Table of Contents
What is an eating disorder?
Eating disorders include anorexia nervosa, a form of self-starvation; bulimia nervosa, in which individuals engage in repetitive cycles of binge-eating alternating with self-induced vomiting or starvation; binge-eating disorder (BED), which resembles bulimia but without compensatory behaviors to avoid weight gain (e.g. vomiting, excessive exercise, laxative abuse); avoidant restrictive food intake disorder (ARFID) in which people may have lack of interest in food, avoid certain textures or types of foods, or have fears and anxieties about consequences of eating unrelated to shape or weight concerns (e.g. fear of choking, vomiting or abdominal discomfort) and other specified feeding and eating disorders (OSFED). Eating disorders can occur in any age group, gender, ethnic or racial group.
Anorexia nervosa and bulimia are psychiatric illnesses that center on food and its consumption and are usually characterized by:
- Excessive preoccupation with food and dissatisfaction with one’s body shape or weight
- A compulsion to engage in extreme eating habits and unhealthy methods of weight control such as:
o Fasting or binge-eating
o Excessive exercise
o Self-induced vomiting
o Chewing and spitting or regurgitating food
o Excessive laxative, diuretic, or diet pill abuse.
These unhealthy behaviors and preoccupations can develop into a consuming passion and come to interfere with physical, psychological and social well-being.
Eating disorders have many causes. They may be triggered by stressful life events, including a loss or trauma; relationship difficulties; physical illness; or a life change such as entering one’s teens, starting college, marriage or pregnancy. An eating disorder may develop in association with another psychiatric illness such as a depressive disorder, obsessive-compulsive disorder, or substance abuse. Current research indicates some people are more genetically predisposed to developing an eating disorder than others.
How common are eating disorders?
The eating disorders anorexia nervosa and bulimia nervosa, respectively, affect 0.5 percent and 2-3 percent of women over their lifetime. The most common age of onset is between 12-25. Although much more common in females, 10 percent of cases detected are in males. Binge eating disorder and OSFED are more common and rates of ARFID are not yet known as this diagnosis was defined relatively recently.
What is the difference between anorexia nervosa and bulimia?
Both anorexia nervosa and bulimia are characterized by an overvalued drive for thinness and a disturbance in eating behavior. The main difference between diagnoses is that anorexia nervosa is a syndrome of self-starvation involving significant weight loss of 15 percent or more of ideal body weight, whereas patients with bulimia nervosa are, by definition, at normal weight or above.
Bulimia is characterized by a cycle of dieting, binge-eating and compensatory purging behavior to prevent weight gain. Purging behavior includes vomiting, diuretic or laxative abuse. When underweight individuals with anorexia nervosa also engage in bingeing and purging behavior the diagnosis of anorexia nervosa supercedes that of binge/purging type.
Excessive exercise aimed at weight loss or at preventing weight gain is common in both anorexia nervosa and in bulimia.
What causes an eating disorder?
Eating disorders are believed to result from a combination of biological vulnerability, environmental, and social factors. A useful way of thinking about what causes an eating disorder is to distinguish predisposing, precipitating and perpetuating factors that contribute to its onset and maintenance.
- Predisposing factors include genetic vulnerability. Family and twin studies suggest that eating disorders run in families. Genetic studies are currently underway to isolate genes contributing to risk for an eating disorder.
- Precipitating factors including behaviors such as dieting or exercise, or stressors including illness, trauma or loss, which can trigger the onset of the disorder.
- Once the eating disorder takes hold however it is sustained largely by perpetuating factors that contribute to its maintenance. These maintaining factors can include physiological consequences of starvation or of binge purge behaviors, or anxiety and avoidance behaviors associated with the consumption of various foods. Starvation slows gastrointestinal transit resulting in early satiety (fullness) and constipation and it also increases preoccupation with food and the risk of eventual progression to binge-eating. Frequent self-induced vomiting can also lead to gastrointestinal dysmotility and to the development of additional symptoms and behaviors including spontaneous regurgitation, reflux and vomiting. For underweight patients, achievement of a low normal weight is essential for recovery, whilst for all patients normalizing eating and weight control behaviors and establishing healthier eating habits and coping strategies, is a priority.
Are certain personality traits more common in individuals with eating disorders?
Individuals who develop eating disorders, especially those with the restricting subtype of anorexia nervosa are often perfectionistic, eager to please others, sensitive to criticism, and self-doubting. They may have difficulty adapting to change and be routine bound. A smaller group of patients with eating disorders have a more extroverted temperament and are novelty-seeking and impulsive with difficulty maintaining stable relationships. There is no one personality associated with eating disorders, however.
What forms of treatment are effective for anorexia nervosa?
Treatment of anorexia nervosa involves nutritional rehabilitation to normalize weight and eating behavior. Psychotherapy is aimed at correcting irrational preoccupations with weight and shape, managing challenging emotions and anxieties and preventing relapse. Interventions include monitoring weight gain, prescribing an adequate diet, and admitting patients who fail to gain weight to a specialty inpatient or partial hospitalization program. Specialty programs combining close behavioral monitoring and meal support with psychological therapies are generally very effective in achieving weight gain in patients unable to gain weight in outpatient settings. The fear of fatness and body dissatisfaction characteristic of the disorder tend to extinguish gradually over several months once target weight and normal eating patterns are maintained, and 50-75% of patients eventually recover. No medications have been shown to significantly facilitate weight gain in patients with this disorder. In the case of patients under 18 years of age, family therapy aimed at helping parents support normal eating in their child has been found to be more effective than individual therapy alone.
What forms of treatment are effective for bulimia nervosa?
Most uncomplicated cases of bulimia nervosa can be treated on an outpatient basis although inpatient treatment is occasionally indicated. The best psychological treatment is cognitive-behavioral therapy, which involves self-monitoring of thoughts, feelings, and behaviors related to the eating disorder. Therapy is focused on normalizing eating behavior and identifying environmental triggers and irrational thoughts or feeling states that precipitate bingeing or purging. Patients are taught to challenge irrational beliefs about weight and self-esteem. Several medications have also been shown to be effective in decreasing bingeing and purging behaviors in bulimia.
What about the treatment of other eating disorders including BED, ARFID and OSFED?
Eating disorders are behavioral problems and the most successful modalities of treatment all focus on normalizing eating and weight control behaviors whilst managing uncomfortable thoughts and feelings. Increasingly, we understand eating disorders as not just psychological problems but as disorders of learning and habit. Changing established habits can feel challenging, however practice of healthy eating behavior under expert therapeutic guidance helps develop skills needed to manage anxieties regarding food, weight and shape — all of which fade over time with the gradual achievement of mastery over recovery.