Eating disorders are relatively common occurrences in wealthy, industrialized countries, affecting up to 2 percent of women and approximately 0.8 percent of men. They are characterized by a persistent disturbance of eating patterns that leads to poor physical and/or psychological health. The major eating disorders are anorexia nervosa, bulimia nervosa, binge-eating disorder, avoidant/restrictive food intake disorder, pica, and rumination disorder.
Eating is an activity essential to survival, and the body has many built-in mechanisms that regulate appetite and eating. Eating patterns are normally influenced by many factors, environmental as well as biological, and cultural too. The causes of eating disorders are multiply influenced and complex.
Disordered eating patterns can be caused by feelings of distress or concern about body shape or weight, and they harm normal body composition and function. A person with an eating disorder may have started out just eating smaller or larger amounts of food than usual, but at some point, the urge to eat less or more can spiral out of control and the maladaptive patterns of eating take on a life of their own.
Given the complexity of eating disorders, considerable scientific research has been conducted in an effort to understand them, yet the biological, behavioral, and social underpinnings of the illnesses remain elusive. Eating disorders frequently develop during adolescence or early adulthood, but onset during childhood or later in adulthood is not unknown. Many adolescents are able to hide disordered eating behaviors from their family for months or years.
Nevertheless, eating disorders are treatable illnesses. Eating disorders frequently occur together with other psychiatric illnesses, such as depression, substance abuse, or anxiety disorders. In addition, people who suffer from eating disorders can experience a wide range of physical health complications, including serious heart conditions and kidney failure, which may lead to death. The recognition of eating disorders as real and treatable diseases is critically important.