Mean body weight, height, waist circumference, and body mass index among children and adolescents: United states, 1999–2018

Abstract

Objective—This report presents trends in mean weight, recumbent length, height, waist circumference, and body mass index (BMI) among children and adolescents in the United States from 1999 through 2018. Methods—Data were obtained from physical examinations of nationally representative samples of children and adolescents ranging in age from birth through 19 years in the National Health and Nutrition Examination Surveys during 1999–2018. Means and standard errors for weight (n = 43,321), recumbent length (n = 11,397), height (n = 36,538), waist circumference (n = 35,014), and BMI (n = 36,142) are presented separately for boys and girls, and by single year of age for 4-year survey periods. Trends in body measures over time for continuous 2-year periods by sex and age group (2–5, 6–11, 12–15, 16–19 years) are shown in figures. Trends in mean estimates were evaluated using age-adjusted linear regression. Results—No significant trends over time were observed in any of the body measures for children aged 2–5 years, except for an increase in mean BMI among girls. Among girls aged 6–11, mean height and waist circumference significantly increased from 1999–2000 through 2003–2004, and then significantly decreased for height but remained stable for waist circumference through 2017–2018. Among those aged 12–15, mean body weight and waist circumference increased over time among boys, and BMI increased among both boys and girls. Among adolescent boys aged 16–19, body weight significantly increased from 1999–2000 through 2009–2010 and then significantly decreased through 2017–2018. In addition, height remained stable through 2009–2010 and then significantly decreased through 2017–2018. Among adolescent girls aged 16–19, mean body weight, waist circumference, and BMI significantly increased from 1999–2000 through 2017–2018.