Among US youth, differences in adiposity by race/Hispanic origin were analyzed and it was also investigated how those differences are associated with differences in body mass index (BMI). Findings demonstrated that disparities in %BF (percentage body fat) and FMI (fat mass index) by race/Hispanic origin were not consistent by BMI category among US youth in 2011–2018.

• Relevant data were obtained from 6,923 youth 8–19 years in the National Health and Nutrition Examination Survey (NHANES) 2011–2018.

• In Hispanic males (28.2%) and females (35.7%), the observed %BF was highest.

• A lower %BF was found among non-Hispanic Black (23.9%) vs non-Hispanic White (26.0%) and non-Hispanic Asian (26.6%) males.

• No difference existed between non-Hispanic Black females (32.7%) and non-Hispanic White (33.2%) or non-Hispanic Asian (32.7%) females.

• Hispanic youth had higher FMI than non-Hispanic White youth.

• Among youth with underweight/healthy weight, predicted %BF and FMI were found to be lower in non-Hispanic Black males and females, vs non-Hispanic White youth, and were identified to be higher in Hispanic males and females, while non-Hispanic Asian males and females exhibited higher %BF but not FMI.

• In the female population with obesity, lower %BF and FMI were present in non-Hispanic Asian females vs non-Hispanic White females.