The Epidemiology of Eating Disorders in Children
Editor's Note: The American Academy of Pediatrics released a new Clinical Report - Identification and Management of Eating Disorders in Children and Adolescents in December 2010. The report documents an increasing incidence of eating disorders in boys, who now represent up to 10% of all cases, and younger children. The document emphasizes the importance of early detection and proper evaluation of children suspected of a disorder. Medical complications of eating disorders can affect any organ system and necessitate a range of management strategies including medical care, mental health treatment, and nutritional intervention. Medscape talked with the report's lead author, David S. Rosen, MD, MPH, Clinical Professor of Pediatrics, Internal Medicine, and Psychiatry at the University of Michigan Medical School, Ann Arbor, about the implications of this information for primary care.
Medscape: Dr. Rosen, the report clearly notes the changing epidemiology of eating disorders, including an increased incidence in boys, younger children, and minority children. Are you able to speculate on some of the reasons for these changes?
Dr. Rosen: Some of it is better case finding. In the past we weren't looking for or recognizing eating disorders in populations where we weren't expecting to see them. Some of it is simply recognizing eating disorders that have probably always been there, but there are probably also changes going on in who develops eating disorders in the first place. As the media change, as our eating habits change, as our nutrition practices change, as our concerns about obesity have become very acute, a lot of kids are thinking about nutrition in ways that they haven't been asked to before. In a certain vulnerable population, that message sometimes gets misdirected. There are unintended consequences, which can result in eating disorders.
Medscape: The report describes the increasing incidence in younger children. The committee looked at genetic and environmental variables as they affect this disorder and examined the role of puberty in activating a potential genetic predisposition to the traits that often accompany eating disorders such as perfectionism and behavior rigidity. Yet, there is a rising incidence in prepubertal children. Can you discuss some of the reasons for this rising incidence?
Dr. Rosen: Again, I think that some of the increase has to do with better case finding, but the impact of that is probably quite small. We really are, in fact, seeing many more younger children with eating disorders than we ever have before. Let's just be clear that we don't have a certain explanation for why that has occurred. However, many of us are concerned that, as we have rushed to address the concerns related to obesity in the United States, we have hurried out interventions to try to encourage healthy eating that have, in some vulnerable populations, had unintended consequences.
If you are taught in school that fat is bad and you happen to be a 9-year-old without the cognitive ability to understand the nuances of that information, you are unable to recognize that that's not really a black and white statement. You decide that fat is bad, and you look at every label and, if that food has fat in it, you don't eat it. If you are even more inclined by virtue of an anxiety issue or obsessive compulsive traits to really dig in and grab hold of that way of eating, it doesn't take very long before you get into trouble.
Medscape: The report also noted a wide variance in estimates of prevalence. For example, the report provided estimates of bulimia nervosa ranging from 0.8% to 14%. Can you offer some insight into the reasons behind this variance, and is it related to differences in applying DSM-IV criteria?
Dr. Rosen: The prevalence of anorexia nervosa is fairly well-understood to be about 0.5%. The prevalence of bulimia nervosa is understood to be somewhere in the neighborhood of 2%-4%. Yes, there are some reports that will cite numbers that are quite different from that, but often those reports have very different ways of looking at populations. Sometimes they're looking at particularly vulnerable populations. Sometimes the definitions they are using are a little bit different, and we probably should acknowledge that the DSM-IV criteria are recognized by many as being something less than perfect in capturing the group of kids that do, in fact, have these disorders.
The biggest concern, of course, is the category of "eating disorder not otherwise specified." That has been sort of a "waste basket" for kids who clearly have disordered eating and certainly have all of the associated psychological and medical risks that go along with that, but they don't meet the strict criteria required to be diagnosed with anorexia or bulimia. They get left out of the statistics for anorexia and bulimia, which artifactually reduces the number of kids who are, in fact, affected by eating disorders. The result is that this other category of "not otherwise specified" eating disorders becomes quite large, very heterogeneous, and hard to get your hands around.
It is hoped that the DSM-V criteria, which are going to come out in the next couple of years, are going to help to better classify patients with eating disorders so that we can be more specific about their treatment and reduce the number that have to fall into that unhelpful "not otherwise specified" category.
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Cite this: Eating Disorders in Pediatric Primary Care - Medscape - Jan 11, 2011.