body mass index

noun

: a measure of body fat that is the ratio of the weight of the body in kilograms to the square of its height in meters

Examples of body mass index in a Sentence

A person with a body mass index of more than 30 is considered to be obese.

Recent Examples on the Web

The groups were matched across age, race, ethnicity, body mass index, breast density and diabetes status. — Ken Alltucker, USA Today, 2 June 2026

People with a balanced gut microbiome are more likely to have a healthy body mass index (BMI). — Carrie Madormo, Verywell Health, 11 June 2026

While long-term studies are still limited, one study of children with autism who took nightly prolonged-release melatonin for two years found no significant changes in body mass index or puberty timing. — Sally Ibrahim, The Conversation, 23 June 2026

The disease is often associated with severe obesity, defined by a body mass index (BMI) of 40 or higher. — Alisha Ebrahimji, CNN Money, 30 June 2026

Word History

First Known Use

1983, in the meaning defined above

Kids Definition

body mass index

noun

: a measure of body fat that is the ratio of the weight of the body in kilograms to the square of its height in meters

Medical Definition

body mass index

noun

: a measure of body fat that is the ratio of the weight of the body in kilograms to the square of its height in meters

a body mass index in adults of 25 to 29.9 is considered an indication of overweight, and 30 or more an indication of obesity

—abbreviation BMI

called also Quetelet index