A child need not look underweight for rapid weight loss to signal anorexia

Paediatricians are urging clinicians and parents to focus on sudden changes in a child’s growth trajectory and other warning signs, rather than relying on body size to identify eating disorders.

At an American Academy of Pediatrics conference in San Diego, paediatricians urged clinicians and parents to look beyond body size when watching for eating disorders in children and teenagers. A rapid drop in weight, even when a child remains in a higher percentile for age, can be a warning sign that something is seriously wrong.

Michelle Odette, a paediatrician at the University of California, San Francisco, said clinicians should not wait for obvious thinness before screening. She and colleague Marissa Raymond-Flesch pointed to cases in which children lost substantial weight over a short period and were initially easy to overlook because they did not appear underweight.

Raymond-Flesch said one of the biggest pitfalls is assuming anorexia nervosa only affects children with a very low weight. In atypical anorexia nervosa, a child meets the behavioural and psychological criteria for anorexia but does not fall below the expected weight range. That means a young person may still sit at a seemingly healthy percentile while their own growth curve has shifted sharply downward. Experts note that clinicians should pay close attention to changes in a child’s usual trajectory, not just the number on the scale.

That distinction matters because atypical anorexia can be medically dangerous. The Cleveland Clinic and the National Eating Disorders Association both say the condition is often under-recognised because of weight bias and the persistent belief that an eating disorder must involve being underweight. Research cited by those groups suggests the disorder is not rare and that more patients are ending up hospitalised as cases are missed. The American Academy of Pediatrics also says restrictive eating can be subtle and may go unnoticed by families and doctors.

Odette said other red flags include a slow heart rate in a young athlete, fatigue, dizziness, trouble concentrating and menstrual changes. She also advised clinicians to ask about GLP-1 weight-loss drugs if there is unexplained rapid weight loss or if these medicines are present in the home, because some young people may use them improperly or access them through relatives. Cynthia Bulik, a nutrition professor at the University of North Carolina at Chapel Hill, said weighing a child can be a useful chance to ask how they feel about their body and whether the scale itself is causing distress.

Both experts said early recognition is critical because treatment outcomes improve when the disorder is addressed promptly. Raymond-Flesch said family-based treatment has the strongest evidence for children and adolescents with anorexia nervosa and atypical anorexia nervosa, and that the approach can work even when the child does not look underweight.