Anthropometric Indices: Definitions and Categories
Weight and height (also referred to as stature) are commonly used to assess growth of children and teens aged 2 to 20 years. When weight, height, or body mass index (BMI) is combined with age, the result is an anthropometric index. The CDC Growth Charts for children and teens aged 2 to 20 years reflect three anthropometric indices that are sex- and age-specific.
Stature-for-age describes linear growth relative to age. Stature- or length-for-age is used to define shortness or tallness.
Weight-for-age reflects body weight relative to age and might be influenced by recent changes in health or nutritional status. It is not used to classify children and teens as having underweight or overweight. However, it can be important to help explain changes in BMI-for-age in some children and teens.
BMI-for-age reflects body mass index relative to age. BMI is a measure of weight that is adjusted for height. BMI-for-age percentile is classified into the following categories: underweight, healthy weight, overweight, obesity, or severe obesity.
Child BMI Categories
Percentiles are used to rank the position of an individual by indicating what percent of the reference population the individual would equal or exceed. Using sex- and age-specific percentiles to define BMI and stature categories in children is important because they are still growing.
The definitions of BMI categories are listed below:
|< 5th Percentile
|5th Percentile to < 85th Percentile
|≥ 85th Percentile to < 95th Percentile
|≥ 95th Percentile
|≥ 120% of the 95th Percentile or ≥ 35 kg/m2
Read more about current obesity prevalence estimates for US children and teens.
- BMI-for-age is an anthropometric index that reflects body mass index relative to age.
- Percentiles are used to rank the position of a person by indicating what percent of the reference population the person would equal or exceed.