Body Mass Index Categories of Transgender and Gender Diverse Youth: Clinical Associations and Predictors.

Background: Transgender/gender diverse (TGD) youth are at risk for weight-related problems. We describe factors associated with their body mass index (BMI) category. Methods: Chart review of 228 TGD patients, 12-20 years ( u  = 15.7, standard deviation 1.3), 72% female assigned at birth. BMI percentile was calculated using CDC growth charts. We examined bivariate relationships of 18 clinically derived factors, utilizing analysis of variance (ANOVA) for continuous variables and chi-squared/Fisher's exact test for categorical variables. Nonparametric Classification and Regression Tree (CART) analyses were used to predict BMI category. Results: Almost half (49.6%) of TGD youth presenting for their initial visit for pediatric gender-affirming care fell in the healthy weight range, 4.4% in the underweight range, 16.7% in the overweight range, and 29.4% in the obese range. Self-described weight, weight management intentions, unhealthy weight management, prescription of psychiatric medications, and medications associated with weight gain were associated with BMI category. Use of psychiatric medications (54.8%) and medications associated with weight gain (39.5%) was associated with BMI in the overweight/obese categories. Youth with obesity most often reported unhealthy weight management. In CART models, self-described weight was the strongest predictor of BMI category. Conclusion: TGD youth have high rates of underweight and overweight/obesity. Unhealthy BMI should be treated as part of gender-affirming care. Self-described body weight is associated with weight category. More than half of TGD youth were prescribed psychiatric medications; those with overweight and obesity were more likely prescribed psychiatric and medications with associated weight gain. Youth with obesity were most likely to use unhealthy weight management.