Nutrient intake of obese female binge eaters

Evaluating dietary restriction as a maintaining factor in binge-eating disorder

OBJECTIVE

Prominent theories of binge-eating (BE) maintenance highlight dietary restriction as a key precipitant of BE episodes. Consequently, treatment approaches for eating disorders (including binge-eating disorder; BED) seek to reduce dietary restriction in order to improve BE symptoms. The present study tested the hypothesis that dietary restriction promotes BE among 112 individuals with BED.

METHODS

Participants completed a 7-day ecological momentary assessment (EMA) protocol before and after completing 17 weeks of either Integrative Cognitive-Affective Therapy or guided self-help cognitive behavioral therapy. Analyses examined whether dietary restriction on 1 day of the baseline EMA protocol predicted risk for BE later that same day, and on the following day. Changes in dietary restriction over the course of treatment were also evaluated as a predictor of change in BE from pre-treatment to post-treatment. Baseline dietary restraint was examined as a moderator of the above associations.

RESULTS

Dietary restriction did not predict BE later the same day, and changes in restriction were not related to changes in BE across treatment, regardless of baseline dietary restraint levels. Restriction on 1 day did predict increased BE risk on the following day for individuals with higher levels of dietary restraint, but not those with lower levels.

DISCUSSION

These findings challenge the assumption that dietary restriction maintains BE among all individuals with BED. Rather, results suggest that dietary restriction may be largely unrelated to BE maintenance in this population, and that reducing dietary restriction generally does not have the intended effect on BE frequency.

Characterizing naturalistic meal timing, energy intake, and macronutrient intake among individuals with loss of control eating

Binge eating demonstrates an evening diurnal shift among individuals with eating disorders. Disruptions to diurnal appetitive rhythms may be somewhat chronic and set the stage for additional disruptions to prompt binge eating. Despite known diurnal shifts in binge eating and related constructs (e.g., mood) and detailed characterizations of binge-eating episodes, no findings to date describe the naturalistic diurnal timing and composition of energy and nutrient intake on days with and without loss of control eating. We aimed to characterize eating behaviors (i.e., meal timing, energy intake, and macronutrient composition) across seven days in individuals with binge-spectrum eating disorders, assessing differences between eating episodes and days with and without loss of control eating. Undergraduate students (N = 51; 76.5% female) who endorsed past 28-day loss of control eating completed a 7-day naturalistic ecological momentary assessment protocol. Participants completed daily food diaries and reported instances of loss of control eating across the 7-day period. Results indicated that episodes of loss of control were more likely to occur later in the day, but overall meal timing did not differ across days with and without loss of control. Similarly, greater caloric consumption was more likely for episodes with loss of control, but overall caloric consumption did not differ between days with and without loss of control. Analysis of nutritional content demonstrated differences between both episodes and days with and without loss of control for carbohydrates and total fats, but not for protein. Findings provide support for the hypothesized role disruptions in diurnal appetitive rhythms play in maintaining binge eating via consistent irregularities, underscoring the importance of examining treatment adjuncts that intervene on the regulation of meal timing to enhance eating disorder treatment outcomes.

Intake and adherence to energy and nutrient recommendations among women and men with binge-type eating disorders and healthy controls

BACKGROUND & AIMS

Research quantifying dietary intake in individuals with bulimia nervosa and binge-eating disorder (i.e., binge-type eating disorders) is surprisingly scant. We assessed the dietary intake of women and men with binge-type eating disorders in a large case-control study and compared them with healthy controls. We also evaluated the extent to which their dietary intake adhered to the Nordic Nutrition Recommendations. Among cases, we assessed the relationship of binge eating frequency with energy and macronutrient intake.

METHODS

We derived the total daily energy, macro-, and micronutrient intake of 430 cases with binge-type eating disorders (women: n = 391, men: n = 39) and 1227 frequency-matched controls (women: n = 1,213, men: n = 14) who completed the MiniMeal-Q, a validated food frequency questionnaire. We calculated mean intake for men and women and, in women, compared mean intake of energy and nutrients between cases and controls using linear regression. We calculated the proportion of women and men who met the recommended intake levels from the NNR, and compared these proportions in female cases and controls using logistic regression. We used linear regression to examine energy and macronutrient intake of women with varying frequencies of current binge-eating.

RESULTS

Female, but not male cases, had a higher mean intake of total energy/day compared with controls and higher intake than recommended. The majority in all groups (male and female cases and controls) exceeded saturated fat recommendations, and did not meet recommendations for omega-3 fatty acid intake. Among all groups, adherence was low for vitamin D, selenium, and salt. Iron and folate intake was low among the majority of women, especially controls. Female cases with ≥4 binge-eating episodes in the past 28 days had higher intake of energy and percent carbohydrates, and lower intake of percent fat, compared to cases with no binge-eating episodes in the past month.

CONCLUSIONS

Higher than recommended total daily energy intake among women with binge-type eating disorders may lead to weight gain and downstream health complications, if persistent. In most women, iron and folate intake was insufficient, which may have negative consequences for reproductive health. We found suboptimal adherence for key nutrients that are important to limit (saturated fat and salt) or meet (omega-3 fatty acids) for cardiovascular and overall health in all groups. Nutrition counseling should form an important pillar of treatment to assist with normalization of eating patterns and may also benefit individuals without eating disorders to optimize nutrient intake for long term health promotion.

The Complicated Relationship between Dieting, Dietary Restraint, Caloric Restriction, and Eating Disorders: Is a Shift in Public Health Messaging Warranted?

The origins of theories specifying dietary restraint as a cause of eating disorders can be traced to the 1970s. This paper will present an overview of the origins of dietary restraint theories and a brief historical review of evidence will be summarized. Recent research will be presented, including the results from the CALERIE Phase 1 study, as well as CALERIE Phase 2, which were NIH-sponsored randomized controlled trials. CALERIE 2 provided a test of the effect of two years of caloric restriction (CR) on the development of eating disorder syndromes and symptoms in comparison to a control group that did not alter eating behavior or body weight. The intervention was effective for inducing a chronic (two-year) reduction in total energy expenditure and increased dietary restraint but did not increase symptoms of eating disorders. The results of this recent investigation and other studies have not provided experimental support for conventional dietary restraint theories of eating disorders. These findings are discussed in terms of potential revisions of dietary restraint theory, as well as the implications for a paradigm shift in public health messaging related to dieting.

The food restriction wars: Proposed resolution of a primary battle

Research regarding the definition and consequences of dieting has generated controversy for years. This controversy has spilled over into the public domain, especially as eating disorders and obesity have become more prevalent. One of the earliest and longest-lasting controversies involves the restrained eating framework, which was originally developed by Herman and Polivy and also strongly influenced the development of the cognitive-behavioral model of bulimia nervosa. An alternative framework for understanding the role of dieting in nonclinical and clinical groups, called the Three-Factor Model of Dieting, took a sharply different approach to defining, and understanding the impact of, dieting. This paper provides a brief historical review of the development of these divergent perspectives and updates the Three Factor Model's critical distinction between restraining eating to prevent over-consumption and dieting to lose weight. We suggest that three historical trends impacted the development of Restraint Theory in ways that unfairly impugned dieting for weight control: the emergence of the new eating disorders of bulimia nervosa and binge eating disorder, a population-based increase in loss of control eating and a population-based increase in obesity. This update is aimed in part at encouraging new research to reconcile ongoing, unresolved issues between Herman and Polivy's restrained eating model and the Three-Factor model of Dieting model. Such research might also contribute to the public's understanding of the pros and cons of dieting and to new approaches to treating eating disorders and obesity.

Dietary restraint and weight loss as risk factors for eating pathology

Measures of dietary restraint do not consistently predict caloric restriction, and these scales appear inadequate for differentiating between healthy and risky restraint in individuals. The current study examined the relationship between self-reported dietary restraint, recent weight loss, body mass index (BMI), and eating pathology in a college sample to determine if dietary restraint coupled with caloric restriction would prove to be a more sensitive marker of eating disorder risk than restraint alone. Participants (N=245) completed a series of measures evaluating dietary restraint, recent weight loss, and eating habits. Results suggested that dietary restraint related most consistently to eating pathology, with more nuanced results for women regarding the relations between dietary restraint, recent weight loss, and BMI. Findings provided further evidence that dietary restraint and weight loss may relate to eating pathology through independent pathways. In addition, recent weight loss may be a relevant risk factor for women at lower current BMI.

Motivational dynamics underlying eating regulation in young and adult female dieters: relationships with healthy eating behaviours and disordered eating symptoms

OBJECTIVE

To investigate whether type of goals and motives underlying females' eating regulation are associated differentially with daily eating behaviours, dependent upon weight and age category.

DESIGN

99 late adolescent female dieters (Mage = 18.94) and 98 adult female dieters (Mage = 45.06), 23.6% of which were overweight, completed a questionnaire and a 7-day diary assessment. Descriptive analysis and path analysis were performed to investigate the research questions.

MAIN OUTCOME MEASURES

Healthy eating behaviours (HEHS), drive for thinness and binge eating symptoms (EDI).

RESULTS

Appearance-focused and controlled eating regulation were positively related to disordered eating symptoms throughout the week. In contrast, autonomous and health-focused eating regulation were associated positively with healthy eating behaviours and were either related negatively or unrelated to disordered eating symptoms. Mean level differences in motivation and eating behaviours emerged according to age and weight status. However, the examined structural model was similar for late adolescent and adult dieters and only few differences emerged between normal-weight and overweight dieters.

CONCLUSION

Dieters' type of motivation helps to explain when eating regulation relates to healthy and disordered eating symptoms.

Retrospective Correlates for Bulimia Nervosa: A Matched Case-Control Study

OBJECTIVE

There have been few studies investigating the risk factors for bulimia nervosa (BN), and most have been in Anglo-Saxon countries. This study aimed to (i) replicate the uncontested retrospective correlates for BN and clarify the role of factors with inconsistent findings and (ii) evaluate the strength of these factors in a different culture.

METHOD

A case-control design was used to compare 60 women who met the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for BN to 60 healthy controls and 60 participants with other psychiatric disorders. Retrospective correlates were assessed by interviewing each person with the Oxford Risk Factor Interview.

RESULTS

The primary retrospective correlates identified from the comparison of BN participants to healthy controls were general high maternal expectations, negative attitudes about parental weight and obesity in childhood and adolescence. Compared with participants with other psychiatric disorders, those with BN also reported higher rates of childhood obesity, deliberate self-harm, family conflicts, general high maternal expectations and feeling fat in childhood.

CONCLUSIONS

The common findings across cultures suggest that, at least, individuals subjectively experience a number of similar factors that increase risk for developing BN. In addition, the difference regarding self-harm is notable.

Effectiveness of lifestyle interventions to reduce binge eating symptoms in African American and Hispanic women

OBJECTIVE

Lifestyle interventions that promote physical activity and healthy dietary habits may reduce binge eating symptoms and be more feasible and sustainable among ethnic minority women, who are less likely to seek clinical treatment for eating disorders. The purpose of this study was to investigate (1) whether participating in a lifestyle intervention is a feasible way to decrease binge eating symptoms (BES) and (2) whether changes in BES differed by intervention (physical activity vs. dietary habits) and binge eating status at baseline (binger eater vs. non-binge eater) in African American and Hispanic women.

METHOD

Health Is Power (HIP) was a longitudinal randomized controlled trial to promote physical activity and improve dietary habits. Women (N = 180) who completed anthropometric measures and questionnaires assessing fruit and vegetable and dietary fat intake, BES and demographics at baseline and post-intervention six months later were included in the current study.

RESULTS

Over one-fourth (27.8%) of participants were categorized as binge-eaters. Repeated measures ANOVA demonstrated significant two- and three-way interactions. Decreases in BES over time were greater in binge eaters than in non-binge eaters (F(1,164) = 33.253, p < .001), and women classified as binge eaters who participated in the physical activity intervention reported greater decreases in BES than non-binge eaters in the dietary habits intervention (F(1,157) = 5.170, p = .024).

DISCUSSION

Findings suggest behavioral interventions to increase physical activity may lead to reductions in BES among ethnic minority women and ultimately reduce the prevalence of binge eating disorder and health disparities in this population.

Prevalence of screening-detected eating disorders in chinese females and exploratory associations with dietary practices

OBJECTIVE

China is undergoing dramatic Westernization, hence may be able to provide unique insights into the role of sociocultural factors in disease. The purpose of this exploratory study was two-fold: to describe the prevalence of screening-detected eating disorders and disordered eating in China at the first occasion of assessment in the large-scale China Health and Nutrition Survey (CHNS) and to explore the associations between dietary practices and disordered eating. Regarding the first objective, participants are provincially representative and in subsequent waves will be followed longitudinally.

METHOD

CHNS participants were recruited using multistage, cluster random sampling, beginning in 1989. In this study, participants comprised 259 female adolescents (12-17 years) and 979 women (18-35 years) who participated in the CHNS 2009 survey, which is the first CHNS survey to assess disordered eating. Dietary practice-disordered eating associations were investigated with logistic regression adjusting for age, body mass index, and urbanization.

RESULTS

Of the participants, 6.3% (95% CI: 4.8, 8.2) of adults and 7.8% (95% CI: 5.0, 12.0) of adolescents had a screening-detected eating disorder. Dietary practices had non-significant associations with disordered eating at the general population level, except for protein consumption among women. There was evidence that skipping meals and a high-fat diet may confer risk.

DISCUSSION

Screening-detected eating disorders in China are lower in prevalence than in developed countries. Dietary practices had fairly limited associations with disordered eating at the general population level; protein consumption, skipping meals, and a high-fat diet are candidate dietary practice exposures for disordered eating. Copyright © 2014 John Wiley & Sons, Ltd and Eating Disorders Association.

The association of binge eating and neighbourhood fast-food restaurant availability on diet and weight status

OBJECTIVE

Fast-food restaurants (FFR) are prevalent. Binge eating is common among overweight and obese women. For women prone to binge eating, neighbourhood FFR availability (i.e. the neighbourhood around one's home) may promote poor diet and overweight/obesity. The present study tested the effects of binge eating and neighbourhood FFR availability on diet (fat and total energy intake) and BMI among African American and Hispanic/Latino women.

DESIGN

All measures represent baseline data from the Health is Power randomized clinical trial. The numbers of FFR in participants' neighbourhoods were counted and dichotomized (0 or ≥1 neighbourhood FFR). Participants completed measures of binge eating status and diet. Weight and height were measured and BMI calculated. 2 (binge eating status) × 2 (neighbourhood FFR availability) ANCOVA tested effects on diet and BMI while controlling for demographics.

SETTING

Houston and Austin, TX, USA.

SUBJECTS

African American and Hispanic/Latino women aged 25-60 years.

RESULTS

Of the total sample (n 162), 48 % had 1-15 neighbourhood FFR and 29 % were binge eaters. There was an interaction effect on BMI (P = 0·05). Binge eaters with ≥1 neighbourhood FFR had higher BMI than non-binge eaters or binge eaters with no neighbourhood FFR. There were no significant interactions or neighbourhood FFR main effects on total energy or fat intake (P > 0·05). A main effect of binge eating showed that binge eaters consumed more total energy (P = 0·005) and fat (P = 0·005) than non-binge eaters.

CONCLUSIONS

Binge eaters represented a substantial proportion of this predominantly overweight and obese sample of African American and Hispanic/Latino women. The association between neighbourhood FFR availability and weight status is complicated by binge eating status, which is related to diet.

Underreporting in obese inpatients undergoing a psycho-nutritional rehabilitative program

OBJECTIVE

To evaluate the possible correlation between underreporting and anthropometric, psychological and socio-anagraphic characteristics in obese inpatients.

DESIGN

Perspective longitudinal study.

SUBJECTS

Forty-two obese inpatients enrolled to a multidisciplinary 3-week weight loss program in a psycho-nutritional rehabilitative structure located in Salice Terme, Northern Italy. They underwent anthropometric, dietary, clinical, and psycho diagnostic evaluation.

RESULTS

Forty-two subjects were included in the study of which 29 (70 %) were females and 13 were males. Mean BMI and mean waist circumference were 42.7 ± 9.5 kg/m(2) and 125 ± 18 cm, respectively. The mean weight loss of 4.2 ± 2.2 kg in the whole sample was significantly greater in males compared to females. The waist circumference fell in equal measure in both of the sexes. Thirty patients were classified as underreporters according to Goldberg, two-thirds of which were females. In the course of the three recovery weeks, a third of the 30 subjects identified as underreporters at the beginning continued to underreport energy intake.

CONCLUSION

In our study, the prevalence of underreporting was equal to over 70 % of the original sample. There was no significant difference between the weight losses achieved by the underreporter and non-underreporter groups. All the underreporters initially became partly non-underreporters during treatment. Those who gave up the practice of underreporting were patients who had a more elevated BMI, who were more susceptible to binge eating behavior and who experienced a strong uneasiness both physically and psychologically. They also had a strongly impaired quality of life.

Double trouble: restrained eaters do not eat less and feel worse

OBJECTIVE

While high levels of dietary restraint do not appear to reflect actual caloric restraint, it has been found to be a risk factor for a wide array of maladaptive eating patterns. These findings raise the question what, if not caloric restriction, dietary restraint entails. We propose that the very finding that restrained eaters do not eat less than they intend to do can provide an answer. Based on this disparity between the intention to restrain oneself and actual behaviour, we therefore hypothesised that high levels of restraint are associated with eating-related guilt.

METHOD

Three studies (N = 148) using unobtrusive measures of food intake; different restraint scales; and different measures of guilt tested whether restraint is related to eating-related guilt.

RESULTS

Results indicated that restraint was not associated with food intake, but instead was associated with increased levels of guilt after eating. Guilt was explicitly related to food intake. Moreover, the observed guilt could not be attributed to a general increase in negative affect.

CONCLUSION

The results of these studies suggest that restraint is not an indicator of actual restricted food intake, but rather a reflection concerns about food and eating manifested in eating-related guilt.

Caloric deprivation increases responsivity of attention and reward brain regions to intake, anticipated intake, and images of palatable foods

Dietary restraint theoretically increases risk for binge eating, but prospective and experimental studies have produced contradictory findings, apparently because dietary restraint scales do not identify individuals who are reducing caloric intake. Yet, experimentally manipulated caloric deprivation increases responsivity of brain regions implicated in attention and reward to food images, which may contribute to binge eating. We tested whether self-imposed acute and longer-term caloric restriction increases responsivity of attention and reward regions to images, anticipated receipt, and receipt of palatable food using functional magnetic resonance imaging among female and male adolescents (Study 1 n=34; Study 2 n=51/81). Duration of acute caloric deprivation correlated positively with activation in regions implicated in attention, reward, and motivation in response to images, anticipated receipt, and receipt of palatable food (e.g., anterior cingulate cortex, orbitofrontal cortex, putamen, and precentral gyrus respectively). Youth in a longer-term negative energy balance likewise showed greater activation in attention (anterior cingulate cortex, ventral medial prefrontal cortex), visual processing (superior visual cortex), reward (caudate) and memory (hippocampus) regions in response to receipt and anticipated receipt of palatable food relative to those in neutral or positive energy balance. Results confirm that self-imposed caloric deprivation increases responsivity of attention, reward, and motivation regions to food, which may explain why caloric deprivation weight loss diets typically do not produce lasting weight loss.

Relationship of fruit, vegetable, and fat consumption to binge eating symptoms in African American and Hispanic or Latina women

African American (AA) and Hispanic or Latina (HL) women have the highest rates of overweight and obesity of any gender and ethnic groups. Binge eating disorder (BED) is the most common eating disorder in the United States and is linked to overweight and obesity. Traditional treatments for BED may not be appropriate or viable for AA and HL women, because they are less likely than whites to seek treatment for psychological conditions and may have less access to healthcare. Improving dietary habits in those with BED or subthreshold BED may reduce binge eating symptoms. The current study investigated the association of fruit, vegetable, and fat consumption to binge eating symptoms in AA and HL women. AA and HL women in the Health Is Power (HIP) study (N=283) reported fruit and vegetable intake, fat intake, and binge eating symptoms. Women were middle aged (M=45.8 years, SD=9.2) and obese (M BMI=34.5 kg/m(2), SD=7.5). Greater fat consumption was correlated with lower fruit and vegetable consumption (r(s)=-0.159, p<0.01). Higher BMI (r(s)=0.209, p<0.01), and greater fat consumption (r(s)=0.227, p<0.05) were correlated with increased binge eating symptoms. Multiple regression analysis demonstrated that for HL women (β=0.130, p=0.024), higher BMI (β=0.148, p=0.012), and greater fat consumption (β=0.196, p=0.001) were associated with increased binge eating symptoms (R(2)=0.086, F(3,278)=8.715, p<0.001). Findings suggest there may be a relationship between fat consumption and binge eating symptoms, warranting further study to determine whether improving dietary habits may serve as a treatment for BED in AA and HL women.

Behavioural interventions for obese adults with additional risk factors for morbidity: systematic review of effects on behaviour, weight and disease risk factors

BACKGROUND

Reducing obesity through effective behaviour change interventions is of key importance to prevent disabling and life-threatening conditions, particularly in individuals already at risk for morbidity.

PURPOSE

To assess the effects of behavioural interventions for obese adults with additional risk factors for morbidity on behaviour, weight and disease risk factors.

METHODS

Systematic review of randomised controlled trials (RCTs). Three electronic databases and three journals were searched for behavioural interventions (aimed at changing dietary intake and/or physical activity (PA)) for adults (mean BMI ≥30 kg/m(2); mean age ≥40 years) with risk factors for morbidity, reporting follow-up data ≥12 weeks.

RESULTS

44 RCTs met the inclusion criteria. Behavioural outcomes, weight loss, and cardiovascular disease risk factors showed consistent modest improvements over time, especially for interventions targeting both diet and PA.

CONCLUSION

Behavioural interventions in at-risk populations showed positive effect tendencies on behaviour, weight, and disease risk factors. However, there is still ample room for improvement, and future research should focus on identifying the most effective means of inducing dietary and PA behaviour change in this vulnerable population.

Relation of dietary restraint scores to cognitive biases and reward sensitivity

This study tested the hypotheses that dietary restraint scores are associated with greater reward sensitivity and cognitive bias for food-related cues, which might result in chronic overeating and efforts to curb this tendency through dietary restriction. Participants (N=63) with high versus low scores on the DEBQ-R did not differ on attentional bias for pictorial food-related cues on a visual probe task, or approach tendencies elicited by food cues, as assessed with a stimulus-response compatibility (SRC) task. Restraint was also unrelated to performance on an operant task that assessed how hard participants would work for snacks, or responding during a taste habituation paradigm. Dietary restraint scores were correlated with self-reported appetitive response to food, sensitivity to reward, and sensitivity to punishment. Results provide limited support for the hypothesis that individuals with elevated dietary restraint scores show greater reward sensitivity and cognitive bias for food stimuli, though it is possible that the null findings on the behavioral task resulted because of an approach-avoidance conflict to food cues in which heightened appetitive responses to food are inhibited by food-related anxiety.

Risk factors and prodromal eating pathology

Prospective studies have identified factors that increase risk for eating pathology onset, including perceived pressure for thinness, thin-ideal internalization, body dissatisfaction, dietary restraint, and negative affect. Research also suggests that body dissatisfaction and dietary restraint may constitute prodromal stages of the development of eating disorders. Prevention trials indicate that interventions that reduce pressure to be thin, thin-ideal internalization, body dissatisfaction, and negative affect significantly reduce eating disorder symptoms. Further, there is evidence that selective prevention programs that target young women at elevated risk for eating pathology by virtue of thin-ideal internalization, body dissatisfaction, and negative affect produce significant larger intervention effects than do universal programs offered to unselected populations. Thus, research on risk factors and prodromal stages of eating pathology has assisted in the design of efficacious prevention programs and the identification of high-risk individuals to target with these interventions; additional research in this area may lead to even more effective prevention programs.

Are dietary restraint scales valid measures of dietary restriction? Additional objective behavioral and biological data suggest not

Prospective studies find that individuals with elevated dietary restraint scores are at increased risk for bulimic symptom onset, yet experiments find that assignment to energy-deficit diet interventions reduce bulimic symptoms. One explanation for the conflicting findings is that the dietary restraint scales used in the former studies do not actually identify individuals who are restraining their caloric intake. Thus, we tested whether dietary restraint scales showed inverse relations to objectively measured caloric intake in three studies. Four dietary restraint scales did not correlate with doubly labeled water estimates of caloric intake over a 2-week period (M, r=.01). One scale showed a significant inverse correlation with objectively measured caloric intake during a regular meal ordered from an ecologically valid menu (M, r=-.30), but a significant positive relation that was qualified by a significant quadratic effect, to objectively measured caloric intake during multiple eating episodes in the lab (M, r=.32). In balance, results suggest that dietary restraint scales are not valid measures of dietary restriction, replicating findings from prior studies that examined objective measures of caloric intake.

Psychological treatments for bulimia nervosa and binging

BACKGROUND

A specific manual-based form of cognitive behavioural therapy (CBT) has been developed for the treatment of bulimia nervosa (CBT-BN) and other common related syndromes such as binge eating disorder. Other psychotherapies and modifications of CBT are also used.

OBJECTIVES

To evaluate the efficacy of CBT, CBT-BN and other psychotherapies in the treatment of adults with bulimia nervosa or related syndromes of recurrent binge eating.

SEARCH STRATEGY

Handsearch of The International Journal of Eating Disorders since first issue; database searches of MEDLINE, EXTRAMED, EMBASE, PsycInfo, CURRENT CONTENTS, LILACS, SCISEARCH, CENTRAL and the The Cochrane Collaboration Depression, Anxiety & Neurosis Controlled Trials Register; citation list searching and personal approaches to authors were used. Search date June 2007.

SELECTION CRITERIA

Randomised controlled trials of psychotherapy for adults with bulimia nervosa, binge eating disorder and/or eating disorder not otherwise specified (EDNOS) of a bulimic type which applied a standardised outcome methodology and had less than 50% drop-out rate.

DATA COLLECTION AND ANALYSIS

Data were analysed using the Review Manager software program. Relative risks were calculated for binary outcome data. Standardised mean differences were calculated for continuous variable outcome data. A random effects model was applied.

MAIN RESULTS

48 studies (n = 3054 participants) were included. The review supported the efficacy of CBT and particularly CBT-BN in the treatment of people with bulimia nervosa and also (but less strongly due to the small number of trials) related eating disorder syndromes.Other psychotherapies were also efficacious, particularly interpersonal psychotherapy in the longer-term. Self-help approaches that used highly structured CBT treatment manuals were promising. Exposure and Response Prevention did not enhance the efficacy of CBT.Psychotherapy alone is unlikely to reduce or change body weight in people with bulimia nervosa or similar eating disorders.

AUTHORS' CONCLUSIONS

There is a small body of evidence for the efficacy of CBT in bulimia nervosa and similar syndromes, but the quality of trials is very variable and sample sizes are often small. More and larger trials are needed, particularly for binge eating disorder and other EDNOS syndromes. There is a need to develop more efficacious therapies for those with both a weight and an eating disorder.

Experimental investigation of the effects of naturalistic dieting on bulimic symptoms: Moderating effects of depressive symptoms

Prospective studies suggest that dieting increases risk for bulimic symptoms, but experimental trials indicate dieting reduces bulimic symptoms. However, these experiments may be unrepresentative of real-world weight loss dieting. In addition, the fact that most dieters do not develop eating disorders suggests moderating factors may be important. Accordingly, we randomly assigned 157 female intermittent dieters to either diet as they usually do for weight loss or eat as they normally do when not dieting for 4 weeks. Naturalistic dieting halted the weight gain shown by controls, but did not result in significant weight loss. Although there was no main effect of the dieting manipulation on bulimic symptoms, moderation analyses indicated that naturalistic dieting decreased bulimic symptoms among participants with initially low depressive symptoms. Results suggest that self-initiated weight loss dieting is not particularly effective, which appears to explain several discrepancies in the literature. Additionally, depressive symptoms may be an important determinant of bulimic symptoms that eclipses the effects of naturalistic dieting on this outcome.

Measurement of dietary restraint: validity tests of four questionnaires

This study tested the validity of four measures of dietary restraint: Dutch Eating Behavior Questionnaire, Eating Inventory (EI), Revised Restraint Scale (RS), and the Current Dieting Questionnaire. Dietary restraint has been implicated as a determinant of overeating and binge eating. Conflicting findings have been attributed to different methods for measuring dietary restraint. The validity of four self-report measures of dietary restraint and dieting behavior was tested using: (1) factor analysis, (2) changes in dietary restraint in a randomized controlled trial of different methods to achieve calorie restriction, and (3) correlation of changes in dietary restraint with an objective measure of energy balance, calculated from the changes in fat mass and fat-free mass over a six-month dietary intervention. Scores from all four questionnaires, measured at baseline, formed a dietary restraint factor, but the RS also loaded on a binge eating factor. Based on change scores, the EI Restraint Scale was the only measure that correlated significantly with energy balance expressed as a percentage of energy required for weight maintenance. These findings suggest that, of the four questionnaires tested, the EI Restraint Scale was the most valid measure of the intent to diet and actual caloric restriction.

An experimental test of the effects of dieting on bulimic symptoms: The impact of eating episode frequency

Prospective studies suggest dieting increases bulimic symptoms, but experiments suggest that dieting decreases bulimic symptoms. One possible explanation for the conflicting findings is that real world dieting involves less healthy dieting techniques, such as meal skipping, than prescribed diets. We tested whether the manipulation of eating episode frequency during dieting impacted bulimic symptoms. We expected that people on a diet involving fewer eating episodes would exhibit greater increases in bulimic symptoms than people on a diet involving more frequent eating episodes or waitlist controls. Participants on both 6-week diets lost more weight than controls, confirming dieting was manipulated, and showed greater reductions in bulimic symptoms than controls; however, the dieting conditions did not differ on either outcome. Results provide further experimental evidence that dieting does not increase bulimic symptoms, but suggests that eating episode frequency has little impact on this outcome.

Psychosocial and physical impairment in overweight adolescents at high risk for eating disorders

OBJECTIVE

Many overweight adolescents display elevated risk for the development of eating disorders, as seen in higher rates of weight/shape concerns and disordered eating behaviors, but the extent of impairment in this subset of high-risk adolescents has not been explored.

RESEARCH METHODS AND PROCEDURES

Eighty-one overweight adolescents (63% girls) presenting for an Internet-based weight loss program were assessed at baseline using the Eating Disorder Examination Questionnaire, the Depression, Anxiety, and Stress Scale, and the Pediatric Quality of Life questionnaire. Adolescents who earned elevated scores on both the Weight Concern and Shape Concern subscales of the Eating Disorder Examination Questionnaire were considered at high risk for the development of eating disorders (56.8%).

RESULTS

Comparisons of high- and normal-risk groups revealed that high-risk adolescents reported higher levels of depression [F(3,76) = 5.75, p = 0.019], anxiety [F(3,76) = 5.67, p = 0.020], and stress [F(3,75) = 8.50, p = 0.005], and greater impairments in physical health [F(3,77) = 10.7, p = 0.002], emotional functioning [F(3,77) = 5.3, p = 0.024], and social functioning [F(3,77) = 10.0, p = 0.002]. There were no differences in school functioning [F(3,77) = 1.5, p = 0.219]. Among the high-risk adolescents, over half (52.2%) reported binge eating at least once in the past month.

DISCUSSION

Results suggest that overweight adolescents at high risk for the development of eating disorders also experience elevated levels of negative affect, impairment in health-related quality of life, and eating disturbances, although prospective data are needed to determine the directionality between eating disorder pathology and general psychopathology. Further research is warranted to evaluate whether behavioral weight loss interventions should be enhanced for this high-risk subset.

Relations between dietary restraint, depressive symptoms, and binge eating: A longitudinal study

OBJECTIVE

Temporal relations between dietary restraint, depressive symptoms, and binge eating were tested by means of three competing models positing that (1) dietary restraint and depressive symptoms predict future increases in binge eating, (2) binge eating predicts future increases in dietary restraint and depressive symptoms, and (3) binge eating is reciprocally related to these two factors.

METHOD

Longitudinal data from a community sample of Dutch females (N = 143; M age = 19.6) was used to test these relations while controlling for initial levels of these factors.

RESULTS

Dietary restraint did not predict future increases in binge eating, nor did binge eating predict future increases in dietary restraint. Depressive symptoms predicted future increases in binge eating, but binge eating did not predict future increases in depressive symptoms.

CONCLUSION

Although this study had limited statistical power, the pattern of relations and effect sizes suggest that depressive symptoms, but not dietary restraint, increase risk of binge eating for late adolescent females.

Relation of successful dietary restriction to change in bulimic symptoms: a prospective study of adolescent girls

Recent experimental evidence that dietary restriction results in decreased bulimic and depressive symptoms seems inconsistent with findings from prospective studies and etiologic theory. However, because the dieting manipulated in these experiments may be unrepresentative of real-world weight loss dieting, the authors tested whether successful dietary restriction was associated with decreases in these outcomes by using longitudinal data from a school-based study of 496 adolescent girls. Moderately overweight participants who evidenced successful dietary restriction showed significantly greater decreases in bulimic symptoms than weight-matched participants who did not show successful dietary restriction; however, there were no effects for depressive symptoms. In conjunction with past experimental findings, results seem to imply that successful dietary restriction curbs bulimic symptoms, suggesting that current etiologic models may need revision.

Overeating among seriously overweight children seeking treatment: results of the children's eating disorder examination

OBJECTIVE

We sought to examine rates of eating disorder symptoms among seriously overweight children seeking treatment using the Eating Disorder Examination for Children (ChEDE) and to provide initial data about their association with treatment outcome.

METHOD

Overweight children (N = 27) 8-13 years old were interviewed using the ChEDE before participating in a family-based behavioral treatment program. Height and weight were measured pretreatment, posttreatment, and approximately 8 months posttreatment.

RESULTS

Fifteen percent of children reported subjective bulimic episodes (SBE). Weight loss did not differ for children with and without SBEs, but concerns about body shape were related to larger weight losses during treatment.

CONCLUSION

A considerable minority of treatment-seeking overweight children report an episodic sense of loss of control over eating. Loss of control is related to other disordered eating attitudes and behaviors, but does not appear to affect treatment outcome. Future studies are needed to replicate these initial findings.

Evaluation of a healthy-weight treatment program for bulimia nervosa: a preliminary randomized trial

OBJECTIVE

Conduct a randomized treatment trial to test whether healthy dieting maintains bulimic symptoms or effectively reduces this eating disturbance.

METHODS

Female participants (n=85) with full- and sub-threshold bulimia nervosa were randomly assigned to a 6-session healthy dieting intervention or waitlist condition and assessed through 3-month follow-up.

RESULTS

Relative to control participants, intervention participants showed modest weight loss during treatment and demonstrated significant improvements in bulimic symptoms that persisted through follow-up.

DISCUSSION

These preliminary results suggest that this intervention shows potential for the treatment of bulimia nervosa and may be worthy of future refinement and evaluation. Results also provide experimental evidence that dieting behaviors do not maintain bulimia nervosa, suggesting the need to reconsider maintenance models for this eating disorder.

Obesity: prevalence, theories, medical consequences, management, and research directions

Obesity and its associated disorders are a growing epidemic across the world. Many genetic, physiological, and behavioral factors play a role in the etiology of obesity. Diet and exercise are known to play a valuable role in the treatment and prevention of obesity and associated disorders such as hypertension, heart disease, and diabetes. Therefore, the purpose of this review is to examine the prevalence, etiology, consequences, and treatment of obesity.

Effects of a weight maintenance diet on bulimic symptoms in adolescent girls: an experimental test of the dietary restraint theory

It is widely accepted that dieting increases the risk for bulimia nervosa, but there have been few experimental tests of this theory. The authors conducted a randomized experiment with adolescent girls (N=188) to examine the effects of a weight maintenance diet on bulimic symptoms. A manipulation check verified that the diet intervention resulted in weight maintenance and significantly reduced the risk for obesity onset and weight gain observed in assessment-only controls. As hypothesized, the diet intervention resulted in significantly greater decreases in bulimic symptoms and negative affect than observed in controls. These experimental findings, which converge with those from a weight loss diet experiment, appear antithetical to dietary restraint theory and suggest instead that dietary restriction curbs bulimic symptoms.

Categorical versus dimensional models of eating disorders: an examination of the evidence

OBJECTIVE

Eating disorders have been conceptualized as discrete syndromes or categories and as dimensions that differ in degree among individuals. Until recently, researchers have not directly addressed which of these models, categorical versus dimensional, is most valid.

METHODS

The primary objective of this review was to examine the evidence related to the validity of dimensional versus categorical models of eating disorders.

RESULTS

Findings from a series of taxometric studies have suggested that a conceptual representation of eating disorders may involve a latent taxon, related to binge eating (and possibly purging), and one or more dimensions. These studies found that binge eating was identified as a factor that does not occur on a continuum with anorexia nervosa, restricting subtype. Restricting subtype anorexia is continuous with normalcy, however.

DISCUSSION

These findings should be viewed as preliminary evidence that may have implications for the etiology, assessment, prevention, and treatment of eating disorders.

Are dietary restraint scales valid measures of acute dietary restriction? Unobtrusive observational data suggest not

The finding that dietary restraint scales predict onset of bulimic pathology has been interpreted as suggesting that dieting causes this eating disturbance, despite the dearth of evidence that these scales are valid measures of dietary restriction. The authors conducted 4 studies that tested whether dietary restraint scales were inversely correlated with unobtrusively measured caloric intake. These studies, which varied in foods consumed, settings, and populations, indicated that common dietary restraint scales were largely uncorrelated with acute caloric intake. Results suggest that these scales are not valid measures of short-term dietary restriction and imply that it may be prudent to reinterpret findings from studies thai use these scales, including those that suggest dietary restraint is a risk factor for bulimic pathology.

Eating disorder prevention programs: A meta-analytic review

This meta-analysis of eating disorder prevention programs found that intervention effects ranged from an absence of any effects to reductions in current and future eating pathology. Certain effects persisted as long as 2 years and were superior to minimal-intervention control conditions. Larger effects occurred for selected (vs. universal), interactive (vs. didactic), and multisession (vs. single session) programs; for programs offered solely to females and to participants over age 15; for programs without psychoeducational content; and for trials that used validated measures. The results identify promising prevention programs and delineate sample, format, and design features that are associated with larger effects, but they suggest the need for improved methodological rigor and statistical modeling of trials and enhanced theoretical rationale for interventions.

Psychological and dietary treatments of binge eating disorder: conceptual implications

OBJECTIVE

The authors review the available literature on psychological and dietary treatment approaches for binge eating disorder (BED).

METHODS

Studies were grouped according to psychological versus dietary approaches to BED. Studies were reviewed in terms of general implications, but particular emphasis was placed on drop-out rates, abstinence from binge eating, and weight loss.

RESULTS

Drop-out rates from psychological or dietary approaches to treatment averaged 20% and the presence of binge eating did not confer a greater risk of drop-out among obese individuals. Both psychological and dietary approaches to treatment produced abstinence rates from binge eating of approximately 50% at the 12-month follow-up. Both psychological and dietary approaches show modest efficacy of short-term weight loss, but these effects are generally not sustained in long-term follow-up assessments.

DISCUSSION

Psychological and dietary approaches to BED treatment show reasonable efficacy in binge eating reduction, but limited efficacy in weight loss. These findings are discussed in terms of the validity of the BED construct and the need for more psychopathology studies of BED.