# Body Mass Index (BMI): What You Need to Know

## What is Body Mass Index (BMI) and how is it calculated?

Choose the correct option:

A) A percentage of body weight.

B) A measure of body density.

C) The ratio of a person's body weight to his or her height squared.

D) The ratio of a person's height to the square of his or her body weight.

Final answer:

## Answer:

Body Mass Index (BMI) is the ratio of a person's weight to the square of their height, used as a screening tool for categorizing weight status, but it has limitations as it doesn't measure body composition directly.

The Body Mass Index (BMI) is a widely used screening tool to categorize individuals based on body size, which estimates the fat content of the body. It is essential to note that BMI is not a direct measure of body fatness or composition. BMI is calculated by dividing a person's weight in kilograms by the square of their height in meters. The formula is: BMI = weight (kg) / [height (m)]2 for the metric system, and 703 x weight (lbs) / [height (in)]2 for the imperial system. The resulting value is then evaluated against standard categories: a BMI less than 18.5 is considered underweight; a BMI between 18.5 to 24.9 is normal; between 25 to 29.9 is considered overweight; and a BMI of 30 or higher is classified as obese.

Despite its widespread use, there are limitations to BMI, as it does not account for differences in muscle mass, bone density, overall body composition, and racial and ethnic differences in body type.