Understanding Eating Disorders

It has been said that there is no category of illness more misunderstood than eating disorders. A simple search of the Internet clearly reveals that misconceptions about these conditions are commonplace. Confusion and false information abound: for example, are eating disorders a disease or a choice? Are people with eating disorders trying to get attention, or do they suffer from a serious condition? Are eating disorders “new” illnesses, or are they simply receiving more publicity of late?

According to National Statistics, as many as 10 million females and 1 million males are fighting a life and death battle with either anorexia nervosa or bulimia nervosa. Millions more reportedly struggle with Binge Eating Disorder. Yet because of the secretiveness and shame associated with these disorders, countless cases go unreported.

In addition, the rates are fast increasing – for example, we have seen increases in bulimia nervosa of nearly 35% during every five-year period since 1950. Statistics can seem so impractical, but the reality is that just one of the main categories of eating disorders, anorexia nervosa, ranks as the third most common chronic illness among adolescents, following obesity and asthma. Indeed, these illnesses are far more common then we may imagine: research shows that a full 35% of normal dieters progress to pathological dieting. Of those, 20-25% progress to partial or full-syndrome eating disorders. Nearly one-half of teenage girls and one-third of teenage boys use unhealthy weight control behaviors such as skipping meals, fasting, smoking cigarettes, vomiting, or taking laxatives.

What are eating disorders?

Eating disorders are serious and complex psychiatric disorders whose symptoms include a severe disturbance in eating behavior and often coincide with unhealthy weight loss and weight control methods (such as severe calorie restriction, food avoidance or self-starvation, excessive exercise, self-induced vomiting, and laxative abuse). The main types of eating disorders are as follows:

Types of eating disorders

Anorexia Nervosa is a potentially life-threatening illness characterized by the inability or refusal to maintain a healthy body weight, an intense fear of gaining weight, unhealthy weight loss and weight control methods (including inappropriate compensatory behaviors, and a distorted self-perception of body shape and size).

Bulimia Nervosa is a potentially life-threatening illness that also includes an intense fear of gaining weight, unhealthy weight loss and weight control methods (including inappropriate compensatory behaviors), and a distorted self-perception of body shape and size, along with the hallmark symptom of binge eating episodes that involve consuming large amounts of calories in a short period of time.

Binge Eating Disorder is an illness characterized by recurrent episodes of this kind of binge eating, along with the sense of loss of control over content and/or quantity of food consumed.

Note: binge eating is a potential symptom in all three types of disorders. In anorexia and bulimia, there is an attempt to compensate for calories consumed, either through self-induced vomiting, laxative abuse or excessive exercise, whereas in binge eating disorder, there is a lack of compensatory behaviors. There are also a plethora of similar warning signs including denial of hunger, being ritualistic about food (for example, chewing each bite a certain number of times, incessantly measuring food servings, counting the number of food items eaten), being vague or secretive about eating, frequently skipping meals, experiencing feelings of guilt after eating, exhibiting great concern about weight gain, abusing diet pills or prescription medications, and having a negative body image.

Additionally, it is important to note that research findings indicate that at least half of all people diagnosed with an eating disorder do not meet the full criteria for a primary eating disorder, either anorexia nervosa or bulimia nervosa. In such cases, an alternative diagnosis is given. According to current diagnostic standards (DSM-IV-TR) “eating disorder not otherwise specified” (or EDNOS) is the term used to describe clinically significant eating disturbances that meet some, but not all, of the diagnostic criteria of either anorexia nervosa or bulimia nervosa. Some of those diagnosed with EDNOS may have symptoms that closely align with diagnostic criteria of anorexia or bulimia but fall outside of this diagnosis based on just one criterion. It is important to note that a diagnosis of EDNOS is no less clinically significant than that of anorexia or bulimia, nor is it necessarily of less concern. EDNOS can indeed be quite serious and requires the same attention and level of treatment as another eating disorder diagnosis.

While EDNOS is actually the most common eating disorder (ED) diagnosis that we see in clinical practice, many people with EDNOS fall through the cracks because healthcare professionals are much less accustomed to looking for the “sub-clinical” signs of EDNOS. This is especially true when someone is of a normal weight. In addition, males are more likely to have EDNOS than anorexia and bulimia. As they are often overlooked as a population, this unfortunately prevents them from receiving adequate diagnosis and treatment.

In all cases, eating disorders produce significant stress and can result in debilitating, if not deadly, consequences. Complications resulting from eating disorders can affect all organ systems of the body and significantly impact patients’ cognitive, social, psychological and physical health. Indeed, eating disorders have the highest premature death rate among all mental illnesses with estimates of fatality occurring in as many as 5–20% of cases.

What causes an eating disorder?

Studies have determined that there is no single cause of these illnesses. Instead, we now know that a combination of factors can contribute to the development of an eating disorder. The presence of these risk factors can increase a person’s vulnerability to an eating disorder, and, when combined with triggering life events, they may increase the likelihood of developing an eating disorder. Each of the following factors has been shown to contribute to a person’s overall risk of developing an eating disorder: genetic and biological factors, developmental factors (including puberty and life transitions), social and cultural factors (including dieting, peer pressure, and cultural influences), and psychological factors (including temperament, anxiety, and severe stress).

Scientific studies have shown that some individuals may have a genetic predisposition toward developing an eating disorder, with some research indicating a hereditability factor greater than 50%. Multiple genetic influences (rather than a single, specific gene) appear to combine with environmental factors and lead to an increased risk for the illness.

Another area of biology that is important in understanding eating disorder risk is brain chemistry. Scientific investigations have shown that the regulation of certain brain chemicals called neurotransmitters, play an important role in certain psychiatric illnesses, such as depression and anxiety disorders. While we are just beginning the search into the role these chemicals may play in anorexia, there is increasing evidence that suggests neurotransmitters are a contributing factor in the course of an eating disorder.

Multiple areas of biological research have yielded additional advances in the understanding of anorexia. For example, certain digestive hormones (e.g., leptin and ghrelin) have been found at abnormal levels in some eating disorder patients. Also, it appears various hormones released in the body during times of stress may play a role. Thus, as you can well imagine, although the biological aspects of eating disorders are complex, and research in this area is still in its infancy, we are continually learning more about the interaction between biological and genetic components with other factors that may contribute to the development and course of these illnesses. Experts have been truly enlightened by recent research that has led to the definitive understanding that eating disorders are biological, as well as behavioral, illnesses.

The good news:

For the majority of people with eating disorders, recovery is possible and good health and well-being is attainable! Anyone in the eating disorder field — patients, families, and health care providers alike, can tell you that it takes time, support, and often a great deal of effort to recover from these illnesses, but hard work can and does lead to a true possibility of recovery. Most studies suggest that the majority of people with eating disorders achieve some degree of recovery (75–80%). Studies also indicate that even individuals with long-standing eating disorders can show improvement. However, outcomes are significantly better with early and intensive treatment, including adequate length of stay in an eating disorder facility, and appropriate follow up treatment. Early intervention can start someone with an eating disorder on the road to a healthier, happier, and balanced life.


Portions of the above information have been excerpted and/or revised from the book “100 Questions and Answers about Anorexia Nervosa” by Sari Fine Shepphird, Ph.D. (Jones & Bartlett Learning Publishers, 2010).