Glossary
Anthropometric Index: measurement that combines height, weight, or other proportions of the human body; BMI-for-age is an example of an anthropometric index
Adiposity: also known as body fatness; the amount of fat in the body, 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. Sex-specific BMI-for-age percentiles are used to classify BMI category (underweight, healthy weight, overweight, obesity, severe obesity) in children and teens aged 2 to 20 years
Healthy Weight: defined as sex-specific BMI-for-age ≥ 5th and < 85th percentile in children and teens aged 2 to 20 years
Height: also referred to as stature; distance from the crown of the head to the surface on which the individual is standing when they are not wearing shoes; measured for children and teens aged 2 to 20 years
Length: the correct linear measurement for infants aged < 2 years or children aged 2 to 3 years who cannot stand unassisted; measured in the recumbent position
Obesity: defined as sex-specific BMI-for-age ≥ 95th percentile in children and teens aged 2 to 20 years
Overweight: defined as sex-specific BMI-for-age ≥ 85th and < 95th percentile in children and teens aged 2 to 20 years
Severe obesity: defined as BMI ≥ 120% of the 95th percentile for sex and age or BMI ≥ 35 kg/m2 in children and teens aged 2 to 20 years; 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 < 5th percentile in children and teens aged 2 to 20 years
Weight-for-age: an anthropometric index of body weight relative to age. It might be influenced by recent changes in health or nutritional status, and can be important to help explain changes in BMI-for-age in some children and teens.
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 for that person.