Objectives: It has been recommended that body mass index (BMI) (weight in kilograms/height in meter2) be used routinely to evaluate obesity in children and adolescents. This report describes the distribution of BMI in children and adolescents in the United States.
Methods: Standardized measurements of height and weight from 9 large epidemiologic studies including 66,772 children age 5 to 17 years were used to develop tables for the distributions of BMI that are age, race, and gender specific.
Results: The mean BMI increases with age and is slightly higher for girls than boys. Mean BMI for black and Hispanic girls was noticeably higher than for white girls. The percentiles of BMI are consistently higher than those based on the NHANES I measures, particularly for the 95th percentile. The proportion of obese children compared with NHANES I standards is higher and is highest for Hispanic boys and black and Hispanic girls.
Conclusion: The tables and figures will allow pediatricians to determine the relative ranking of BMI for patients compared with values derived from a large sample of healthy children and adolescents. The identified gender and ethnic differences may be guides to understanding the cause and prevention of obesity.