Percent Body Fat and Weight Status of Youth Participating in Pediatric Weight Management Programs in the Pediatric Obesity Weight Evaluation Registry.

Factors associated with change in percent body fat (%BF) of children in pediatric weight management (PWM) care may differ from those associated with change in weight status. Objective: To describe %BF and weight status at initial visits to 14 PWM sites, identify differences by sex, and evaluate factors associated with change over 6 months. Methods: Initial visits of 2496 males and 2821 females aged 5-18 years were evaluated. %BF was measured using bioelectrical impedance analysis. Results: Sex-specific logistic regressions [806 males (32.3%), 837 females (29.7%)] identified associations with primary outcomes: lower %BF and metabolically impactful ≥5-point drop in percent of the 95th BMI percentile (%BMIp95) over 6 months. At the initial visit, males had lower %BF and higher %BMIp95 than females. Over 6 months, males had significantly (p < 0.001) greater median drop in %BF (-1.4% vs. -0.4%) and %BMIp95 (-3.0% vs. -1.9%) and a higher frequency of decreased %BF (68.9% vs. 57.8%), but similar percentage with ≥5-point %BMIp95 drop (36.5% vs. 32.4%; p = 0.080). For males, factors significantly associated with decreased %BF (older age, ≥6 visits, lack of developmental or depression/anxiety concerns) were not related to having a ≥5-point %BMIp95 drop. For females, lack of depression/anxiety concern was significantly associated with decreased %BF but was not associated with ≥5-point %BMIp95 drop. Conclusions: There are differences by sex in initial visit %BF and %BMIp95 and in characteristics associated with changes in these measures. PWM interventions should consider evaluating body composition and sex-stratifying outcomes.