40 Feeding and Eating Disorders

3rd edition as of July 2023

Module Overview

In this module, we will discuss matters related to feeding and eating disorders to include their clinical presentation, epidemiology, comorbidity, etiology, and treatment options. Our discussion will cover anorexia nervosa, bulimia nervosa, and binge eating disorder. Be sure you refer Modules 1-3 for explanations of key terms (Module 1), an overview of the various models to explain psychopathology (Module 2), and descriptions of the therapies (Module 3).

Module Outline

• Clinical Presentation
• Epidemiology
• Comorbidity

Module Learning Outcomes

• Describe how feeding and eating disorders present.
• Describe the epidemiology of feeding and eating disorders.
• Describe comorbidity in relation to feeding and eating disorders.

Clinical Presentation

Section Learning Objectives

• Describe how anorexia nervosa presents.
• Describe how bulimia nervosa presents.
• Describe how binge-eating disorder (BED) presents.

Feeding and eating disorders are “…characterized by a persistent disturbance of eating or eating-related behavior that results in the altered consumption or absorption of food and that significantly impairs physical health or psychosocial functioning” (APA, 2022, pg. 371). They are very serious, yet relatively common mental health disorders, particularly in Western society, where there is a heavy emphasis on thinness and physical appearance. In fact, 13% of adolescents will be diagnosed with at least one eating disorder by their 20th birthday (Stice, Marti, & Rohde, 2013). Furthermore, a large number of adolescents will engage in significant disordered eating behaviors just below the clinical threshold (Culbert, Burt, McGue, Iacono & Klump, 2009). While there is no exact cause for eating disorders, the combination of biological, psychological, and sociocultural factors has been identified as major contributors in both the development and maintenance of eating disorders.

Within the DSM 5-TR (APA, 2022), six disorders are classified under the Feeding and Eating Disorders chapter: pica, rumination disorder, avoidant/restrictive food intake disorder, anorexia nervosa, bulimia nervosa, and binge-eating disorder. In this module, we will cover the latter three whose diagnostic criteria are mutually exclusive, meaning that only one of these diagnoses can be assigned at any given time due to substantial differences in their clinical course, outcome, and treatment needs, despite a number of common psychological and behavioral features.

Anorexia Nervosa

Anorexia nervosa involves the restriction of energy intake, which leads to significantly low body weight relative to the individual’s age, sex, and development. This restriction is often secondary to an intense fear of gaining weight or becoming fat, despite the individual’s low body weight. Altered perception of self and an over-evaluation of one’s body weight and shape contribute to this disturbance of body size.

Typical warning signs and symptoms are divided into two different categories: emotional/behavioral and physical. Some emotional and behavioral symptoms include dramatic weight loss; preoccupation with food, weight, calories, etc.; frequent comments about feeling “fat;” eating a restricted range of foods; making excuses to avoid mealtimes; and not eating in public. Physical changes may include dizziness, difficulty concentrating, feeling cold, sleep problems, thinning hair/hair loss, and muscle weakness, to name a few. When the individual loses weight, they view this as an impressive achievement and a sign of extraordinary discipline, while weight gain is seen as an unacceptable failure of self-control (APA, 2022).

The onset of the disorder typically begins with mild dietary restrictions such as eliminating carbs or specific fatty foods. As weight loss is achieved, the dietary restrictions progress to more severe, e.g., under 500 calories/day.  Symptoms present in adolescence or young adulthood and rarely before puberty or after age 40. The onset of the disorder typically is preceded by a stressful life event such as leaving home for college.

Bulimia Nervosa

Unlike anorexia nervosa where there is solely restriction of food, bulimia nervosa involves a pattern of recurrent binge eating behaviors. Binge eating can be defined as a discrete period of time where the amount of food consumed is significantly more than most people would eat during a similar time period. Individuals with bulimia nervosa often report a sense of lack of control over-eating during these binge-eating episodes. While not always the case, these binge-eating episodes are followed by a feeling of disgust with oneself, which leads to a compensatory behavior to rid the body of the excessive calories. These compensatory behaviors include vomiting, use of laxatives, fasting (or severe restriction), diuretics or other medications, or excessive exercise. This cycle of binge eating and compensatory behaviors occurs on average, at least once a week for three months (National Eating Disorder Association website; APA, 2022).

It is important to note that while there are periods of severe calorie restriction like anorexia, the two disorders cannot be diagnosed simultaneously. Therefore, it is important to determine the individual’s weight when distinguishing between anorexia and bulimia. If an individual has a significantly low body weight and engages in binge/purging behaviors, the diagnosis is anorexia; if the individual does not have a significantly low body weight and engages in binge/purging behaviors, the diagnosis is bulimia.

Signs and symptoms of bulimia nervosa are similar to anorexia nervosa. These symptoms include but are not limited to hiding food wrappers or containers after a bingeing episode, feeling uncomfortable eating in public, developing food rituals, limited diet, disappearing to the bathroom after eating a meal, and drinking excessive amounts of water or non-caloric beverages. Additional physical changes include weight fluctuations both up and down, difficulty concentrating, dizziness, sleep disturbance, and possible dental problems due to purging post binge eating episode.

Symptoms of bulimia nervosa typically present later in development – adolescence or early adulthood. Like anorexia nervosa, bulimia nervosa initially presents with mild restrictive dietary behaviors; however, episodes of binge eating interrupt the dietary restriction, causing bodyweight to rise around normal levels. In response to weight gain, patients engage in compensatory behaviors or purging episodes to reduce body weight. This cycle of restriction, binge eating, and calorie reduction often occurs for years before seeking help.

Additionally, those with bulimia are often ashamed of their eating problems and attempt to hide the symptoms. The binge eating occurs in secrecy or as inconspicuously as possible. Common antecedents of binge eating include negative affect; interpersonal stressors; dietary restraint; boredom; and negative feelings linked to body weight, shape, and food.

Binge-Eating Disorder (BED)

Binge-eating disorder is similar to bulimia nervosa in that it involves recurrent binge eating episodes along with feelings of lack of control during the binge-eating episode. The binge-eating episodes are associated with at least three of the following: eating quicker than usual, eating until uncomfortably full, eating large amounts even if not hungry, eating alone, and feeling disgust with oneself or being depressed. Despite the feelings of shame and guilt post-binge, individuals with BED will not engage in vomiting, excessive exercise, or other compensatory behaviors. These binge eating episodes occur on average, at least once a week for 3 months.

Because these binge-eating episodes occur without compensatory behaviors, individuals with BED are at risk for obesity and related health disorders. Individuals with BED report feelings of embarrassment at the quantity of food consumed, and thus will often refuse to eat in public. Due to the restriction of eating around others, individuals with BED often engage in secret binge eating episodes in private, followed by discrete disposal of wrappers and containers.

While much is still being researched about binge-eating disorder, current research indicates that the onset of BED is adolescence to early adulthood but can begin later in life. Those who seek treatment tend to be older than those with either bulimia or anorexia. Binge eating has been found to be common in adolescent and college-age samples and for all, is associated with social role adjustment issues, impaired health-related quality of life and life satisfaction, and increased medical morbidity and mortality (APA, 2022).

Epidemiology

Section Learning Objectives

• Describe the epidemiology of anorexia nervosa.
• Describe the epidemiology of bulimia nervosa.
• Describe the epidemiology of binge eating disorder.

Anorexia Nervosa

According to the National Eating Disorder Alliance (NEDA) website, at any point in time more women (0.3-0.4%) than men (0.1%) will be diagnosed with anorexia. Anorexia nervosa is most prevalent in postindustrialized, high-income countries such as the United States, Australia, New Zealand, Japan, and many European countries. In the U.S., prevalence is lower among Latinx and non-Latinx Black Americans than non-Latinx Whites (APA, 2022).

Bulimia Nervosa

According to the NEDA website, at any point in time, 1.0% of women and 0.1% of men will meet the diagnostic criteria for bulimia nervosa. A study by Stice and Bohon (2012) found that between 1.1% and 4.6% of females and 0.1% to 0.5% of males will develop bulimia and that subthreshold bulimia occurs in 2.0% to 5.4% of adolescent females. The DSM reports that the 12-month prevalence ranges from 0.14% to 0.3% with higher rates in females and high-income countries. Rates are similar across ethnoracial groups across the U.S. (APA, 2022).

Binge Eating Disorder

Hudson et al. (2007) reports that BED is three times more common than anorexia and bulimia and is more common than breast cancer, HIV, and schizophrenia. It has also been found that between 0.2% and 3.5% of females and 0.9% and 2.0% of males will develop binge eating disorder with subthreshold binge eating disorder occurring in 1.6% of adolescent females (Stice & Bohon, 2012). The DSM reports a 12-month prevalence of 0.44% to 1.2% with rates 2-3 times higher in women, similar rates across ethnoracial groups in the United States and between most high-income industrialized countries (APA, 2022).

Comorbidity

Section Learning Objectives

• Describe the comorbidity of anorexia nervosa.
• Describe the comorbidity of bulimia nervosa.
• Describe the comorbidity of BED.

Anorexia Nervosa

Anorexia is rarely a single diagnosis. High rates of bipolar, depressive, and anxiety disorders are common among individuals with anorexia nervosa. Obsessive-compulsive disorder is more often seen in those with the restricting type of anorexia nervosa, whereas alcohol use disorder and other substance use disorders are more commonly seen in those with anorexia who engage in binge-eating/purging behaviors. Unfortunately, there is also a high rate of suicidality, with rates reported to be 18 times greater than in an age- and gender-matched comparison group. It is also estimated that between 9% and 25% of individuals with anorexia have attempted suicide (APA, 2022).

Bulimia Nervosa

The majority of individuals diagnosed with bulimia nervosa also present with at least one other mental disorder. Similar to anorexia nervosa, there is a high frequency of depressive symptoms (i.e., low self-esteem), as well as bipolar and depressive disorders. While some experience mood fluctuations because of their eating pattern (occurring at the same time or following the development of bulimia), some individuals will identify mood symptoms prior to the onset of bulimia nervosa (APA, 2022).

Anxiety, particularly social anxiety, is often present in those with bulimia nervosa. However, most mood and anxiety symptoms resolve once an effective treatment of bulimia is established. Substance use disorder, and in particular alcohol use disorder, is also prevalent in those with bulimia, with about a 30% prevalence among those with bulimia. The substance abuse begins as a compensatory behavior (e.g., stimulant use is used to control appetite and weight) and over time, as the eating disorder progresses, so does the substance abuse. There is also a percentage of individuals with bulimia nervosa who display personality features that meet the criteria for at least one personality disorder, most often borderline personality disorder. Finally, about one-quarter to one-third of individuals with bulimia have had suicidal ideation and a comparable amount have attempted suicide.

BED

Research shows that BED shares similar comorbidities with anorexia nervosa and bulimia nervosa. Common comorbidities include major depressive disorder and alcohol use disorder. About 25% of those with BED have shown suicidal ideation (APA, 2022).

“Feeding and Eating Disorders” is adapted from Fundamentals of Psychological Disorders by Alexis Bridley and Lee W. Daffin Jr., used under Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.