Body Mass Index (BMI)

Body mass index, or BMI, is a measurement of your weight in relation to your height and is used to gauge your percentage of body fat. The formula for assessing your BMI involves dividing your weight in kilograms by your height in meters squared (kg/m²). To do this, multiply your weight in pounds by 703, then divide that number by your height in inches, then take that answer and divide it by your height in inches again. The resulting number is your BMI. If you’re not a math enthusiast, don’t worry. You can just use the BMI calculator here.

A healthy BMI falls between 18.5 and 24.9. You are considered overweight if your BMI is between 25 and 30, and obese if it is 30 or higher. Extreme obesity is defined as a BMI of 40 or greater.

More About BMI Richard W. Bock, MD Play QuickTime Play Windows Media

Other tests
In addition to the percentage of body fat you have, some experts emphasize the importance of where this fat is distributed and stored in the body. Studies have shown that when fat is stored around the abdomen, you are more likely to develop hypertension, cardiovascular disease and diabetes than if the majority of your fat is stored in the lower part of your body. You may have heard of this in terms of apple- or pear-shaped people. In this analogy, pear-shaped people, who store fat in the lower half of their bodies, have less risk of developing serious health complications from obesity than apple-shaped people, who store excess fat around their waist.

One of the ways to determine your risk based on abdominal fat is to consider your waist circumference. Men who have a waist circumference greater than 40 inches and women who have a waist circumference greater than 35 inches are at increased risk for heart disease and other obesity-related problems.

Another way you can evaluate your health risk based on fat distribution is to determine your waist-to-hip ratio. Divide your waist circumference in inches by your hip measurement in inches (the widest point around your hips and buttocks). A healthy waist-to-hip ratio for men is less than 0.9, and for women less than 0.8.