Biological correlates of binge eating

Psychotherapy for transdiagnostic binge eating: A randomized controlled trial of cognitive-behavioural therapy, appetite-focused cognitive-behavioural therapy, and schema therapy

Cognitive-behavioural therapy (CBT) is the recommended treatment for binge eating, yet many individuals do not recover, and innovative new treatments have been called for. The current study compares traditional CBT with two augmented versions of CBT; schema therapy, which focuses on early life experiences as pivotal in the history of the eating disorder; and appetite-focused CBT, which emphasises the role of recognising and responding to appetite in binge eating. 112 women with transdiagnostic DSM-IV binge eating were randomized to the three therapies. Therapy consisted of weekly sessions for six months, followed by monthly sessions for six months. Primary outcome was the frequency of binge eating. Secondary and tertiary outcomes were other behavioural and psychological aspects of the eating disorder, and other areas of functioning. No differences among the three therapy groups were found on primary or other outcomes. Across groups, large effect sizes were found for improvement in binge eating, other eating disorder symptoms and overall functioning. Schema therapy and appetite-focused CBT are likely to be suitable alternative treatments to traditional CBT for binge eating.

Association of macrophage inhibitory cytokine-1 with nutritional status, body composition and bone mineral density in patients with anorexia nervosa: the influence of partial realimentation

Background

Macrophage inhibitory cytokine-1 (MIC-1) is a key inducer of cancer-related anorexia and weight loss. However, its possible role in the etiopathogenesis of nutritional disorders of other etiology such as anorexia nervosa (AN) is currently unknown.

Methods

We measured fasting serum concentrations of MIC-1 in patients with AN before and after 2-month nutritional treatment and explored its relationship with nutritional status, metabolic and biochemical parameters. Sixteen previously untreated women with AN and twenty-five normal-weight age-matched control women participated in the study. We measured serum concentrations of MIC-1 and leptin by ELISA, free fatty acids by enzymatic colorimetric assay, and biochemical parameters by standard laboratory methods; determined resting energy expenditure by indirect calorimetry; and assessed bone mineral density and body fat content by dual-energy X-ray absorptiometry. ANOVA, unpaired t-test or Mann-Whitney test were used for groups comparison as appropriate. The comparisons of serum MIC-1 levels and other studied parameters in patients with AN before and after partial realimentation were assessed by paired t-test or Wilcoxon Signed Rank Test as appropriate.

Results

At baseline, fasting serum MIC-1 concentrations were significantly higher in patients with AN relative to controls. Partial realimentation significantly reduced serum MIC-1 concentrations in patients with AN but it still remained significantly higher compared to control group. In AN group, serum MIC-1 was inversely related to Buzby nutritional risk index, serum insulin-like growth factor-1, serum glucose, serum total protein, serum albumin, and lumbar bone mineral density and it significantly positively correlated with the duration of AN and age.

Conclusions

MIC-1 concentrations in AN patients are significantly higher relative to healthy women. Partial realimentation significantly decreased MIC-1 concentration in AN group. Clinical significance of these findings needs to be further clarified.

Binge-like eating in mice

OBJECTIVE

Given the lack of reliable murine model of binge-like eating, we tried to induce this pathological behavior in mice.

METHOD

We used an experimental protocol mimicking the etiological factors involved in the development of binge eating in humans, that is, food restriction, refeeding (R-R) in presence of high palatable food, and stress (S).

RESULTS

Mice subjected to at least three cycles of R-R plus S (forced swimming stress), showed a binge-like behavior evident as early as 4 h, persisting 24 h after stress application and not associated to depressive-like behavior. However, after the third R-R/S cycle, food intakes of mice returned to normal levels.

DISCUSSION

(i) at least three cycles of R-R plus S are required to promote abnormal eating in mice, (ii) this is not associated to depressive-like behaviors, and (iii) the enhanced pathological behavior showed a transient nature not persisting after the third R-R/S cycle.

Relevance of animal models to human eating disorders and obesity

BACKGROUND AND RATIONALE

This review addresses the role animal models play in contributing to our knowledge about the eating disorders anorexia nervosa (AN) and bulimia nervosa (BN) and obesity.

OBJECTIVES

Explore the usefulness of animal models in complex biobehavioral familial conditions, such as AN, BN, and obesity, that involve interactions among genetic, physiologic, psychological, and cultural factors.

RESULTS AND CONCLUSIONS

The most promising animal model to mimic AN is the activity-based anorexia rodent model leading to pathological weight loss. The paradigm incorporates reward elements of the drive for activity in the presence of an appetite and allows the use of genetically modified animals. For BN, the sham-feeding preparation in rodents equipped with a gastric fistula appears to be best suited to reproduce the postprandial emesis and the defects in satiety. Animal models that incorporate genes linked to behavior and mood may clarify biobehavioral processes underlying AN and BN. By contrast, a relative abundance of animal models has contributed to our understanding of human obesity. Both environmental and genetic determinants of obesity have been modeled in rodents. Here, we consider single gene mutant obesity models, along with models of obesigenic environmental conditions. The contributions of animal models to obesity research are illustrated by their utility for identifying genes linked to human obesity, for elucidating the pathways that regulate body weight and for the identification of potential therapeutic targets. The utility of these models may be further improved by exploring the impact of experimental manipulations on the behavioral determinants of energy balance.

Appetite-Related Gut Peptides in Obesity and Binge Eating Disorder

The worldwide increase in obesity prevalence is a result of positive energy balance, with energy intake exceeding expenditure. The eating behavior in obesity ranges from mild passive overconsumption to excessive overeating with loss of control observed in binge eating disorder (BED). The signaling systems that underlie appetite control in BED are complex and, at this point, not well understood. The present review highlights the current knowledge of key components of the gut peptide system and examines evidence of defects in signaling that differentiate obese binge eaters from obese non-binge eaters. The signaling network underlying hunger, satiety, and metabolic status includes leptin and insulin from energy stores and cholecystokinin, glucagon-like peptide-1, peptide YY(3-36), and ghrelin from the gastrointestinal tract. Of the many gastrointestinal peptides, ghrelin is the only established appetite-stimulating one, whereas cholecystokinin, glucagon-like peptide-1, and peptide YY(3-36) promote satiety. Adipose tissue provides hormonal signals via leptin and insulin to the brain about energy stores and likely from adiponectin and resistin. Binge eating has been related to a dysfunction in the ghrelin signaling system. Moreover, the larger gastric capacity observed in BED may further reduce satiety signals and contribute to overeating.

Preventing excessive weight gain in adolescents: interpersonal psychotherapy for binge eating

The most prevalent disordered eating pattern described in overweight youth is loss of control (LOC) eating, during which individuals experience an inability to control the type or amount of food they consume. LOC eating is associated cross-sectionally with greater adiposity in children and adolescents and seems to predispose youth to gain weight or body fat above that expected during normal growth, thus likely contributing to obesity in susceptible individuals. No prior studies have examined whether LOC eating can be decreased by interventions in children or adolescents without full-syndrome eating disorders or whether programs reducing LOC eating prevent inappropriate weight gain attributable to LOC eating. Interpersonal psychotherapy, a form of therapy that was designed to treat depression and has been adapted for the treatment of eating disorders, has shown efficacy in reducing binge eating episodes and inducing weight stabilization among adults diagnosed with binge eating disorder. In this paper, we propose a theoretical model of excessive weight gain in adolescents at high risk for adult obesity who engage in LOC eating and associated overeating patterns. A rationale is provided for interpersonal psychotherapy as an intervention to slow the trajectory of weight gain in at-risk youth, with the aim of preventing or ameliorating obesity in adulthood.

Peripheral and central signals in the control of eating in normal, obese and binge-eating human subjects

The worldwide increase in the incidence of obesity is a consequence of a positive energy balance, with energy intake exceeding expenditure. The signalling systems that underlie appetite control are complex, and the present review highlights our current understanding of key components of these systems. The pattern of eating in obesity ranges from over-eating associated with binge-eating disorder to the absence of binge-eating. The present review also examines evidence of defects in signalling that differentiate these sub-types. The signalling network underlying hunger, satiety and metabolic status includes the hormonal signals leptin and insulin from energy stores, and cholecystokinin, glucagon-like peptide-1, ghrelin and peptide YY3-36 from the gastrointestinal tract, as well as neuronal influences via the vagus nerve from the digestive tract. This information is routed to specific nuclei of the hypothalamus and brain stem, such as the arcuate nucleus and the solitary tract nucleus respectively, which in turn activate distinct neuronal networks. Of the numerous neuropeptides in the brain, neuropeptide Y, agouti gene-related peptide and orexin stimulate appetite, while melanocortins and alpha-melanocortin-stimulating hormone are involved in satiety. Of the many gastrointestinal peptides, ghrelin is the only appetite-stimulating hormone, whereas cholecystokinin, glucagon-like peptide-1 and peptide YY3-36 promote satiety. Adipose tissue provides signals about energy storage levels to the brain through leptin, adiponectin and resistin. Binge-eating has been related to a dysfunction in the ghrelin signalling system. Moreover, changes in gastric capacity are observed, and as gastric capacity is increased, so satiety signals arising from gastric and post-gastric cues are reduced. Understanding the host of neuropeptides and peptide hormones through which hunger and satiety operate should lead to novel therapeutic approaches for obesity; potential therapeutic strategies are highlighted.

Behavioral models of binge-type eating

PURPOSE

To describe and evaluate behavioral models of binge-type eating.

DATA IDENTIFICATION

Studies were identified using Medline and hand searches of bibliographies of identified articles.

STUDY SELECTION

Isomorphic studies were selected that were judged to have some measure of construct validity.

DATA EXTRACTION

Face and construct validity were assessed, as well as simplicity and cost of use.

RESULTS OF DATA SYNTHESIS

Several different models of binge-type eating exist, each with different strengths of validity and use. These include models using sham feeding, restriction/refeeding cycles and/or stress, limited access (LA) to optional foods, and eating induced by operant schedules of behavior.

CONCLUSIONS

We concur with Harry Harlow, who was quoted by Gerry Smith as saying: "You'd be crazy to use animal models, but you'd also be crazy not to use them."

What is this thing called BED? Current status of binge eating disorder nosology

OBJECTIVE

Although binge eating has been recognized as a clinically relevant behavior among the obese for more than four decades, the concept of binge eating disorder (BED) as a distinct psychiatric diagnosis is of much more recent origin. This article presents four ways of conceptualizing BED: a distinct disorder in its own right, as a variant of bulimia nervosa, as a useful behavioral subtype of obesity, and as a behavior that reflects psychopathology among the obese. It also summarizes the evidence supporting and disconfirming each model.

METHOD

The literature subsequent to the development of DSM-IV regarding the reliability and validity of BED and related conditions was reviewed selectively.

RESULTS

The preponderance of the evidence suggests that BED differs importantly from purging bulimia nervosa and that BED is not a strikingly useful behavioral subtype of obesity.

DISCUSSION

Further study is needed to definitively determine the validity of BED as a distinct eating disorder.

Cognitive-behavioral therapy and nutritional counseling in the treatment of bulimia nervosa and binge eating

The goals of manual-based cognitive-behavioral therapy (CBT) and nutritional counseling for eating disorders are similar, namely, eliminating dysfunctional patterns of eating. Modifying these behaviors requires specific therapeutic expertise in the principles and procedures of behavior change that is not typically part of the training of nutritionists and dieticians or mental health professionals without specific expertise. We discuss ways in which principles of behavior change can be applied to eating disorders by non-CBT experts. Specific nutritional rehabilitation programs have the potential to augment CBT in addressing the array of appetitive abnormalities present in eating disorder patients. The dysfunctional appetitive, hedonic, and metabolic characteristics of patients with bulimia nervosa (BN) and binge eating disorder are reviewed. These abnormalities constitute potential target areas that might be more fully addressed by nutritional interventions designed to restore normal appetitive function.

Binge eating disorder: a review of the literature after publication of DSM-IV

Binge eating disorder (BED) is a syndrome marked by recurrent episodes of binge eating, in the absence of the regular use of inappropriate compensatory behaviors. Since the inclusion of BED in DSM-IV as a Diagnostic Category in Need of Further Research, a great deal of research has been conducted. This paper reviews research on BED since publication of DSM-IV in 1994. We conclude that questions about the definition of BED persist. Furthermore, recent studies which have strictly used the DSM-IV definition of BED have found that the full syndrome is found in less than 3% of obese adults seeking weight loss treatment and occurs in less than 1% of the general adult population. Binge eating is a common symptom associated with obesity, however. BED may be conceptualized as a psychiatric syndrome or it may be viewed as a behavioral symptom associated with obesity. We conclude that clarification of this conceptual issue is needed if research on BED is to progress.