Teens who were once overweight or obese are at a significant risk of developing an eating disorder as they lose weight, but identification and treatment of the condition is often delayed because of their weight history, researchers say.
"For some reason we are just not thinking that these kids are at risk. We say, 'Oh boy, you need to lose weight, and that's hard for you because you're obese,' " says Leslie Sim, clinical director of the eating disorders program at the Mayo Clinic in Minnesota and lead author of a case study report in October's Pediatrics, published online today.
In the report, Sim and colleagues review two cases in which teens with a history of obesity developed severe, restrictive eating patterns in the process of losing weight. But indications of an eating disorder went unidentified and untreated by medical providers for as long as two years despite regular check-ups.
Symptoms for one, a 14-year-old boy, included concentration problems and irritability, cold intolerance, bloating and chest pains. A girl, 18, had stress fractures, menstrual problems, hair loss and dizziness, among other problems. Physicians attributed the symptoms to rarer disorders, such as gastrointestinal conditions or polycystic ovary syndrome, says the report.
Both teens "set out to diet, and were both very diligent, eating fewer than 1,500 calories a day, running and doing other intense activities to lose weight in a very driven way," says Sim. Each lost a "massive amount of weight very quickly. They were not binging, not throwing up. It was simply from having a very low-(calorie) intake."
About 6% of youths suffer from eating disorders, according to a 2011 study in the Archives of General Psychiatry, cited in the report. It also cites CDC figures that 55% of high school girls and 30% of boys report "disordered eating symptoms" to lose weight, such as diet pills, vomiting, laxatives, fasting and binge-eating.
Eating disorders have the highest mortality rate of any mental health illnesses, and successful treatment requires medical, psychiatric and nutritional intervention, says Sim, a child psychologist.
At the Mayo Clinic, about 35% of kids and teens who come in for a restrictive eating problem have a history of having been overweight or obese, she says. That may be reflected nationally, Sim says: Government statistics estimate that about 30% of kids and teens are overweight or obese.
That it takes so long to recognize the eating disorder risk for kids with a history of obesity is particularly concerning, given that "the best prognosis for recovering from an eating disorder is catching it early," she says.
The cases cited in Pediatrics mirror a trend that psychiatrist Jennifer Hagman has been seeing "with much more prevalence" over the past five years.
It's a "new, high-risk population that is under-recognized," says Hagman, medical director of the eating disorders program at Children's Hospital Colorado, who was not involved in the new report.
The kids she sees in this condition "are just as ill in terms of how they are thinking" as they are in terms of physical ailments, she says. "They come in with the same fear of fat, drive for thinness, and excessive exercise drive as kids who would typically have met an anorexia nervosa diagnosis. But because they are at or a even a little bit above their normal body weight, no one thinks about that."
These cases are no surprise, says Lynn Grefe, president of the National Eating Disorders Association. "Our field has been saying that the more we're pushing the anti-obesity message, the more we're pushing kids into eating disorders" by focusing on size or weight instead of health and wellness.
The exact relationship between pediatric obesity and eating disorders is not well-understood, says Melinda Sothern, a pediatric obesity and physical activity researcher at Louisiana State University Health Sciences Center. "More studies are needed to determine the risk profile for disordered eating in obese children seeking treatment."
A larger public health problem "is the lack of mental health and emotional medical support for children with especially severe obesity," Sothern says.
The No. 1 risk factor for developing an eating disorder is dieting, says Sim. "I've never seen an eating disorder that didn't begin with a conscientious effort to diet."
The problem here is that "when a child is obese and starts to lose weight, we think it's a really great thing and we applaud it and reinforce it and say it's so wonderful and now you're healthy," says Sim. Meanwhile, some kids are "very unhealthy, with many physical and psychological problems as a result of their behaviors. They are just not being identified because of their weight history."
It's essential, she says that eating-disorder symptoms be on every medical provider's radar, regardless of the patient's weight, and that providers monitor any weight loss that deviates from a child's growth pattern, paying close attention to how the weight change occurred.