|  | Diet Nutrition | Healthy Diets

What Does BMI Stand for & What Does It Tell Us?

BMI stands for body mass index, a measure doctors commonly use to determine whether a person has a healthy body weight. Rather than relying solely on the numbers on the scale, BMI takes into account both height and weight, so two people of the same weight could have very different BMIs. This same weight could also mean vastly different things; one person might be underweight while another might be overweight.

  1. Information on BMI

    • Your body mass index is actually just a ratio of body weight and height. There's no single "right" weight for everyone, so BMI calculations provide a range of healthy weights rather than a single recommended weight. Although your BMI can be used in conjunction with your waist circumference to estimate your body fat, BMI is not a measure of your body fat percentage, and some people with high BMIs may have low body fat percentages.

    BMI Calculation

    • You can calculate your body mass index by squaring your height in inches, then dividing your weight in pounds by this number. Multiply the number by 703 to arrive at your result. Normal BMI is between 20 and 24, while people with BMIs under 20 are underweight. If your BMI is above 24, you are considered overweight, and obesity is a BMI of 30 or higher. Some medical professionals also measure "extreme obesity," which is defined as a BMI above 40.

    Effects of BMI

    • A high BMI correlates with a number of negative health effects, including a strong correlation with diabetes. A 2007 study published in the "American Journal of Health Promotion" also found a correlation between a high BMI and an increase in joint injuries. Doctors sometimes use BMI to determine whether a patient needs to lose or gain weight, and insurance companies may use it to predict disease risk.

    Criticisms of BMI

    • Because BMI is based upon weight, it can't differentiate between healthy and unhealthy weight. A person with a very high muscle mass could actually register as obese on a BMI scale, even though he was at a healthy weight and had a low body fat percentage. Not all researchers agree with the use of BMI to diagnose illness. Nutritionist Linda Bacon, for example, emphasized that people can be healthy even if they are overweight in her book, "Health at Every Size."

Healthy Diets - Related Articles