When obese teenagers lose weight, family and friends usually look at this as a positive improvement for their health. But new research from the Mayo Clinic shows that overweight teens who lose weight can also be at risk of developing anorexia nervosa or bulimia nervosa.

The findings, published online in the journal Pediatrics, reveal that the positive reactions from friends, family and even medical professionals may be the very reason such eating disorders are not detected at an earlier stage.

Two cases of formerly overweight teens were presented in the study:

  1. A 14-year-old boy who lost 87 pounds in 2 years
  2. An 18-year-old girl who lost 83 pounds in 3 years, going from the 97th percentile for body mass index (BMI) to the 10th percentile.

In the first case, the boy’s attempts to exercise and eat healthfully quickly turned into “severe restriction.” Although he lost more than half his body weight, the study’s authors say that his medical notes did not point to an eating disorder concern until his mother asked for an evaluation.

In the second case, the girl’s mother worried about her daughter’s low fat intake and eating habits, but doctors overlooked her concerns, writing off the teen’s lack of menstrual period and dizziness as dehydration or maybe even polycystic ovary syndrome (PCOS).

In both cases, although the teens underwent regular medical examinations and showed “obvious signs of malnutrition,” their eating disorders were not diagnosed and they worsened as a result.

Dr. Leslie Sim, an eating disorders expert from the Mayo Clinic and lead author of the study, says that early intervention is key when it comes to eating disorders:

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.”

According to the study’s authors, at least 6% of adolescents have an eating disorder, and more than 55% of high school girls and 30% of boys report disordered eating habits to lose weight, such as fasting, using diet pills, vomiting, using laxatives or binge eating.

2 ladies standing back-to-back, one heavier than the otherShare on Pinterest
Formerly overweight or obese teens who develop eating disorders, such as anorexia or bulimia, are not diagnosed as quickly as their peers in a normal weight range.

Dr. Sim notes that eating disorders carry high relapse rates and come with medical side effects that can be life-threatening. When undiagnosed – particularly in the cases of formerly overweight kids – the side effects of eating disorders can bring even more medical complications.

The study’s authors write that though it is not widely known, a “substantial portion” of adolescents who are seen for eating disorders treatment have a weight history in the overweight or obese percentile, as defined for the Centers for Disease Control and Prevention (CDC).

According to the CDC, being overweight is defined as being between the 85th and 95th percentile for BMI in your age group, while obesity is defined as being over the 95th percentile.

The authors conclude the study by noting that any weight loss (even if it brings the child into the “average” range) should merit eating disorder screening. Regardless of the patient’s weight, they say, every clinician should be on the lookout for symptoms of eating disorders.