, and individualized stepped-care approaches.
anorexia nervosa; bulimia nervosa; binge eating disorder; eating disorders; therapy; medication; intervention; treatment
Preclinical evidence suggests that commonly used anesthetic agents induce long-lasting neurobehavioral changes when administered early in life but there has been virtually no attention to the neurodevelopmental consequences for the fetus of maternal anesthesia. This study tested the hypothesis that fetal rats exposed to isoflurane during maternal anesthesia on gestational day 14, which corresponds to the second trimester in humans, would be behaviorally abnormal as adults.
Timed, pregnant rats were randomly assigned on gestational day 14 to receive 1.4% isoflurane in 100% oxygen (N = 3) or 100 % oxygen (N = 2) for 4 h. Beginning at 8 weeks of age, male offspring were evaluated for spontaneous locomotor activity, hippocampal dependent learning and memory (spontaneous alternations, novel object recognition, and radial arm maze), and anxiety (elevated plus maze).
Isoflurane anesthesia was physiologically well tolerated by the dams. Adult rats exposed prenatally to isoflurane were not different than controls on spontaneous locomotor activity, spontaneous alternations, or object recognition memory but made more open arm entries on the elevated plus maze and took longer and made more errors of omission on the radial arm maze.
Rats exposed to isoflurane in utero at a time that corresponds to the second trimester in humans have impaired spatial memory acquisition and, reduced anxiety compared to controls. This suggests the fetal brain may be adversely affected by maternal anesthesia and raises the possibility that vulnerability to deleterious neurodevelopmental effects of isoflurane begins much earlier in life than previously recognized.
Purging disorder (PD), a recently recognized eating disorder syndrome, is differentiated from bulimia nervosa (BN) based on the absence of objectively large binge episodes. BN has been associated with low serum leptin levels. This study examined whether PD is also characterized by low serum leptin.
Participants included women with PD (n=20) or BN (n=37), and non-eating disorder controls (n=33). Blood samples for measurement of leptin and total ghrelin were obtained after overnight fast.
In comparison to control values, leptin levels were significantly decreased in PD (p<.01), as well as in BN (p<.02). Plasma ghrelin levels did not differ significantly across groups.
These results provide the first evidence that PD is associated with alteration in a neurobiological pathway influencing eating patterns and body weight. Further research is needed to assess whether low leptin levels in PD and BN are associated with restrained eating and weight suppression.
eating disorders; bulimia nervosa; leptin; ghrelin; appetite regulation; eating behavior
Puberty moderates genetic influences on disordered eating attitudes and behaviors, with little genetic influence before puberty but large (≥ 50%) genetic effects during and after puberty. To date, however, nothing is known about the mechanisms that underlie these effects. Estradiol is a particularly promising candidate, as estrogens become elevated at puberty and regulate gene transcription within neurotransmitter systems important for eating-related phenotypes. The aim of this pilot study was to examine whether estradiol levels moderate genetic influences on disordered eating during puberty.
Participants included 198 female twins (ages 10-15 years) from the Michigan State University Twin Registry. Disordered eating attitudes and behaviors were assessed with the total score, weight preoccupation, body dissatisfaction, and binge eating/compensatory behavior subscales of the Minnesota Eating Behavior Survey. Afternoon saliva samples were assayed for estradiol levels. Moderation of genetic effects was examined by comparing twin correlations in low versus high estradiol groups.
In the low estradiol group, monozygotic (MZ) and dizygotic (DZ) twin correlations for all MEBS scales were similar, suggesting little genetic influence. In the high estradiol group, the MZ twin correlation was more than double the DZ twin correlation, indicating the presence of genetic effects. Findings could not be accounted for by age, body mass index, or the physical changes of puberty.
Estradiol may be one important moderator of genetic effects on disordered eating during puberty. Larger twin studies are needed to replicate this pilot work and quantify the extent of genetic moderation.
Existing structural models of psychopathology need to be expanded to include additional diagnostic constructs beyond mood, anxiety, substance use, and antisocial behavior disorders. The goal of this study was to locate eating disorders within a hierarchical structural model of psychopathology that is anchored by broad Internalizing and Externalizing factors. Participants were female adolescent twins (N = 1,434) from the Minnesota Twin Family Study. We compared the fit of four models in which eating disorders (a) defined their own diagnostic class, (b) represented a subclass within Internalizing, (c) formed a subclass within Externalizing, and (d) were allowed to cross-load on both Internalizing and Externalizing. In the best-fitting model, eating disorders formed a sub-factor within Internalizing. These findings underscore the value of developing more comprehensive empirically based models of psychopathology to increase our understanding of diverse mental disorders.
eating disorders; disordered eating; comorbidity; diagnosis; and classification
Anorexia nervosa (AN) is a serious psychiatric illness associated with significant medical and psychiatric morbidity, psychosocial impairment, increased risk of death, and chronicity. Given the severity of the disorder, the establishment of safe and effective treatments is necessary. Several treatments have been tried in AN, but few favorable results have emerged. This paper reviews randomized controlled trials in AN, and provides a synthesis of existing data regarding the efficacy, safety, and adherence associated with pharmacologic and psychological interventions. Randomized controlled trials for the treatment of AN published in peer-reviewed journals were identified by electronic and manual searches. Overall, pharmacotherapy has limited benefits in the treatment of AN, with some promising preliminary findings associated with olanzapine, an antipsychotic agent. No single psychological intervention has demonstrated clear superiority in treating adults with AN. In adolescents with AN, the evidence base is strongest for the use of family therapy over alternative individual psychotherapies. Results highlight challenges in both treating individuals with AN and in studying the effects of those treatments, and further emphasize the importance of continued efforts to develop novel interventions. Treatment trials currently underway and areas for future research are discussed.
anorexia nervosa; treatment; pharmacotherapy; psychotherapy; randomized controlled trials
This analysis is a follow-up to an earlier investigation of 182 genes selected as likely candidate genetic variations conferring susceptibility to anorexia nervosa (AN). As those initial case-control results revealed no statistically significant differences in single nucleotide polymorphisms, herein we investigate alternative phenotypes associated with AN. In 1762 females using regression analyses we examined: (1) lowest illness-related attained body mass index; (2) age at menarche; (3) drive for thinness; (4) body dissatisfaction; (5) trait anxiety; (6) concern over mistakes; and (7) the anticipatory worry and pessimism vs. uninhibited optimism subscale of the harm avoidance scale. After controlling for multiple comparisons, no statistically significant results emerged. Although results must be viewed in the context of limitations of statistical power, the approach illustrates a means of potentially identifying genetic variants conferring susceptibility to AN because less complex phenotypes associated with AN are more proximal to the genotype and may be influenced by fewer genes.
covariates; eating disorders; association studies; personality; genetic
Extensive population-based genome-wide association studies have identified an association between the FTO gene and BMI; however, the mechanism of action is still unknown. To determine whether FTO may influence weight regulation through psychological and behavioral factors, seven single nucleotide polymorphisms (SNPs) of the FTO gene were genotyped in 1085 individuals with anorexia nervosa (AN) and 677 healthy weight controls from the international Price Foundation Genetic Studies of Eating Disorders. Each SNP was tested in association with eating disorder phenotypes and measures that have previously been associated with eating behavior pathology: trait anxiety, harm-avoidance, novelty seeking, impulsivity, obsessionality, compulsivity, and concern over mistakes. After appropriate correction for multiple comparisons, no significant associations between individual FTO gene SNPs and eating disorder phenotypes or related eating behavior pathology were identified in cases or controls. Thus, this study found no evidence that FTO gene variants associated with weight regulation in the general population are associated with eating disorder phenotypes in AN participants or matched controls.
We performed association studies with 5,151 SNPs that were judged as likely candidate genetic variations conferring susceptibility to anorexia nervosa (AN) based on location under reported linkage peaks, previous results in the literature (182 candidate genes), brain expression, biological plausibility, and estrogen responsivity. We employed a case–control design that tested each SNP individually as well as haplotypes derived from these SNPs in 1,085 case individuals with AN diagnoses and 677 control individuals. We also performed separate association analyses using three increasingly restrictive case definitions for AN: all individuals with any subtype of AN (All AN: n = 1,085); individuals with AN with no binge eating behavior (AN with No Binge Eating: n = 687); and individuals with the restricting subtype of AN (Restricting AN: n = 421). After accounting for multiple comparisons, there were no statistically significant associations for any individual SNP or haplotype block with any definition of illness. These results underscore the importance of large samples to yield appropriate power to detect genotypic differences in individuals with AN and also motivate complementary approaches involving Genome-Wide Association (GWA) studies, Copy Number Variation (CNV) analyses, sequencing-based rare variant discovery assays, and pathway-based analysis in order to make up for deficiencies in traditional candidate gene approaches to AN.
single nucleotide polymorphisms; probands; anorexia nervosa; bulimia nervosa