Eating and Weight Disorders

Carlos M. Grilo

• Publisher: Psychology Press
• Year: 2014
• eBook ISBN: 9781317821861
• Topic: Medicine
• Subtopic: Psychiatry & Mental Health

Eating disorders refer to a range of problems characterized by abnormal eating behaviours and beliefs about eating, weight, and shape. Eating disorders, which are classified as psychiatric problems, and obesity, which is classified as a general medical condition, reflect a diverse and perplexing array of biological, social, and psychological phenomena. Beginning with a comprehensive overview of eating and weight disorders, this volume also covers:

• anorexia nervosa
• bulimia nervosa
• atypical eating disorders and binge eating disorders
• obesity.

Including the most up-to-date research, Carlos Grilo provides a balanced and authoritative overview of current thinking in the fields of eating disorders and obesity with broad yet in-depth coverage of the areas. This highly readable book is an indispensable resource to students and professionals in clinical psychology, health psychology, and psychiatry.

1 Overview of eating and weight disorders

Bodies to die for

This book provides an overview of eating and weight disorders. Eating disorders refer to a range of problems characterized by abnormal eating behaviors and beliefs about eating, weight, and shape. Obesity refers to excess body fat. Most persons with eating disorders are not obese. Most obese persons do not have eating disorders although many may suffer from disordered eating. Eating and weight concerns appear to have become ubiquitous in westernized societies. A careful analysis by Colditz (1992) revealed that Americans spent roughly $33 billion annually in the early 1990s on a plethora of weight loss products and services. This spending on weight loss products grew to roughly $50 billion annually by the turn of the century. Eating and weight disorders are much more than just concerns with aesthetics. Eating disorders, which are classified as psychiatric problems, and obesity, which is classified as a general medical condition, reflect a diverse and perplexing array of biological, social, psychological phenomena.

As this book will summarize, eating and weight disorders reflect “bodies to die for” in many ways. At one end of the weight continuum is anorexia nervosa, a relatively rare problem affecting primarily young women. Individuals suffering from anorexia nervosa go to truly remarkable lengths to lose weight despite their emaciated states. Anorexia nervosa has one of the highest mortality rates of any psychiatric disorder (Sullivan, 1995) which translates to more than a twelve-fold increase in death rate relative to their age peers. At the other end of the weight continuum is obesity, a common problem that is continuing to increase in prevalence despite pervasive societal pressures and individual desires to achieve thinness. Obesity has one of the highest associated mortality rates of any medical condition. In the United States alone, over 300,000 premature deaths are attributable to obesity annually (Allison, Fontaine, Manson, Stevens, & VanItallie, 1999). Obesity substantially decreases life expectancy and increases early mortality (Peeters, Bonneux, Barendregt, & Nusselder, 2003). The steady increase in life expectancy observed since the nineteenth century has slowed during the past three decades (Oeppen & Vaugel, 2002) and a recent sophisticated analysis suggests that the United States may face a decline in average life expectancy due to the effects of obesity on longevity (Olshansky et al., 2005).

In this introductory chapter, an overview of eating disorders and obesity is provided. Eating is an everyday behavior that addresses a very basic biological need for energy. Problems with eating and weight have undoubtedly always existed. There exist rich accounts of behaviors ranging from self-starvation (Vandereycken & Van Deth, 1994) to voracity and gorging (Parry-Jones & Parry-Jones, 1991; Stein & Laasko, 1988) dating back several centuries. Inspection of historical and medical sources, however, suggests that what we currently conceptualize as eating disorders may best be thought of as “new” or “modern” problems characteristic of the twentieth century (Vandereycken, 2002; Vandereycken & Van Deth, 1994). Similarly, obesity has likely always existed in civilized societies. Visitors to the western world's art museums readily recall the pervasive “plumpness” emphasized as the preferred or idealized body images throughout the fifteenth through eighteenth centuries. Bray (1993, 2002b), in his commentaries about early scientific contributions to energy balance and obesity, noted that a series of monographs appeared in the mid-nineteenth century including Banting's (1863) “A Letter on Corpulence Addressed to the Public” (reprinted as Banting (1993) Letter on corpulence addressed to the public, 3rd edition, in Obesity Research), which perhaps represents the first diet book.

Defining eating and weight disorders

Current classification or diagnostic schemes include eating disorders (abnormal eating behaviors and beliefs about eating and body shape) as psychiatric or mental disorders and obesity (excess body fat) as a general physical or medical condition. It can, at times, be difficult to determine what is aberrant or “non-normative” and how, or where, to draw a line. The major classification systems currently use categorical rather than dimensional methods to describe or label problems. Emerging research suggests that our conceptual models of eating-related problems are probably too simplistic and that neither categorical nor dimensional approaches adequately capture the full range of aberrant eating (Bulik, Sullivan, & Kendler, 2000a; Keel et al., 2004 Williamson, Gleaves, & Stewart, 2005; Williamson et al., 2002). Categorical approaches, which reflect our evolving attempts to “carve nature at its joints,” have both advantages and disadvantages, but nonetheless provide us with a common language or starting point.

Classification of eating disorders and obesity

Both of the major classification systems for psychiatric disorders, the International Classification of Diseases, 10th revision (ICD-10; World Health Organization [WHO], 1992) and the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV; American Psychiatric Association [APA], 1994), include eating disorder diagnoses. At a general level, an eating disorder diagnosis — like any mental disorder category in the DSM-IV (APA, 1994) — refers to a clinically-meaningful behavioral or psychological pattern that is associated with distress (e.g., upsetting or painful symptoms) or disability (e.g., impairment in functioning) or with substantially increased risk of morbidity, disability, or mortality. Both DSM-IV and ICD-10 include two specific eating disorder diagnoses (Anorexia Nervosa and Bulimia Nervosa) and a general less-specified category (Eating Disorder Not Otherwise Specified in the DSM-IV or Atypical Eating Disorders in the ICD-10). Obesity is classified in the ICD-10 as a general medical condition but is not included in the DSM-IV because it has not been consistently associated with either a behavioral or a psychological pattern or syndrome. Note that if there is evidence that psychological features are salient and of importance in the cause or maintenance of an individual's obesity, this can be assigned a diagnosis of Psychological Factors Affecting Medical Condition.

There are also three disorders of feeding or eating (Pica, Rumination Disorder, and Feeding Disorder of Infancy or Early Childhood) included in a section labeled “Feeding and Eating Disorders of Infancy or Early Childhood” in the DSM-IV. These three childhood problems will not be considered in this book but are defined here for the reader. Pica refers to a persistent pattern of eating nonnutritive substances by young children. Rumination disorder refers to repeated regurgitation (without any observable nausea, disgust, or attempt to vomit) and rechewing of food without any gastrointestinal or medical reason. Feeding disorder of infancy or early childhood refers to the persistent failure to eat adequately and thus to gain sufficient weight for age.

TABLE 1.1
Anorexia nervosa: Definition and diagnostic criteria

A.	Low weight (i.e., less than 85% of expected).
B.	Intense fear of gaining weight or becoming fat.
C.	Disturbance in perception, experience, or evaluation of weight or shape.
D.	Amenorrhea in postmenarcheal females.
Specify subtype:
Restricting type: not regularly engaged in binge eating or purging behaviors (self-induced vomiting or the misuse of laxatives, diuretics, or enemas).
Binge eating/purging type: regularly engaged in binge eating or purging behaviors.

Based on the four criteria and subtyping in the Diagnostic and statistical manual of mental disorders (4th ed.; DSM-IV) published by the American Psychiatric Association (1994).

Anorexia nervosa (AN)

Table 1.1 lists the DSM-IV (APA, 1994) diagnostic criteria for anorexia nervosa. There are four criteria reflecting behavioral, psychological, and biological domains and there are two specified subtypes.

Refusal to maintain minimally normal weight

The first criterion, a behavioral criterion, is the refusal to maintain a minimally normal weight for age and height. This is defined as less than 85% of what is expected weight. This criterion can be met by a person losing weight to fall below 85% of what is normal or failing to gain weight during a period of growth or development and thus failing to achieve at least 85% of what is considered normal. There is general agreement about the need for this criterion although the exact weight threshold or optimal level is less clear. In principle it should clinically reflect when starvation symptoms take over or when physical problems or consequences begin. The ICD-10 includes a guideline of requiring a body mass index (kg/m²) of less than 17.5.

In most cases, the low weight is achieved primarily by very severe or restrictive eating. Individuals typically begin by excluding or eliminating foods that are thought to be fattening resulting in reduced total food intake and weight loss. With increasing weight loss, the eating becomes increasingly restrictive in both quantity and type resulting in both greater weight loss and perceived control over food. Most individuals end up eating remarkably small and carefully selected amounts and types of (low fat) food. In addition to the very severe food restriction and periods of fasting, some individuals employ additional methods of weight loss including different purging methods (i.e., self-induced vomiting, misuse of laxatives or diuretics) and excessive exercise.

Intense fear of fat

The second criterion involves an intense fear of gaining weight or becoming fat. This fear can be rather intense and it is remarkable since the individual is, by any objective standard, considerably underweight. A common clinical observation is that this fear does not lessen with continued weight loss, but instead can actually intensify in many cases as the individual becomes even more emaciated. It is worth noting here that this criterion has evolved somewhat from earlier views that focused exclusively on the presumed body image disturbance driven primarily by overestimation of size. While many individuals with anorexia nervosa do substantially overestimate their size, this is not universal nor is it specific to anorexia nervosa. Current views highlight the attitudinal or psychological dimensions of these body concerns and intense fear of fatness.

Disturbance in perception, experience, or overevaluation of weight or shape

The third criterion, thought by many to represent the specific psychopathology of eating disorders, involves attitudinal and psychological disturbances in which weight and shape are experienced, weight and shape concerns unduly influence self-evaluation and self-worth, or a denial of the seriousness or danger of the low weight and extreme dieting. These specific disturbances distinguish eating disorders from other psychiatric problems.

Overall, this criterion can reflect a range in disturbance or distortion in how body weight and shape are experienced. Many individuals feel or experience their bodies globally as overweight while some have heightened and distressing concerns about specific body parts or regions. The ICD-10 focuses almost exclusively, and more narrowly than the DSM-IV, on this specific attitudinal disturbance (self-perception of being too fat and the fear or dread of fatness) as fueling the self-imposed low weight. Many individuals deny the seriousness of the low weight and its serious medical complications. Indeed, it is extraordinarily rare for an individual to voice concern about their weight loss even when it approaches truly dangerous levels.

The final example of this attitudinal disturbance involves the overevaluation of weight or shape. It is precisely this specific feature that is thought to represent the core psychopathology of eating disorders (Fairburn & Harrison, 2003). Individuals with eating disorders overevaluate their weight and shape and judge their self-esteem and self-worth primarily in terms of weight/shape and their ability to control them. Self-evaluation unduly influenced by weight/shape is a related but distinct feature from body dissatisfaction (Cooper & Fairburn, 1993; Masheb & Grilo, 2003). Body dissatisfaction is experienced by many individuals in our society regardless of whether or not they have an eating disorder. The ubiquitous nature of body shape concerns, particularly among women in westernized societies, has even been referred to as “normative discontent” (Rodin, Silberstein, & Striegel-Moore, 1985). The overevaluation criterion reflects a different concept. In contrast to most individuals who judge self-worth on the basis of several important aspects of their lives (e.g., relationships, roles as parents or partners, work or academic success, hobbies or activities, etc.), individuals with eating disorders tend to judge their self-worth based on their perception of their weight/ eating and their perceived ability to control them.

Thus, in the case of an individual with anorexia nervosa, the weight loss and control over eating are viewed as important achievements. Not only is the weight loss not viewed as a problem, it is instead viewed as an important achievement or accomplishment. Similarly, the ability to severely restrict food intake is viewed as a sign of self-discipline and positive control. While this control continues it offers a slight boost to self-worth, but when perceived lapses in control occur significant emotional upset and distress follow. This core psychopathology explains the remarkable drive to control eating and weight and why these individuals have such limited motivation to follow suggestions to eat more.

Amenorrhea

The fourth criterion is, in postmenarcheal females, amenorrhea which is defined as the absence of at least three consecutive menstrual cycles. The amenorrhea is due to abnormally low levels of estrogen secretion and diminished secretion of follicle-stimulating hormone and luteinizing hormone by the pituitary. In prepubertal females, anorexia nervosa may delay menarche. Of note is that in the ICD-10 this criterion is referred to more broadly as a widespread endocrine disorder involving the hypothalamic-pituitary-gonadel axis, and lists loss of sexual interest and potency in men as an example in addition to the amenorrhea in women.

Amenorrhea in anorexia nervosa is poorly understood and is the target of considerable debate regarding its usefulness as a criterion (Cachelin & Maher, 1998). Amenorrhea is a common feature that seems to result, in part, from weight and body fat lost. Amenorrhea, however, is sometimes seen in individuals before large weight losses and sometimes persists after weight gain. Several studies have found that wo...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Series preface
• 1 Overview of eating and weight disorders: Bodies to die for
• 2 The epidemiology and nature of eating and weight disorders
• 3 Understanding, assessing, and treating anorexia nervosa
• 4 Understanding, assessing, and treating bulimia nervosa
• 5 Atypical eating disorders and binge eating disorder: Assessment and treatment
• 6 Obesity: Assessment and treatment
• Further reading and resources
• References
• Author index
• Subject index