Do you know your BMI? Do you even know what it is, other than an acronym that keeps popping up in magazines, doctor's offices and websites? Created in the 19th century by a Belgian mathematician, the body mass index has been used for years as a baseline weight range, health and fitness indicator. Now, however, BMI is being looked at more closely for its relation to health concerns.
What It Is
BMI is the number calculated from the ratio of your height and weight. This calculation helps determine if your weight is healthy for your height. It is also a good tool for evaluating how much body fat is present. While BMI doesn't measure body fat directly, it is an accessible alternative and easy for most people to calculate on their own. BMI is a better indicator of potential health and disease problems and risk factors than just looking at weight.
Calculations
For men and women over 20, BMI is calculated using this formula: weight in pounds divided by height in inches squared multiplied by 703. So for someone who weighs 150 lbs. and is 5 foot, 5 inches tall, that would be 150 divided by 4,225 multiplied by 703, which equals 24.96.
BMI numbers fall into the following categories: Below 18.5 is underweight; between 18.5 and 24.9 is the normal/healthy range; between 25 and 29.9 is overweight; between 30 and 39.8 is obese; and over 40 indicates extremely or morbidly obese.
Health Concerns
As the amount of body fat and weight increases, the risk of a serious health condition increases, too. A BMI under 25 has a minimal risk for diseases like type 2 diabetes and hypertension, a BMI between 25 and 29.9 carries a moderate risk and those with a BMI over 30 carry a high risk. Carrying excess weight and body fat puts strain on the heart and can also lead to heart disease, osteoarthritis, stroke, sleep apnea and varicose veins.
Considerations
As the Centers for Disease Control and Prevention states, BMI is not a diagnostic tool and should be considered one tool of many to determine overall health state. A doctor can determine if excess weight is a risk by performing other tests and screenings, like a skinfold test, and evaluating diets and family history. There are some discrepancies in age and gender when it comes to the BMI number and the amount of body fat. For example, even with the same BMI score, a woman tends to have more body fat than a man.
Exceptions
While BMI is an easy tool for evaluating health, it is not for everyone. Women who are pregnant or nursing should not use BMI in relation to health concerns, as the result may be out of the "normal" range with due cause. Athletes and those with a more muscular build will show a high BMI since they have more muscle. People in these groups should discuss other health risk evaluation methods with their doctor. The elderly should talk to their doctor about a healthy BMI level, as sometimes it is better to have a higher BMI to protect from osteoporosis.
Member Comments