Mona Sharifi

Objective This study aimed to examine the extent to which Bright Bodies, a high‐intensity, family‐based pediatric weight management intervention, improved BMI for participants since publication of the randomized controlled trial establishing efficacy in 2007 and to describe adaptations to the program. Methods For participants enrolled from 2008 to 2018, linear mixed‐effects models were used to estimate monthly change in BMI expressed as percentage of the 95th percentile (%BMIp95) during participants' first beginner‐level program. Results The sample included 396 youth individuals (mean age: 11.7 [SD 2.8] years, 61.6% female, 37.1% non‐Hispanic Black, 26.3% Hispanic or Latino, 53.8% with public insurance, 80.1% with severe obesity). Across the 11 years, participants' %BMIp95 reduced on average by 1.63% (95% CI: 1.44%‐1.82%) per month during their first program (mean duration: 10 weeks) after adjusting for age, sex, season and year, starting %BMIp95, race and ethnicity, and insurance category. Greater reduction in %BMIp95 was associated with male versus female sex, spring/fall versus winter seasons, enrollment in 2008 to 2018 versus 2015 to 2018, and higher starting %BMIp95 ( p value for all <0.001). Adaptations since 2007 included pragmatic changes to increase engagement and address funding shortages. Conclusions These results suggest sustained clinical effectiveness of Bright Bodies in the context of real‐world adaptations.