Treatment outcome in people with subthreshold compared with full-syndrome binge eating disorder

Objective: There is a controversial discussion in the literature as to whether individuals with subthreshold binge eating disorder (subBED) differ clinically significantly from individuals with full‐syndrome binge eating disorder (BED). This study was designed to compare eating‐related and general psychopathology at baseline and in response to a multimodal treatment program in obese people with subBED compared with BED. Research Methods and Procedures: A total of 96 obese participants (BMI ≥ 30 kg/m²) were assessed for eating‐related and general psychopathology at baseline. Thirty‐nine participants meeting criteria for BED and 19 participants meeting criteria for subBED attended a 15‐session outpatient group therapy including cognitive behavioral therapy extended by interpersonal therapy, nutritional counseling, and a supervised walking exercise. Participants with eating disorders were reassessed at the end of treatment and at 3‐month follow‐up. The obese control group without an eating disorder (n = 38) was assessed once. This was not a randomized controlled trial. Results: Intent‐to‐treat analyses revealed no differences between subBED and full‐syndrome BED participants with regard to eating‐related and general psychopathology at baseline and with regard to treatment outcome. All participants experienced substantial improvements, and the results remained stable during follow‐up (except for dietary restraint). At follow‐up, participants with subBED and BED remained different from non‐eating disorder controls in eating‐related but not general psychopathology. Discussion: The findings indicate that our multimodal treatment program is equally effective in obese subBED and BED participants, suggesting that a differentiation currently seems not to be of clinical significance.     

Teasing History,Onset of Obesity,Current Eating Disorder Psychopathology,Body Dissatisfaction,and Psychological Functioning in Binge Eating Disorder

Objective: The primary goal of this study was to examine associations among teasing history, onset of obesity, current eating disorder psychopathology, body dissatisfaction, and psychological functioning in women with Binge Eating Disorder (BED). Research Methods and Procedures: Subjects were 115 female adults who met DSM‐IV criteria for BED. Measurements assessing teasing history (general appearance [GAT] and weight and size [WST] teasing), current eating disorder psychopathology (binge frequency, eating restraint, and concerns regarding eating, shape, and weight), body dissatisfaction, and psychological functioning (depression and self‐esteem) were obtained. Results: History of GAT, but not WST, was associated with current weight concerns and body dissatisfaction, whereas both GAT and WST were significantly associated with current psychological functioning. Patients with earlier onset of obesity reported more WST than patients with later onset of obesity, but the groups did not differ significantly in GAT, current eating disorder psychopathology, body dissatisfaction, or psychological functioning. Obese women reported more WST than non‐obese women, but no differences in GAT or the other outcome variables were observed. Higher frequency of GAT was associated with greater binge frequency in obese women, and with greater eating restraint in non‐obese women. Discussion: Although physical appearance teasing history is not associated with variability in most eating disorder psychopathology, it is associated with related functioning, most notably body dissatisfaction, depression, and self‐esteem. Our findings also suggest that the age of onset of obesity and current body mass index status in isolation are not associated with eating psychopathology or associated psychological functioning in adult patients with BED.     

Energy Intake Patterns in Obese Women with Binge Eating Disorder

Objective: For binge eating disorder (BED) to be accepted as a distinct diagnostic category in the Diagnostic and Statistical Manual for Mental Disorders, Fifth Edition, it must be demonstrated that the criteria identify a diagnostic entity that is distinct from bulimia nervosa and obesity. This study examined the difference in total energy intake per day, patterns of energy intake throughout the day, and nutrient content of foods consumed in obese individuals who met the criteria for BED (on binge and non‐binge days) and those who did not. Research Methods and Procedures: Twenty women, 12 who met Diagnostic and Statistical Manual for Mental Disorders, Fourth Edition, criteria for BED and 8 matched obese controls, participated in the study. All participants underwent six random 24‐hour dietary recall telephone interviews conducted by experienced interviewers using the Nutrition Data Software System. Results: The BED group ingested significantly more kilocalories on days when they had binge eating episodes than the obese control group on average. The BED group ate significantly more in the evening on binge days than their control group counterparts. There is some indication in the data that those with BED may be restricting caloric intake. Finally, data indicated that the BED group ate significantly more protein, carbohydrate, and fat on binge days than on non‐binge days. However, the proportion of kilocalories from each nutrient shifted on BED binge days compared with non‐binge days to favor consumption of fat over carbohydrates. Discussion: More research needs to be done to determine if these findings are reproducible. Then, the neurobiological underpinnings of these differences in nutrient intake patterns and nutrient selection can be studied to help to determine the biological basis of the disorder.     

Self-Efficacy in Overweight Individuals with Binge Eating Disorder

MILLER, PETER M., JULIA A. WATKINS, ROGER G. SARGENT, AND EDWARD J. RICKERT. Self-efficacy in overweight individuals with binge eating disorder. Obes Res. Objective: To evaluate the relationship between self-efficacy judgments in obese individuals with binge eating disorder, “borderline” binge eating disorder, and no binge eating problems. Research Methods and Procedures: Before participation in a residential weight management program, 79 male and female subjects were administered the Weight Efficacy Lifestyle Questionnaire (WEL) and the Binge Eating Scale (BES). Based on DSM-IV diagnostic questions, subjects were categorized as BED, Borderline BED, or non-BED. Results: Krusal-Wallace Rank-Order analysis of variance revealed significant negative associations between binge eating and total WEL scores as well as the subscales of Negative Emotions, Social Pressure, Physical Discomfort, and Positive Activities. Differences were significant between the BED and the Borderline BED groups with the exception of the Social Pressure scale and the Total WEL scores. BED diagnosis as well as severity of binge eating were strongly associated with low self-efficacy ratings. Discussion: These results indicate that obese individuals with binge eating disorder demonstrate lower self-efficacy than those without this condition and that self-efficacy is related to the severity of binge eating.     

The Metabolic Syndrome and Behavioral Correlates in Obese Patients With Binge Eating Disorder

This study examined the frequency of the metabolic syndrome (MetSyn) and explored behavioral eating‐ and weight‐related correlates in obese patients with binge eating disorder (BED). Ninety‐three treatment‐seeking obese BED patients (22 men and 71 women) with and without the MetSyn were compared on demographic features and a number of current and historical eating and weight variables. Sixty percent of the obese patients with BED met criteria for the MetSyn, with men and whites having significantly higher rates than women and African Americans, respectively. Patients with vs. without coexisting MetSyn did not differ significantly in self‐reported frequency of binge eating or severity of eating disorder psychopathology. Multivariate hierarchical logistic regression analysis revealed that, after controlling for gender, ethnicity, and BMI, fewer episodes of weight cycling and regular meal skipping were significant predictors of the MetSyn. These findings suggest that lifestyle behaviors including weight loss attempts and regular meal consumption may be potential targets for prevention and/or treatment of the MetSyn in obese patients with BED.     

On the Relation of Attempting to Lose Weight,Restraint, and Binge Eating in Outpatients with Binge Eating Disorder

Objective: To examine the relationship among attempts to lose weight, restraint, and eating behavior in outpatients with binge eating disorder (BED). Research Methods and Procedures: Participants were 93 consecutive outpatients evaluated for a clinical trial who met Diagnostic and Statistical Manual, Fourth edition criteria for BED. The Eating Disorder Examination Interview was administered to assess attempts at weight loss, restraint, different forms of overeating, and the attitudinal psychopathology of eating disorders (i.e., concerns regarding eating, shape, and weight). In addition, the Three‐Factor Eating Questionnaire was used to assess cognitive restraint, hunger, and disinhibition. Psychometrically established measures were given to assess body dissatisfaction, depression, and self‐esteem. Results: The majority of participants (75.3%; N = 70) reported attempting to lose weight, but only 37.6% (N = 35) reported dietary restraint on at least half the days of the month. Dietary restraint and cognitive restraint were not associated with any form of binge eating or overeating. Dietary restraint and cognitive restraint were positively correlated with weight concern, shape concern, and body dissatisfaction, and negatively correlated with body mass index. To further examine the interplay between attempting to lose weight and restraint, three study groups were created: unrestrained nonattempters (21.5%, N = 20), unrestrained attempters (40.9%; N = 38), and restrained attempters (34.4%; N = 32). The three groups did not differ significantly on binge eating or other eating behaviors; however, significant differences were observed for weight concern, shape concern, and body dissatisfaction. Discussion: Attempts to lose weight and restraint are not synonymous for patients with BED. Although 75.3% of BED patients reported that they were attempting to lose weight, only 37.6% reported dietary restraint on at least half the days of the previous month. While restraint was negatively associated with body mass index, it was not related to binge eating or overeating. Our findings raise questions about prevailing models that posit restraint as a predominant factor in the maintenance of binge eating in BED.     

Binge eating behavior among a national sample of overweight and obese veterans

Objective:

Despite the high prevalence of overweight and obesity in the US military veterans, binge eating has not been examined in this population.

Design and Methods:

Using a secondary data analysis approach, the prevalence and correlates of self‐reported binge eating among 45,477 overweight or obese veterans receiving care in Veterans Health Administration facilities were examined. Participants completed a 23‐item survey that assessed demographics, weight history, physical and mental health comorbidities, and eating habits during routine medical clinic visits. χ² and logistic regression were used to examine the relationships among binge eating and demographic variables and medical and psychiatric comorbidities.

Results:

Nearly, three‐quarters of the sample reported clinically meaningful binge eating (i.e., two or more times per week). Binge‐eaters were more likely to report higher body mass index, depression, anxiety, and type 2 diabetes (P <0.0001). After controlling for potentially confounding variables, male veterans were significantly more likely to report clinically meaningful binge eating than female veterans (P < 0.001).

Conclusion:

These results have important implications for modifying weight management programs and highlight the need for the assessment and treatment to address binge eating, particularly among men and patients with type 2 diabetes.     

Eating disorder symptomatology in normal-weight vs. obese individuals with binge eating disorder

Although normal-weight individuals comprise a substantial minority of the binge eating disorder (BED) population, little is known about their clinical presentation. This study sought to investigate the nature and severity of eating disturbances in normal-weight adults with BED. We compared 281 normal-weight (n = 86) and obese (n = 195) treatment-seeking adults with BED (mean age = 31.0; s.d. = 10.8) on a range of current and past eating disorder symptoms using ANOVA and χ(2) analyses. After controlling for age and sex, normal-weight participants reported more frequent use of a range of healthy and unhealthy weight control behaviors compared to their obese peers, including eating fewer meals and snacks per day; exercising and skipping meals more frequently in the past month; and avoiding certain foods for weight control. They also endorsed more frequent attempts at dieting in the past year, and feeling more frequently distressed about their binge eating, at a trend level. There were no group differences in binge eating frequency in the past month, age at onset of binge eating, overvaluation of shape/weight, or likelihood of having used certain weight control behaviors (e.g., vomiting, laxative use) or having sought treatment for an eating disorder in the past. Based on our findings, normal-weight individuals appear to be a behaviorally distinct subset of the BED population with significantly greater usage of both healthy and unhealthy weight control behaviors compared to their obese peers. These results refute the notion that distress and impairment in BED are simply a result of comorbid obesity.     

Dieting Frequency in Obese Patients With Binge Eating Disorder: Behavioral and Metabolic Correlates

This study examined the clinical significance of self‐reported frequency of time spent dieting in obese patients with binge eating disorder (BED). A total of 207 treatment‐seeking obese BED patients (57 men and 150 women) were dichotomized by dieting frequency and gender and compared on a number of historical, psychological, and metabolic variables. Frequent dieters reported significantly earlier age of onset for binge eating, dieting, and obesity, more episodes of weight cycling, greater weight suppression, and greater eating disorder pathology than infrequent dieters; no differences, however, emerged on current binge eating frequency or psychological distress. Among women but not among men, frequent dieters had consistently lower chances of abnormalities in total cholesterol, high‐density lipoprotein (HDL) cholesterol, and the total/HDL cholesterol ratio while infrequent dieters had greater chances of abnormalities on these variables. Dietary restraint was inversely correlated with abnormalities in triglycerides, HDL cholesterol, and the total/HDL cholesterol ratio but was unrelated to low‐density lipoprotein (LDL) cholesterol. In summary, frequent dieters of both genders had greater lifetime and current eating and weight concerns, and in women, decreased chance of metabolic abnormalities than infrequent dieters. Our findings suggest that frequent dieting attempts, particularly in women, are associated with greater eating disorder pathology but may have a beneficial effect on metabolic functioning and cardiovascular disease risk independent of actual weight status. These findings may have implications for clinical advice provided to obese BED patients.     

Momentary affect surrounding loss of control and overeating in obese adults with and without binge eating disorder

Research suggests that loss of control (LOC) while eating (the sense that one cannot control what or how much one is eating) is a more salient feature of binge eating than the amount of food consumed. This study examined the unique contributions of LOC and episode size to negative affect surrounding eating episodes in binge eating disorder (BED) and obesity. Twenty-two obese adults with (n = 9) and without (n = 13) BED completed daily records of eating patterns and mood using ecological momentary assessment (EMA). Linear mixed modeling revealed that across groups, greater premeal self-reported LOC was associated with higher premeal negative affect independent of episode size. For individuals with BED, greater premeal self-reported LOC was associated with higher postmeal negative affect, regardless of the amount of food eaten, whereas for obese controls, the combination of LOC and consumption of large amounts of food was associated with lower postmeal negative affect. Results indicate that LOC, but not the quantity of food consumed, is associated with momentary distress related to aberrant eating in BED. Findings also highlight the need for further research investigating the emotional context surrounding aberrant eating in obese individuals without BED.     

Appearance vs. Health Reasons for Seeking Treatment Among Obese Patients with Binge Eating Disorder

Objectives : This study examined reasons for seeking treatment reported by obese patients diagnosed with binge eating disorder (BED). Research Methods and Procedures : Participants were 248 adults (58 men and 190 women) who met DSM criteria for BED. Participants were recruited through advertisements for treatment studies looking for persons who wanted to “stop binge eating and lose weight.” Patients’ reasons for seeking treatment were examined with respect to demography (gender and age), obesity (BMI and age of onset), features of eating disorders, and associated psychological functioning (depression and self‐esteem). Results : Of the 248 participants, 64% reported health concerns and 36% reported appearance concerns as their primary reason for seeking treatment. Reasons for seeking treatment did not differ significantly by gender. Patients seeking treatment because of appearance‐related reasons had lower BMIs than those reporting health‐related reasons (34.8 vs. 38.5, respectively), but they reported greater body dissatisfaction, more features of eating disorders, and lower self‐esteem. Discussion : Reasons that prompt treatment seeking among obese individuals with BED reflect meaningful patient characteristics and, therefore, warrant assessment and consideration during treatment planning. Further research is needed to determine whether reasons for treatment seeking among different obese patient groups affect treatment outcomes.     

Binge eating disorder and the outcome of bariatric surgery at one year: a prospective, observational study

Previous studies have suggested that binge eating disorder (BED) impairs weight loss following bariatric surgery, leading some investigators to recommend that patients receive behavioral treatment for this condition before surgery. However, many of these investigations had significant methodological limitations. The present observational study used a modified intention-to-treat (ITT) population to compare 1-year changes in weight in 59 surgically treated participants, determined preoperatively to be free of a current eating disorder, with changes in 36 individuals judged to have BED. Changes in weight and binge eating in the latter group were compared with those in 49 obese individuals with BED who sought lifestyle modification for weight loss. BED was assessed using criteria proposed for the Diagnostic and Statistical Manual (DSM) 5. At 1 year, surgically treated participants without BED lost 24.2% of initial weight, compared with 22.1% for those with BED (P > 0.309). Both groups achieved clinically significant improvements in several cardiovascular disease (CVD) risk factors. Participants with BED who received lifestyle modification lost 10.3% at 1 year, significantly (P < 0.001) less than surgically treated BED participants. The mean number of binge eating days (in the prior 28 days) fell sharply in both BED groups at 1 year. These two groups did not differ significantly in BED remission rates or in improvements in CVD risk factors. The present results, obtained in carefully studied participants, indicate that the preoperative presence of BED does not attenuate weight loss or improvements in CVD risk factors at 1 year in surgically treated patients. Longer follow-up of participants is required.     

Binge Eating Disorder: Current Knowledge and Future Directions

Binge eating disorder (BED) is a newly characterized eating disorder that encompasses individuals who have severe distress and dysfunction due to binge eating, but who do not regularly engage in inappropriate compensatory behaviors. While relatively uncommon in the general community, BED becomes more prevalent with increasing severity of obesity. BED is associated with early onset of obesity, frequent weight cycling, body shape disparagement, and psychiatric disorders. These associations occur independent of the degree of obesity. Although many individuals with BED have good short-term weight loss regardless of treatment modality, as a group they may be prone to greater attrition during weight-loss treatment and more rapid regain of lost weight. Current treatments geared toward binge eating behaviors include antidepressant medications, cognitive behavioral psychotherapy, and interpersonal psychotherapy; however, these treatments have little efficacy in promoting weight loss, and only modest success in long-term reduction of binge eating. As a significant proportion of obese individuals entering weight-loss treatment and research programs are likely to meet criteria for BED, those conducting clinical research should be aware of this distinct subgroup and determine the contribution of BED to outcome measures. (OBESITY RESEARCH 1993; 1:306–324)     

Loss of control is central to psychological disturbance associated with binge eating disorder

Objective: Binge eating disorder (BED) is positively associated with obesity and psychological distress, yet the behavioral features of BED that drive these associations are largely unexplored. The primary aim of this study was to investigate which core behavioral features of binge eating are most strongly related to psychological disturbance. Methods and Procedures: A cross‐sectional study involved 180 bariatric surgery candidates, 93 members of a non‐surgical weight loss support group, and 158 general community respondents (81 men/350 women, mean age 45.8 ± 13.3, mean BMI 34.8 ± 10.8, BMI range 17.7–66.7). Validated questionnaires assessed BED and binge eating, symptoms of depression, appearance dissatisfaction (AD), quality of life (QoL) and eating‐related behaviors. Features of binge eating were confirmed by interview. BMI was determined by clinical assessment and self‐report. Results: The loss of control (LOC) over eating, that is, being unable to stop eating or control what or how much was consumed was most closely related to psychological markers of distress common in BED. In particular, those who experienced severe emotional disturbance due to feelings of LOC reported higher symptoms of depression (P < 0.001), AD (P = 0.009), and poorer mental health–related QoL (P = 0.027). Discussion: Persons who report subjective binge episodes or do not meet BED frequency criteria for objective binge episodes may still be at elevated risk of psychological disturbance and benefit from clinical intervention. Feelings of LOC could drive binge eaters to seek bariatric surgery in an attempt to gain control over body weight and psychologically disturbing eating behavior.     

Binge Eating Behavior in Patients with Eating Disorders

The purpose of this study was to determine whether the objectively observed binge eating behavior of obese subjects meeting the proposed DSM-IV criteria for binge eating disorder would be similar to that observed in patients with bulimia nervosa. Non-obese patients with bulimia nervosa (BN), obese subjects with binge eating disorder (BED), obese and non-obese women without eating disorders were each instructed to binge eat single- and multiple-item meals. In the multiple-item meal, the obese subjects with BED ate significantly more (1515 kcal) than obese subjects without BED (1115 kcal), but they ate less than the normal-weight bulimic patients (2680 kcal). The non-obese controls ate amounts similar to the obese non-binge-eating-disordered group (1093 and 1115.2 kcal, respectively). In the single-item meal, consisting of ice cream, patients with BN ate significantly more than any other group (1307 kcal), while obese subjects with or without binge-eating disorder ate significantly more (762 kcal) than non-obese controls (308 kcal). This study has demonstrated that although both BN and BED are characterized by recurrent episodes of binge eating, quantitatively there appear to be differences between the eating disturbances in the two disorders. Because single- and multiple-item meals differ in external cues, these results also suggest that the obese subjects with BED may be disinhibited by external cues, while obese subjects without BED may be inhibited by external cues.     

Association of major depression and binge eating disorder with weight loss in a clinical setting

Objective: Obesity has been linked to both major depressive disorder (MDD) and binge eating disorder (BED) in clinical and epidemiological studies. The present study compared weight loss among patients with and without MDD and BED who participated in a hospital‐based weight loss program modeled after the Diabetes Prevention Program. Research Methods and Procedures: Of 131 obese patients who enrolled in treatment, 17% were diagnosed with MDD only, 13% were diagnosed with BED only, 17% were diagnosed with both MDD and BED, and 53% lacked either diagnosis in a pretreatment clinical interview. Results: After treatment, patients with MDD only attained 63% of the weight loss that non‐depressed patients attained. Patients with BED only attained 55% of the weight loss that non‐binge eaters attained. The effect of MDD on weight loss was not accounted for by the presence of BED or vice versa. Only 27% of patients with both MDD and BED achieved clinically significant weight loss compared with 67% of patients who had neither disorder. Results were not significantly altered when gender, age, and diabetes status were adjusted. Conclusion: Both MDD and BED were prevalent among this obese clinical population, and each disorder was independently associated with worse outcomes. Research is needed to investigate how to increase the efficacy of behavioral weight loss programs for individuals with MDD and/or BED.     

Enhanced striatal dopamine release during food stimulation in binge eating disorder

Subjects with binge eating disorder (BED) regularly consume large amounts of food in short time periods. The neurobiology of BED is poorly understood. Brain dopamine, which regulates motivation for food intake, is likely to be involved. We assessed the involvement of brain dopamine in the motivation for food consumption in binge eaters. Positron emission tomography (PET) scans with [(11)C]raclopride were done in 10 obese BED and 8 obese subjects without BED. Changes in extracellular dopamine in the striatum in response to food stimulation in food-deprived subjects were evaluated after placebo and after oral methylphenidate (MPH), a drug that blocks the dopamine reuptake transporter and thus amplifies dopamine signals. Neither the neutral stimuli (with or without MPH) nor the food stimuli when given with placebo increased extracellular dopamine. The food stimuli when given with MPH significantly increased dopamine in the caudate and putamen in the binge eaters but not in the nonbinge eaters. Dopamine increases in the caudate were significantly correlated with the binge eating scores but not with BMI. These results identify dopamine neurotransmission in the caudate as being of relevance to the neurobiology of BED. The lack of correlation between BMI and dopamine changes suggests that dopamine release per se does not predict BMI within a group of obese individuals but that it predicts binge eating.     

Different Methods for Assessing the Features of Eating Disorders in Patients with Binge Eating Disorder: A Replication

Objective: To compare different methods for assessing the features of eating disorders in patients with binge eating disorder (BED). Research Methods and Procedures: A total of 47 participants with BED were administered the Eating Disorder Examination (EDE) Interview and completed the EDE‐Questionnaire (EDE‐Q) at baseline. A total of 37 participants prospectively self‐monitored their eating behaviors daily for 4 weeks and then completed another EDE‐Q. Results: At baseline, the EDE and the EDE‐Q were significantly correlated on frequencies of objective bulimic episodes (binge eating), overeating episodes, and on the dietary restraint, eating concern, weight concern, and shape concern subscales. Mean differences in the EDE and EDE‐Q frequencies of objective bulimic episodes and overeating were not significant but scores on the four subscales differed significantly, with the EDE‐Q yielding higher scores. At the 4‐week point, the EDE‐Q retrospective 28‐day assessment was significantly correlated with the prospective daily self‐monitoring records for frequency of objective bulimic episodes and the mean difference between the methods was not significant. The EDE‐Q and self‐monitoring findings for subjective bulimic episodes and objective overeating differed significantly. Discussion: In patients with BED, the three assessment methods showed some areas of acceptable convergence.     

Impulsivity in Binge Eating Disorder: Food Cues Elicit Increased Reward Responses and Disinhibition

Background

Binge eating disorder (BED) represents a distinct eating disorder diagnosis. Current approaches assume increased impulsivity to be one factor leading to binge eating and weight gain. We used eye tracking to investigate both components of impulsivity, namely reward sensitivity and rash-spontaneous behaviour towards food in BED for the first time.

Methods

Overweight and obese people with BED (BED+; n = 25), without BED (BED−; n = 26) and healthy normal-weight controls (NWC; n = 25) performed a free exploration paradigm measuring reward sensitivity (experiment 1) and a modified antisaccade paradigm measuring disinhibited, rash-spontaneous behaviour (experiment 2) using food and nonfood stimuli. Additionally, trait impulsivity was assessed.

Results

In experiment 1, all participants located their initial fixations more often on food stimuli and BED+ participants gazed longer on food stimuli in comparison with BED− and NWC participants. In experiment 2, BED+ participants had more difficulties inhibiting saccades towards food and nonfood stimuli compared with both other groups in first saccades, and especially towards food stimuli in second saccades and concerning sequences of first and second saccades. BED− participants did not differ significantly from NWC participants in both experiments. Additionally, eye tracking performance was associated with self-reported reward responsiveness and self-control.

Conclusions

According to these results, food-related reward sensitivity and rash-spontaneous behaviour, as the two components of impulsivity, are increased in BED in comparison with weight-matched and normal-weight controls. This indicates that BED represents a neurobehavioural phenotype of obesity that is characterised by increased impulsivity. Interventions for BED should target these special needs of affected patients.     

Dopamine for “Wanting” and Opioids for “Liking”: A Comparison of Obese Adults With and Without Binge Eating

Obesity research suffers from an overinclusion paradigm whereby all participants with a BMI beyond a certain cutoff value (e.g., 30) are typically combined in a single group and compared to those of normal weight. There has been little attempt to identify meaningful subgroups defined by their salient biobehavioral differences. In order to address this limitation, we examined genetic and psychological indicators of hedonic eating in obese adults with (n = 66) and without (n = 70) binge eating disorder (BED). Our analyses focused on dopamine (DA) and opioid genetic markers because of their conjoint association with the functioning of brain reward mechanisms. We targeted three functional polymorphisms related to the D2 receptor (DRD2) gene, as well as the functional A118G polymorphism of the mu‐opioid receptor (OPRM1) gene. We found that significantly more obese controls had the “loss‐of‐function” A1 allele of Taq1A compared to their BED counterparts, whereas the “gain‐of‐function” G allele of A118G occurred with greater frequency in the BED group. A significant gene–gene combination χ² analysis also indicated that of those participants with the gain‐gain genotype (G⁺ and A1), 80% were in the BED group whereas only 35% with the loss‐loss genotype (G^? and A1⁺) were in this group. Finally, BED subjects had significantly higher scores on a self‐report measure of hedonic eating. Our findings suggest that BED is a biologically based subtype of obesity and that the proneness to binge eating may be influenced by a hyper‐reactivity to the hedonic properties of food—a predisposition that is easily exploited in our current environment with its highly visible and easily accessible surfeit of sweet and fatty foods.