The 2000 & 2022 CDC Growth Chart Reference Population
The reference population used to construct the CDC Growth Charts for children aged 2 years to 20 years is a nationally representative sample.
Data Used to Create the 2000 CDC Growth Charts
- Child and Adolescent Data in the CDC Growth Chart ReferenceData used to create the growth charts for children and teens aged 2 years to 20 years were nationally representative and obtained from 5 national survey data sets (Kuczmarski et al., 2000).Data for the 2000 CDC Growth Charts included:
- physical measurements of height (also referred to as stature) and weight from children and teens 2 years to 20 years of age.
The measurement data were obtained from a series of national health examination surveys conducted by the National Center for Health Statistics (NCHS) from 1963 to 1994. These surveys and data sources included:
- National Health Examination Survey (NHES), Cycle II (1963-65; ages 6-11y)
- National Health Examination Survey (NHES), Cycle III (1966-70; ages 12-17y)
- National Health and Nutrition Examination Survey (NHANES) I (1971-74; ages 2-19 y)
- National Health and Nutrition Examination Survey (NHANES) II (1976-80; ages 2-19 y)
- National Health and Nutrition Examination Survey (NHANES) III (1988-94; ages 2-19 y for stature, ages 2-5 y for weight and BMI)
In each of the cross-sectional surveys, a national probability sample of the civilian, non-institutionalized population of the United States was examined. Survey-specific sample weights were applied to the national survey sample data to assure representation of the U.S. population according to age, sex, and racial/ethnic composition at the time the surveys were conducted.
Exclusions from the Growth Reference Population
- NHANES III (1988-1994) Weight Data for Children Aged 6 Years and Older
NHANES III data were excluded because of an upward shift in the weight-for-age and BMI-for-age curves given population level changes in body weight that occurred in the 1980s and 1990s (Kuczmarski et al., 2002). If data from NHANES III had been included, the resulting 95th percentile curve would have been higher, thus classifying fewer children and teens as having obesity.
Data Used to Create the 2022 CDC Extended BMI-for-age Growth Charts
BMIz values above the 95th percentile (i.e., extended BMIz values) are based on a dataset of 8,777 children and adolescents with obesity (1,814 [21%] from the 2000 CDC growth chart reference population and 6,963 [79%] from NHANES III and NHANES 1999-2016). These data were used to model BMI distribution above the 95th percentile as half-normal distributions by sex and within 6-month age groups.
The racial and ethnic distribution in the reference population is representative of the U.S. population at the time each of the NHES and NHANES surveys were conducted.
CDC has one set of growth charts for use in all racial and ethnic groups of US children.