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 study recommends looking beyond body mass index (BMI) to metrics of body composition, such as waist-to-hip and waist-to-height ratios, that better capture where and how fat is stored in the body. —Bret Scher, San Diego Union-Tribune, 5 Feb. 2026

Some of those risk factors include tobacco use, alcohol consumption, high body mass index, insufficient physical activity, air pollution, ultraviolet radiation and infections like hepatitis B, hepatitis C, Epstein–Barr virus and human papillomavirus, or HPV. —Sara Moniuszko, USA Today, 4 Feb. 2026

In the study, researchers reviewed the body mass index of over 11 million Americans across all states. —Dr. Camille Charles, ABC News, 28 Jan. 2026

Reduced Effects of Stress A study of 74 people with higher body mass index (BMI) examined how supplements might affect stress and quality of life. —Amber J. Tresca, Verywell Health, 5 Jan. 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