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

Strikingly, at the end of 80 weeks, about six out of 10 participants in the 12-mg group were no longer considered to have obesity based on their body mass index, according to Eli Lilly. — Jackie Flynn Mogensen, Scientific American, 29 Sep. 2026

During sign out, when doctors tell each other about patients at shift change, body mass index was a constant source of eye rolls and jokes. — Jessica Rosenblum, STAT, 8 Sep. 2026

The scientists followed participants for up to 14 years and examined how changes in body mass index, or BMI, and waist circumference were associated with the risk of death. — Faye Chiu, CNN Money, 26 Aug. 2026

Under the pilot, many Medicare beneficiaries with a body mass index of 35 or higher — the upper range of obesity — qualify for coverage of one of those drugs, if prescribed. — Jackie Fortiér, Miami Herald, 25 Aug. 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