BackgroundThe growing body of research on eating disorders among male adolescents reveals some sex differences in clinical presentation. The current study set out to replicate and extend recent research on the clinical and medical characteristics of male youth with eating disorders, and examine sex differences between biological males and females in a tertiary pediatric eating disorder treatment setting.MethodsA retrospective chart review was conducted with all biological males who were admitted to the Eating Disorders Programs at British Columbia Children’s Hospital (2003–2015) or the Looking Glass Residence (2011–2015). Clinical data, including demographics, percentage of median body mass index (% mBMI), and psychiatric diagnoses, were recorded along with medical data (i.e., vital signs, basic biochemistry investigations, and bone mineral density). A comparison group of females with eating disorders who received treatment at British Columbia Children’s Hospital in the inpatient or outpatient streams (2010–2015) were included, to examine sex differences with males who were admitted during the same period.ResultsA total of 71 male youth were included in the chart review. Males had significant medical complications, with 26.5% of the sample presenting with a heart rate of less than 50 beats per minute and 31.4% presenting with a bone mineral density z-score for the lumbar spine ≤ − 1. Sex differences between the subset of males who were treated between 2010 and 2015 (n = 41) and the females (n = 251) were examined. Females were more likely than were males to have a diagnosis of anorexia nervosa or bulimia nervosa, and to be underweight (< 95% mBMI) at admission. Males were younger than females, but no differences emerged in the duration of the eating disorder symptoms. No sex differences emerged relating to medical instability (e.g., bradycardia).ConclusionsA large proportion of male children and youth with eating disorders are medically compromised at admission. Males were younger than females, and were less likely than females to have a diagnosis of anorexia nervosa or bulimia nervosa. Males who were underweight at admission had also lost a lower percentage of body weight in comparison to females. The current study replicates previous sex differences reported in pediatric samples.