June 18, 2024

Summary and References: Using BMI-for-Age Growth Charts

The American Academy of Pediatrics recommend that U.S. health care providers screen the weight status of children and adolescents at least annually. CDC offers growth charts, extended growth charts, and a Body Mass Index (BMI) Calculator to help monitor the growth of children and adolescents 2 years and older.

Health care provider holding a tablet and talking with a family of parents and their child.

Summary

Annual assessment of BMI is recommended for all children and adolescents 2 years or older.
For children and adolescents 2 years or older, BMI is age- and sex-specific.
Sex-specific BMI-for-age is a screening measure. It provides an opportunity for health care providers to talk with patients and their families about growth.
BMI categories are defined based on age- and sex-specific percentiles:
- Underweight (BMI less than 5th percentile).
- Healthy weight (BMI greater than or equal to 5th and less than 85th percentile).
- Overweight (BMI greater than or equal to 85th and less than 95th percentile).
- Obesity (BMI greater than or equal to 95th percentile).
- Severe obesity (BMI greater than or equal to 120% of the 95th percentile or BMI greater than or equal to 35 kg/m²). Severe obesity is a subset of obesity.
When monitoring BMI for children and adolescents 2 years or older:
- Use the 2000 CDC BMI-for-Age Growth Charts if BMI is at or below the 95^th' percentile.
- Use the CDC Extended BMI-for-Age Growth Charts if BMI is above the 97^th percentile.
- Either growth chart can be used for BMIs between the 95^th and 97^th percentile.

Online calculator‎

CDC's Child and Teen BMI Calculator generates the BMI category and BMI percentile for children and adolescents 2 through 19.

Glossary

Anthropometric index: measure that combines height, weight, or body mass index with age. BMI-for-age is an example of an anthropometric index.

Adiposity: also known as body fatness. It is the amount of body fat, expressed either as total fat mass (in kilograms) or the fraction (percentage) of total body fat.

BMI-for-age: an anthropometric index of weight and height combined with age.

Healthy weight: for children and adolescents 2 to 20, healthy weight is defined as sex-specific BMI-for-age greater than or equal to the 5th and less than the 85th percentile.

Height: also referred to as stature. It is the distance from the crown of the head to the surface on which the individual is standing when not wearing shoes. Height is used in calculations for children and adolescents 2 to 20.

Length: the correct linear measurement for infants younger than 2 years or children 2 to 3 years who cannot stand unassisted. Length is measured in the recumbent (lying) position.

Obesity: defined as sex-specific BMI-for-age greater than or equal to the 95th percentile in children and adolescents 2 to 20.

Overweight: defined as sex-specific BMI-for-age greater than or equal to the 85th and less than the 95th percentile in children and adolescents 2 to 20.

Severe obesity: defined as BMI greater than or equal to 120% of the 95th percentile for sex and age or BMI greater than or equal to 35 kg/m2 in children and adolescents 2 to 20. Severe obesity is a subset of obesity.

Sex: refers to sex assigned at birth (male or female). In CDC growth charts, the term "boys" refers to males, and "girls" refers to females.

Stature: see height.

Stature-for-age: an anthropometric index that describes linear growth relative to age. Stature- or length-for-age is used to define shortness or tallness.

Underweight: defined as sex-specific BMI-for-age less than the 5th percentile in children and adolescents 2 to 20.

Weight-for-age: an anthropometric index of body weight relative to age. It might be influenced by recent changes in health or nutritional status. It can help explain changes in BMI-for-age in some children and adolescents.

Z-score: in a standard normal distribution, the z-score represents the number of standard deviations away from the population mean. It indicates the degree to which a person's measurement deviates from what is expected.