CP Research Corner: childhood BMI as a risk factor

Persistent, significantly low or high body weight in children found to be linked to increased risk of eating disorders later on.

A study published in the February 2019 issue of the Journal of the American Academy of Child and Adolescent Psychiatry, found that persistent low body mass index (BMI) in children – as early as age two for boys and four for girls – may be a risk factor for the development of anorexia nervosa in adolescence. The study also found that a consistently high BMI in these early years may be a risk factor for the development of bulimia nervosa, binge-eating disorder and purging disorder later in life.

While eating disorders have long been understood to be caused by a confluence of psychological, social, cultural and environmental factors, this study highlights that there are metabolic factors at play as well.  The researchers hypothesize that veering off course in terms of weight (either below or above the normal range) may either trigger a biologically-based vulnerability to developing an eating disorder or else, the weight irregularity may be an early manifestation of an illness that further develops over the course of years.

This study’s findings are particularly helpful since early intervention in eating disorders is so essential for successful treatment.  It’s standard for height and weight to be recorded for children at every yearly well-visit.  For those children plotting consistently and significantly below or above the norm on their weight/growth curves, pediatricians can recommend interventions that could potentially change the course for children at risk.


Zeynep Yilmaz, Nisha C. Gottfredson, Stephanie C. Zerwas, Cynthia M. Bulik, Nadia Micali. Developmental Premorbid Body Mass Index Trajectories of Adolescents With Eating Disorders in a Longitudinal Population CohortJournal of the American Academy of Child & Adolescent Psychiatry, 2018; DOI: 10.1016/j.jaac.2018.11.008