Binge eating: a theoretical review

Genetic differences in the behavioral organization of binge eating, conditioned food reward, and compulsive-like eating in C57BL/6J and DBA/2J strains

Binge eating (BE) is a heritable symptom of eating disorders associated with anxiety, depression, malnutrition, and obesity. Genetic analysis of BE could facilitate therapeutic discovery. We used an intermittent, limited access BE paradigm involving sweetened palatable food (PF) to examine genetic differences in BE, conditioned food reward, and compulsive-like eating between C57BL/6J (B6J) and DBA/2J (D2J) inbred mouse strains. D2J mice showed a robust escalation in intake and conditioned place preference for the PF-paired side. D2J mice also showed a unique style of compulsive-like eating in the light/dark conflict test where they rapidly hoarded and consumed PF in the preferred unlit environment. BE and compulsive-like eating exhibited narrow-sense heritability estimates between 56 and 73%. To gain insight into the genetic basis, we phenotyped and genotyped a small cohort of 133 B6J × D2J-F₂ mice at the peak location of three quantitative trait loci (QTL) previously identified in F₂ mice for sweet taste (chromosome 4: 156 Mb), bitter taste (chromosome 6: 133 Mb) and behavioral sensitivity to drugs of abuse (chromosome 11: 50 Mb). The D2J allele on chromosome 6 was associated with greater PF intake on training days and greater compulsive-like PF intake, but only in males, suggesting that decreased bitter taste may increase BE in males. The D2J allele on chromosome 11 was associated with an increase in final PF intake and slope of escalation across days. Future studies employing larger crosses and genetic reference panels comprising B6J and D2J alleles will identify causal genes and neurobiological mechanisms.

Behavioural implications of traditional treatment and closed-loop automated insulin delivery systems in Type 1 diabetes: applying a cognitive restraint theory framework

As the prevalence of obesity in Type 1 diabetes rises, the effects of emerging therapy options should be considered in the context of both weight and glycaemic control outcomes. Artificial pancreas device systems will 'close the loop' between blood glucose monitoring and automated insulin delivery and may transform day-to-day dietary management for people with Type 1 diabetes in multiple ways. In the present review, we draw directly from cognitive restraint theory to consider unintended impacts that closed-loop systems may have on ingestive behaviour and food intake. We provide a brief overview of dietary restraint theory and its relation to weight status in the general population, discuss the role of restraint in traditional Type 1 diabetes treatment, and lastly, use this restraint framework to discuss the possible behavioural implications and opportunities of closed-loop systems in the treatment of Type 1 diabetes. We hypothesize that adopting closed-loop systems will lift the diligence and restriction that characterizes Type 1 diabetes today, thus requiring a transition from a restrained eating behaviour to a non-restrained eating behaviour. Furthermore, we suggest this transition be leveraged as an opportunity to teach people lifelong eating behaviour to promote healthy weight status by incorporating education and cognitive reappraisal. Our aim was to use a transdisciplinary approach to highlight critical aspects of the emerging closed-loop technologies relating to eating behaviour and weight effects and to promote discussion of strategies to optimize long-term health in Type 1 diabetes via two key outcomes: glycaemic control and weight management.

Applied Interventions in the Prevention and Treatment of Obesity Through the Research of Professor Jane Wardle

PURPOSE OF REVIEW

Obesity presents a challenge for practitioners, policy makers, researchers and for those with obesity themselves. This review focuses on psychological approaches to its management and prevention in children and adults.

RECENT FINDINGS

Through exploring the work of the late Professor Jane Wardle, we look at the earliest behavioural treatment approaches and how psychological theory has been used to develop more contemporary approaches, for example incorporating genetic feedback and habit formation theory into interventions. We also explore how Jane has challenged thinking about the causal pathways of obesity in relation to eating behaviour. Beyond academic work, Jane was an advocate of developing interventions which had real-world applications. Therefore, we discuss how she not only developed new interventions but also made these widely available and the charity that she established.

Bulimia: A Literature Review

This article provides a literature review of bulimia. It examines the condition and its prevalence, features and complications.

A Brunswikian Model for Body Image Research in Patients with Eating Disorders

Eating disorders have become a national healthl problem, particularly among adolescent girls. Of particular interest with these patienils is their inability to perceive themselves accurately. While many studies have addressed body image distortion, the cognitive process involved has remained elusive. Rather than study this individual process with a group comparisont ietehodology, Brunswik's lens model was employed. Patienits' individual cognitive models were explored prior to aggregating the data on a group level. Impor tant differ enices emerged between anorexic, bulimic, obese, anrd normal female's utilizatioin of available perceptual cues concerning self and other body sizes. All of the participants in the study demonstrated conzsistenti linear models for use of perceptual cue information. Group differenices emerged in relative emphasis placed on each cue. This luse of Brunswik's lens model represents a uniquie applicationi of the methodology that should prove inivalitable for-future studies of self-per-ceptioni in a wide variety of domains.

Cognitive-Behavioural Treatment of Bulimia Nervosa

This paper reviews the literature on cognitive-behavioural treatment of bulimia nervosa, including the rationale and procedure for including an exposure plus response-prevention component. Comparisons of the full cognitive-behavioural therapy package to no treatment, other forms of psychotherapy, and pharmacotherapy are evaluated. The evidence suggests that cognitive-behavioural therapy is a relatively effective treatment for bulimia nervosa, although long-term outcome is still far from optimal.

From disordered eating to addiction: the "food drug" in bulimia nervosa

The high prevalence of substance abuse in individuals with bulimia nervosa (BN) and the pervasive symptom substitution in many types of drug addiction suggest that a number of substances--including food--can impair an individual's self-control, even in the presence of negative consequences. Nonetheless, the neurobiological similarities between BN and drug addiction are not clearly established. This review explores how the specific eating patterns seen in BN (binge eating and purging, with intermittent dietary restriction) are particularly addictive and differentiate BN from other eating disorders and obesity. A number of peripheral and central biological aberrations seen in BN may result in altered reward sensitivity in these individuals, particularly through effects on the dopaminergic system. Neurobiological findings support the notion that BN is an addictive disorder, which has treatment implications for therapy and pharmacological manipulations.

Dietary restraint moderates genetic risk for binge eating

Dietary restraint is a prospective risk factor for the development of binge eating and bulimia nervosa. Although many women engage in dietary restraint, relatively few develop binge eating. Dietary restraint may increase susceptibility for binge eating only in individuals who are at genetic risk. Specifically, dietary restraint may be a behavioral exposure factor that activates genetic predispositions for binge eating. We investigated this possibility in 1,678 young adolescent and adult same-sex female twins from the Minnesota Twin Family Study and the Michigan State University Twin Registry. Twin moderation models were used to examine whether levels of dietary restraint moderate genetic and environmental influences on binge eating. Results indicated that genetic and nonshared environmental factors for binge eating increased at higher levels of dietary restraint. These effects were present after controlling for age, body mass index, and genetic and environmental overlap among dietary restraint and binge eating. Results suggest that dietary restraint may be most important for individuals at genetic risk for binge eating and that the combination of these factors could enhance individual differences in risk for binge eating.

Asymmetric prefrontal cortex activation in relation to markers of overeating in obese humans

Dietary restraint is heavily influenced by affect, which has been independently related to asymmetrical activation in the prefrontal cortex (prefrontal asymmetry) in electroencephalograph (EEG) studies. In normal weight individuals, dietary restraint has been related to prefrontal asymmetry; however, this relationship was not mediated by affect. This study was designed to test the hypotheses that, in an overweight and obese sample, dietary restraint as well as binge eating, disinhibition, hunger, and appetitive responsivity would be related to prefrontal asymmetry independent of affect at the time of assessment. Resting EEG recordings and self-report measures of overeating and affect were collected in 28 overweight and obese adults. Linear regression analyses were used to predict prefrontal asymmetry from appetitive measures while controlling for affect. Cognitive restraint and binge eating were not associated with prefrontal asymmetry. However, disinhibition, hunger, and appetitive responsivity predicted left-, greater than right-, sided prefrontal cortex activation independent of affect. Findings in this study add to a growing literature implicating the prefrontal cortex in the cognitive control of dietary intake. Further research to specify the precise role of prefrontal asymmetry in the motivation toward, and cessation of, feeding in obese individuals is encouraged.

Restrained Eating and Risk of Gaining Weight and Body Fat in Middle-Aged Women: A 3-Year Prospective Study

Purpose.

Examine the extent to which restrained eating (RE) and changes in RE influence the risk of weight and fat gain over 36 months in women.

Design.

Prospective cohort.

Setting.

Several communities.

Subjects.

Baseline and follow-up assessments were completed by 192 middle-aged women (ages 40.0 ± 3 years).

Measures.

Body weight was measured with an electronic scale, body fat (BF) was assessed using the Bod Pod, energy intake was evaluated using 7–day weighed food records, physical activity was measured objectively using accelerometers, and RE was indexed using the Dutch Eating Behavior Questionnaire.

Analysis.

Relative risk (RR) was calculated using incidence data.

Results.

The risk of weight gain (> 1 kg) over the 36 months was 69% greater in women who did not increase in RE compared with their counterparts (RR = 1.69, 95% confidence interval [CI] = 1.12–2.52). The risk of substantial weight gain (≥3 kg) was 138% greater in women who did not increase in RE compared with women who did (RR = 2.38, 95% CI = 1.16–4.89), and the risk of gains in BF (≥ 1% point) was 49%) greater (RR = 1.49, 95% CI = 1.02–2.17). Control of potential confounding factors, except changes in energy intake, had little influence on risk.

Conclusion.

Women who do not become more restrained in their eating over time are at much greater risk of gaining weight and BF compared with those who become more restrained.

Psychopathology and obesity

Obesity has historically been linked to emotional factors by clinicians and the lay public alike. Early psychiatric studies reinforced the popular perception that psychopathology is common among the overweight and plays an important role in the development of obesity. This notion has been challenged by recent investigations which suggest that psychological disturbances are more likely to be the consequences than the causes of obesity. Emotional difficulties faced by the obese may be largely attributable to an entrenched cultural contempt for the obese and a pervasive preoccupation with thinness.

Opioid modulation of taste hedonics within the ventral striatum

There is a long-standing interest in the role of endogenous opioid peptides in feeding behavior and, in particular, in the modulation of food reward and palatability. Since drugs such as heroin, morphine, alcohol, and cannabinoids, interact with this system, there may be important common neural substrates between food and drug reward with regard to the brain's opioid systems. In this paper, we review the proposed functional role of opioid neurotransmission and mu opiate receptors within the nucleus accumbens and surrounding ventral striatum. Opioid compounds, particularly those selective for the mu receptor, induce a potent increase in food intake, sucrose, salt, saccharin, and ethanol intake. We have explored this phenomenon with regard to macronutrient selection, regional specificity, role of output structures, Fos mapping, analysis of motivational state, and enkephalin gene expression. We hypothesize that opioid-mediated mechanisms within ventral striatal medium spiny neurons mediate the affective or hedonic response to food ('liking' or food 'pleasure'). A further refinement of this hypothesis is that activation of ventral striatal opioids specifically encodes positive affect induced by tasty and/or calorically dense foods (such as sugar and fat), and promotes behaviors associated with this enhanced palatability. It is proposed that this brain mechanism was beneficial in evolutionary development for ensuring the consumption of relatively scarce, high-energy food sources. However, in modern times, with unlimited supplies of high-calorie food, it has contributed to the present epidemic of obesity.

The relationship between quality of life and perceived body weight and dieting history in Dutch men and women

OBJECTIVES

(1) To study the relationship between quality of life (QoL) and measured and perceived weight and dieting history in Dutch men and women; (2) to assess the effect of weight loss over a 5 y period on QoL.

DESIGN

A cross-sectional study, in a sub-sample longitudinal over 5 y.

SUBJECTS

A total of 2155 men and 2446 women, aged 20-59 and recruited from the general population from three towns in The Netherlands.

MEASUREMENTS

Body weight, height, self-administered questionnaire including questions concerning demographic variables and weight loss practices as part of the Dutch Monitoring project on Risk Factors for Chronic Disease (MORGEN). The Rand-36 questionnaire was used as the QoL measure.

RESULTS

In men, measured overweight (body mass index, BMI>25 kg/m(2)) was not associated with any dimension of QoL after adjustment for age, educational level and perceived overweight. Perceived overweight was related to reduced scores for general health and vitality. This relationship was independent of measured obesity. A history of repeated weight loss was associated with reduced scores for role functioning due to both physical and emotional problems. In women, measured overweight was significantly associated with lower scores for five out of eight QoL dimensions and perceived overweight with three: general health, vitality and physical functioning. A history of frequent weight loss was related to significantly reduced scores in six dimensions. However, only with history of frequent weight loss, and uniquely in women, was there a significant reduction in scores on mental health and limited emotional role functioning. Measured and perceived overweight and frequent weight loss were all related to reduced scores for physical functioning. Longitudinal data indicate that in older women weight gain of 10% body weight or more was associated with a significant deterioration in QoL.

CONCLUSIONS

When looking at measures of QoL in relation to overweight it is important to separate the effects of perception of weight status and history of weight loss. We observed that the latter two factors were associated with reduced scores on several dimensions of QoL, particularly in women. These associations were observed to be independent of body weight.

Relationship between dietary restraint, binge eating, and leptin in obese women

OBJECTIVE

To describe some biological, behavioural and psychological correlates of the Three-Factor Eating Questionnaire, and to determine the relationship between dietary restraint, binge eating, and leptin among obese women seeking treatment.

DESIGN

Consecutive series of obese women enrolled in a clinical program for weight reduction treatment.

SUBJECTS

Forty-two obese women. Eight participants met the criteria for 'severe binge eating' as measured by the Binge Eating Scale.

MEASUREMENTS

Energy intake, resting energy expenditure, body composition, leptin, restraint, disinhibition, hunger and binge eating were assessed before starting the treatment.

RESULTS

In this sample both higher disinhibition and hunger scores were associated with greater binge eating severity. Obese women with severe binge eating had lower restraint, higher disinhibition and hunger scores, as well as higher daily fat intake, when compared with obese non-binge-eaters. Interestingly, restraint scores were negatively associated with leptin levels among subjects with severe binge eating.

CONCLUSION

In obese women with severe binge eating, the negative relationship between dietary restraint and serum leptin concentrations seems mediated by a greater fat intake. These findings need to be verified in further human studies.

Multidimensionality in adolescent eating problems. A two-phase measurement study

The aims of this study were, firstly, to examine the factor structure of single items from several self-report methods used to measure eating disorder symptoms, and secondly, in search for a short assessment instrument to reduce the number of items within each factor. Factor analyses were employed to identify and confirm the constructs measured by a total of sixty items drawn from these assessment methods. In phase one, 508 secondary school pupils were recruited as subjects, and principal factor analysis identified three factors; body concern, dieting, and loss of control over eating. Twenty-nine items were retained, and in phase two subjected to a second data collection among 4129 secondary school pupils. Confirmatory factor analysis was employed to cross-validate the factor structure from phase one. The three-factor structure was confirmed satisfactorily for boys, but not for girls aged 12-14 years. For girls aged 14-16 years, it was confirmed when a number of items were omitted. The findings are discussed in relation to restraint theory and the continuum hypothesis.

Prefrontal and striatal dopamine metabolism during enhanced rebound hyperphagia induced by space restriction--a rat model of binge eating

BACKGROUND

Several lines of evidence indicate that abnormalities in brain dopamine and serotonin metabolism may play an important role in bulimia nervosa. However, the regional neurochemical mechanism of the binge eating is poorly understood. Our purpose was to elucidate brain neurochemical mechanisms of binge eating using a rat model.

METHODS

The dopamine release and metabolism in the prefrontal cortex (PFC) and in the ventrolateral striatum (VLS) of rats were studied using microdialysis during enhanced rebound hyperphagia induced by space restriction (an animal model of binge eating).

RESULTS

The rats showed rebound hyperphagic state when they were released from scheduled feeding (2 hours/day feeding for 7 days). The hyperphagia was further enhanced when they were put in a space-restricted cage where their mobility was restricted. Dopamine release and metabolism were increased both in the PFC and in the VLS during the enhanced rebound hyperphagia.

CONCLUSIONS

These results tentatively suggest that increased dopamine release and metabolism in the PFC and in the VLS may be related to space restriction and to activation of motor function involved in feeding behavior, respectively. The enhanced rebound hyperphagia induced by space restriction may be useful as an animal model of binge eating.

A learning model of binge eating: cue reactivity and cue exposure

In the present article, a learning model of binge eating is presented. It has been hypothesized that, parallel to drug intake, the craving and excessive food intake of binge eaters is cue controlled. Research in support of the model is reviewed and a series of predictions about clinical and non-clinical issues is derived from the model. Amongst other things, the model predicts that binge eating might be successfully treated with cue exposure and response prevention. Practical issues are discussed and preliminary pilot studies on cue exposure for bingers are reviewed.

Cue reactivity to food- and body-related stimuli in restrained and unrestrained eaters

In the present study, psychophysiological cue reactivity was monitored in 11 restrained (nonclinical but disinhibitive) and 13 unrestrained (control) subjects. The cues consisted of slides depicting either personally "favourite" binge food items or the subject's own body. The parameters monitored included skin conductance, heart rate, startle eyeblink EMG, and facial (corrugator and zygomatic) EMG. Although for several parameters the expected main effect of slide type was found, no between-group differences in cue reactivity could be demonstrated. Several explanations of the present finding, as well as possible future directions for cue reactivity research, are discussed, with emphasis placed upon the role of classical conditioning in eating disorders.

Locating reward cue at response manipulandum (CAM) induces symptoms of drug abuse

Appetitive instrumental discrimination learning procedures provide for CAM (cue and manipulandum) when the reward cue (discriminative stimulus positively correlated with positive reinforcement) is located at the response manipulandum (object that when contacted or manipulated defines the performance of the instrumental response). Evidence reviewed shows that CAM induces excessive and compulsive instrumental responding relative to otherwise comparable non-CAM control procedures. In humans, symptoms of drug abuse are particularly likely when the drug-taking implement (response manipulandum at which instrumental drug-taking is directed) is also predictive of the drug's rewarding effects (reward cue). Evidence that the predictive relationship between a drug-taking implement and drug reward relates to drug abuse is reviewed, and implications for treatment and prevention are considered. CAM is related to neurobiological models of drug abuse that emphasize the role of the neurotransmitter dopamine (DA). CAM produces convergence of DA-mediated responding for conditioned reinforcement with DA mediation of psychomotor activation and incentive-motivational processes to yield reflexive cue-directed responding not observed in non-CAM controls.

Eating style and symptoms of eating disorders: further explorations

Based on earlier efforts to document relationships between eating styles involving hunger, deprivation, and restraint and symptoms of eating disorders, three scales--Eating Style, Feeling Deprived, and Dieting Style--were created and administered to 259 University females, 118 males, and 50 nonstudent females. Of interest were psychometric properties of the scales, their relationships to each other and with symptoms, beliefs about weight control, and body weight. One year later, findings based on Eating Style were replicated and extended in smaller groups of the original University subjects. Appreciable relationships occurred almost uniformly between Eating Style (addressing hunger, deprivation, and restraint) and proposed correlates. Feeling Deprived (a measure of avowed deprivation) correlated consistently with beliefs about weight control and weight variables, but not symptoms. Measurement of Dieting Style was hampered by small ns.

Restraint and perception of body weight among British adults

A sample of 533 adults (268 women and 265 men) representative of the general population of Great Britain were interviewed so that the extent and effects of restraint, using the Dutch Eating Behaviour Questionnaire (DEBQ; Van Strien, Frijters, Bergers, & Defares, 1986) and the extent of overestimation of body weight could be examined. High-restraint subjects reported more guilt about food and eating and a greater likelihood of overeating in reaction to dysphoric mood, and they were more apt to overestimate their body size. Women reported significantly higher restraint, more guilt after eating in various types of social situations, and more overeating in reaction to dysphoric mood. Higher social class was associated with reports of guilt about a greater number of foods and with reports of more overeating when under stress or tired. Age was positively associated with guilt and negatively associated with overeating in reaction to being under stress, tired, or depressed.

The psychometric properties of the Eating Attitude Test in a non-Western population

The psychometric features of the Eating Attitude Test Questionnaire (EAT) are described in an Egyptian population of secondary school girls (n = 351). Confirmatory factor analysis, modelled on studies by Garner et al. (1982) and Eisler and Szmukler (1985), was conducted and pointed to the overall coherence of the EAT in this population. The assessment of the internal validity of each factor, however, showed a high level of consistency amongst the items representing the dieting factor, and a much lower level for those representing the bulimia factor. The results could justify the continued use of the EAT as a valid screening instrument for some aspects of eating morbidity, i.e. dieting and concern about weight and shape in non-Western populations. The analysis clearly suggested that another scale is required for bulimic behaviours.

Binge eating in the obese

This review will first describe problems in the definition of the term binge eating, especially in the absence of purging (vomiting, laxative abuse). We highlight current approaches in the classification of obesity, and then provide an overview of the available literature on differences between obese binge eaters and obese non-binge eaters. Many studies indicate that binge eating is common among the female obese, with a frequency ranging from 23 to 46% among those seeking treatment for weight reduction. Despite differences in the definitions of binge eating and variability among the samples investigated, there is strong evidence that binge eaters represent a distinct subgroup among the obese. Binge eating obese exhibit significantly more eating and weight-related pathology, as well as more psychopathology compared to their non-binge eating obese counterparts.

Binge eating in overweight women

Data on the prevalence and characteristics of binge eating in a series of 64 obese women participating in a controlled weight-reduction program are presented. Twenty-two (34.4%) reported recurrent binge eating episodes defined as overeating plus loss of control as assessed by patients' self-report and confirmed by a clinical interview. Six of those indicated that they engaged in either self-induced vomiting or laxative use to control their weight, but only two met full criteria for current bulimia nervosa according to DSM-III-R. A detailed description of the binge eating behavior revealed similarities to the eating pattern described in patients with bulimia nervosa: obese binge eaters tended to overeat in the evening, when they were alone and at home. Compared with their non-binge eating counterparts, binge eaters were significantly younger when they presented for treatment. The prevalence of childhood obesity was higher, and they were significantly younger when they first started on a diet than the non-binge eaters. Binge eaters reported more psychological problems such as body image distortion, and there was a slight tendency for binge eaters to exhibit more depressive symptomatology at baseline. No association between binge eating and weight at baseline, or weight loss during therapy or at follow-up could be found. Fluvoxamine (100 mg) did not seem to be of specific benefit in this subgroup of the obese with regard to weight loss.

Binge eating among the obese: a descriptive study

Nineteen obese females applying for treatment for binge eating were administered a semistructured interview assessing the presence or absence of food restrictions, thoughts, feelings and physical sensations associated with binges, typical precipitants to binges, and factors identified as useful in avoiding binge eating. Both negative mood and abstinence violations emerged as important precipitants. The results also suggested that these precipitants constitute separate, independent pathways to binge eating. Implications of these findings with respect to restraint theory are discussed.

No counterregulation after breaking the external restraint of children

At the present, it is unknown how restraint and binge eating/counterregulation are exactly related. Earlier studies on this relationship suffer from two main shortcomings: the studies are all correlational in nature or could not rule out the contribution of confounding variables such as weight loss. The present study investigated whether a break of restraint is a sufficient condition for the occurrence of counterregulation by studying a restrained sample which is not liable to dieting practices and weight loss. The externally imposed restraint on children with regard to eating sweets was broken. However, after breaking their external restraint the children did not counterregulate. It is discussed whether restraint of food intake is really as important for binge eating as it is claimed to be or whether it is merely a consequence or an epiphenomenon of binge eating.

Physiological effects of dieting and bingeing in rats

Female rats were assigned to dietary conditions as follows for 3.5 months: 1) Low-fat control (LFC); 2) Moderately high-fat control (HFC); 3) Alternation between restricted access to a low-fat diet and ad lib access to a very high fat diet (RA); 4) Unrestricted access to the same diets as RA (URA). Results indicate that: 1) HFC consumed the same energy as LFC, but showed a tendency to become heavier and fatter through greater food efficiency. 2) URA and LFC did not differ in body weight, food intake, body composition or energy efficiency. 3) Intake of the very high fat diet declined over time in the RA. 4) RA ate less total calories, weighed less than all other groups, and showed a tendency for decreased percentage body fat and increased percentage of weight gained due to FFM gained. Results provide no evidence that dieting and bingeing promote obesity or increased preference for dietary fat, and suggest that dietary restriction has greater impact on energy balance and body composition than does alternation of diet composition.

Dietary restraint and disinhibition: is restraint a homogeneous construct?

The homogeneity of the restraint construct is investigated in a study of 54,525 subjects participating in a weight reduction program. Using the German version of the TFEQ (Stunkard & Messick, 1985, Journal of Psychosomatic Research, 29, 71-83; Pudel & Westenhoefer 1989a, Fragebogen zum Essverhalten; Handanweisung), it is shown that different types of relations exist between the items measuring dietary restraint and the disinhibition scale. A discriminant analysis in a subgroup of moderately highly restrained eaters with either low or high disinhibition (n = 1759) reveals different sets of restraint behaviours and cognitions that differentiate between high and low disinhibition. These findings are replicated in an independent validation sample (n = 1693). Two restraint subscales are constructed, one associated with increasing disinhibition, the other with decreasing disinhibition. It is argued that different sets of restrained behaviours and cognitions should be differentiated when looking at the causal link between restraint and disturbances of eating behaviour.

A longitudinal evaluation of dietary restraint and its relationship to changes in body weight

The purpose of this investigation was to evaluate the impact of changes in dietary restraint (chronic dieting) on changes in body weight over time. Subjects were 305 (98 male, 207 female) adults. At pretest, subjects completed a restrained eating questionnaire (Herman & Polivy, 1980), as well as reporting height, weight, gender, race, and age. Subjects were recontacted 2 1/2 years later and were reassessed on these same variables. Results indicated that restrained eating scores showed a high degree of consistency over a 2-1/2-year period (intraclass correlation = .74). Over time, males gained more weight than females and normal-weight subjects gained more weight over time than overweight subjects. No relationship was found between dietary restraint and weight gain over time. The potential interactions between energy balance and body weight are discussed.

From dietary restraint to binge eating: some theoretical considerations

A correlation between dietary restraint and the occurrence of binge eating has been convincingly shown in several investigations. However, the mediating mechanisms have not yet been elaborated in detail nor linked to empirical evidence. This theoretical gap is addressed in the following. After a short review of behavioral and metabolic correlates of dietary restraint, potential effects of restrained eating on the psychophysiological regulation of food intake are described. These effects may lead to the disruption of intake regulation and therefore can be regarded as direct causes of binge eating.

Clinical and non-clinical binges

A study was conducted to determine if, and in what respects, clinical binges (reported by bulimic subjects) are different from non-clinical binges (reported by a non-clinical population). Furthermore, the study tested whether the DSM-III-R criteria and other variables that are retrospectively claimed to be defining characteristics indeed differentiate binges from non-binge eating episodes. Clinical binges appeared to differ from non-clinical binges as to amount of calories ingested and duration. With respect to subjective experience, clinical and non-clinical binges did not differ. The DSM-III-R criteria for binge eating discriminate clinical and non-clinical binges quite well from non-binges. With the addition of other seemingly important variables, binges are not discriminated better from non-binges than with the DSM-III-R variables alone. It is argued that the difference between pathological binge eating and non-clinical binge eating is mainly a matter of severity.

Adolescent concerns about weight and eating; a social-development perspective

Eight hundred and forty-six children from multi-cultural schools in neighbourhoods of differing socio-economic background were interviewed concerning their attitudes to weight and eating. The results suggested that weight concern was high in the girls, with more than 50% feeling too fat and wanting to lose weight. The levels of weight concern were almost as high in the 11 year olds as in the 18 year olds, which suggests that weight concerns are beginning earlier than in the past. White girls reported more concern than black or Asian girls. Girls from higher SES background schools showed more concern than those from lower SES schools, although they were actually slimmer. Dieting was also more common in the girls and especially so in white girls and in those from the higher SES schools. However, it was not as common as has been found in North American samples. Within the field of psychological problems these results are unusual in finding evidence for less difficulty in the children from the least socially and culturally privileged backgrounds.

Behavioral and biological correlates of dietary restraint in normal life

Based on laboratory results, restrained eating has been linked to the development of binge eating and eating disorder syndromes such as bulimia nervosa. This study was designed to extend the scope of investigation of the concept of restrained eating beyond the laboratory. Eating behavior and biochemical indices of nutritional state were investigated in 60 young women, who were divided in restrained and unrestrained eaters by questionnaire. Seven-day records of food intake showed that the high-restraint group ate around 400 kcal a day fewer than the low-restraint group. Group differences in actual macronutrient intake and long-term food preferences pointed to a qualitatively altered eating pattern in restrained eaters. Actual protein portion was higher in restrained eaters. They tried to avoid calorie dense food items of high carbohydrate and fat content. Instead, they preferred food regarded as low-caloric and healthy. Plasma levels of triiodothyronine and glucose, which could be taken as indices of long-term adaptation to starvation, were not decreased in the high-restraint group. However, significantly higher levels of triglycerides in restrained eaters may reflect a biological state due to short-term starvation. The results indicate that the concept of dietary restraint predicts eating behavior not only under experimental conditions, but also in normal life. As a consequence of altered eating patterns, psychological and physiological deprivation can be hypothesized in restrained eaters, making them prone to the occurrence of overeating.

Breakdown of dietary restraint following mere exposure to food stimuli: interrelationships between restraint, hunger, salivation, and food intake

It was hypothesised that the hunger-enhancing effects of exposure to the sight and smell of palatable food would disinhibit eating in restrained eaters (self-reported dieters). In two experiments exposure to palatable food stimuli led to increases in motivational (hunger) ratings and salivation, and was followed by overeating in restrained subjects compared with the control condition (no food during exposure) and a condition in which nonpreferred food was presented during the exposure phase. The food intake of unrestrained subjects, on the other hand, was reduced following exposure to palatable food in the first experiment. This shows that breakdown of dietary restraint can be induced by food stimuli even when the food does not constitute a preload. Mere exposure to the sight and smell of palatable food is sufficient to precipitate loss of dieting motivation. The effects of exposure on hunger and salivation were, in general, unrelated to food intake or degree of dietary restraint. Therefore, changes in hunger do not appear to directly mediate increased food intake in dieters. Instead, it is tentatively suggested that anxiety resulting from exposure to liked food may play a role both in disinhibiting eating and suppressing salivation in restrained subjects.

Eating disorders in a general practice population. Prevalence, characteristics and follow-up at 12 to 18 months

Attenders to four South London group general practices were screened using the Eating Attitudes Test (EAT), after which all high scorers and a random selection of low scorers were approached for interview. General practitioners (GPs) were given details on a random half of high-scoring patients with the aim of assessing intervention for revealed and hidden psychopathology. Twelve to 18 months later all high scorers on the EAT were followed up by post to measure change in behaviour and attitudes. Practice records were examined to determine the doctor's knowledge of the patient and any intervention that had occurred. It was found that 1.1% of women had bulimia nervosa and 2.8% a partial-syndrome eating disorder. No cases of anorexia nervosa were found. Cases of bulimia nervosa and partial syndromes were similar in being: mainly female, of higher social class, in the normal weight range but with considerable weight fluctuation in the past, more likely to have had a history of menstrual irregularity, and frequently psychologically troubled with more past psychiatric contact. Over the follow-up period there was some change along a spectrum of normal dieting to the full syndrome, although only one subject with bulimia nervosa recovered significantly. Although the GPs were unaware of the eating pathology and their intervention was minimal, most had documented their patients' psychological distress.

A cognitive behavioural group approach for the treatment of bulimia nervosa--a preliminary study

A group treatment for bulimia nervosa based on a cognitive behavioural approach is described. Eight women with a self reported average of 14 binging episodes per week attended a weekly group for 15 weeks. The techniques used in the group are described. Outcome measures included self reported frequency of binging episodes, eating attitudes, depression and anxiety. These were assessed both pre and post treatment. In addition binge frequency was assessed at 3 and 6 month follow up. Binging frequency decreased over the treatment period to an average of 1.1 per week and of 1.9 per week at 6 month follow up. Significant changes in eating attitudes, and a reduction in depression and anxiety were obtained over the treatment period. Although this study was not controlled it may represent a promising step towards the development of a cost-effective treatment for this common condition.

Innovative treatment approaches to bulimia nervosa

The available evidence indicates that behavioral interventions for bulimia nervosa are effective in many cases; yet a significant proportion of patients are not symptom-free and others relapse following termination of treatment. Explanations for the nonresponsiveness to behavioral treatment and relapse are offered, including characteristics of certain patients and the scope and implementation of behavioral interventions. The conceptual basis and therapeutic implementation of two alternate behavioral interventions, namely, temptation with exposure and response prevention (TERP) and implosive therapy (IT), are presented and reviewed for their potential utility in nonresponsive and relapsing cases.

A self-rating scale for bulimia. The 'BITE'

A new brief questionnaire, the Bulimic Investigatory Test, Edinburgh (BITE), for the detection and description of binge-eating is described. Data from two separate populations demonstrate satisfactory reliability and validity. The scale has measures of both symptoms and severity. All items in the DSM-III definition of bulimia and Russell's definition of bulimia nervosa are covered but the questionnaire is more than just an operationalised checklist of these diagnostic criteria.

Correlates of eating related difficulties among college students: a preliminary investigation

In this preliminary correlational study, sex, dieting, and rigorous eating were compared to three types of eating related difficulties (binge eating, general symptoms of anorexia nervosa, and more specific obsessions about food and weight). As predicted, significant correlations were obtained between being female, dieting, and more rigorous styles of eating and scoring higher on measures of these eating related difficulties. In addition, there were significant correlations between predictor variables. Females reported more dieting and more rigorous eating. Dieting and rigorous eating also were somewhat related. When extent of dieting and rigorous eating was controlled, the association between being female and scoring higher on these measures was somewhat reduced. The association between being female and binge eating no longer retained significance.

Physical and psychological characteristics of five male bulimics

The case histories of five men who met DSM-III criteria for bulimia and details of their physical characteristics are given. Various eating disorder questionnaires were administered and the results indicated that most of these instruments would not have identified the men as suffering from an eating disorder. The necessity of caution in asserting the prevalence of bulimia using these measures is emphasised.

Eating style: a validation study of the Dutch Eating Behaviour Questionnaire in normal subjects and women with eating disorders

This study is a validation of the Dutch Eating Behaviour Questionnaire (DEBQ). Results from normal men and women confirmed the presence of three robust factors of restraint, emotional eating and external eating. Data from women attending 'weightwatchers', and patients with diagnoses of anorexia nervosa and bulimia indicated that the DEBQ was largely successful in identifying the eating styles which are thought to characterise these three client groups. The results were also evaluated in the light of predictions from restraint theory which suggest that chronic restraint is causally related to higher levels of externality and emotional eating.