Obese teenagers who lose weight are at greater risk of developing eating disorders such as anorexia nervosa and bulimia nervosa, a sign that there may be a psychology issue regarding their relationship to food.

But because weight loss is a healthy positive to both doctors and family members, eating disorders may not be adequately detected.  Up to 6 percent of American adolescents suffer from eating disorders, and in surveys more than 55 percent of high school females and 30 percent of males claim disordered eating symptoms including engaging in one or more maladaptive behaviors (fasting, diet pills, vomiting, laxatives, binge eating) to induce weight loss.

Although not widely known, individuals with a weight history in the overweight (BMI-for-age greater than or equal to the 85th percentile but less than the 95th percentile, as defined by CDC growth chart) or obese (BMI-for-age greater than or equal to the 95th percentile, as defined by the CDC growth chart) range, represent a substantial portion of adolescents presenting for eating disorder treatment.

In a new paper, Mayo Clinic researchers argue that formerly overweight adolescents tend to have more medical complications from eating disorders and it takes longer to diagnose them than kids who are in a normal weight range, says Leslie Sim, Ph.D., an eating disorders expert in the Mayo Clinic Children’s Center and lead author of the article. “Given research that suggests early intervention promotes best chance of recovery, it is imperative that these children and adolescents’ eating disorder symptoms are identified and intervention is offered before the disease progresses.” 

They analyze two examples of eating disorders that developed in the process of obese adolescents’ efforts to reduce their weight. Both cases illustrate specific challenges in the identification of eating disorder behaviors in adolescents with this weight history and the corresponding delay such teenagers experience accessing appropriate treatment.

Eating disorders are associated with high relapse rates and significant impairment to daily life, along with a host of medical side effects that can be life-threatening, says Sim.

Published next week in Pediatrics.