A Way to Gauge Your Physical Stature

Nowadays it’s nearly impossible to open up a health or fitness magazine without finding the term “BMI” peppered throughout the pages willy-nilly. “It’s downright trendy,” says Paul Cummings, M.D., an Internal Medicine Hospitalist and Site Director for Legacy Emanuel Hospital in Portland, Ore. But is it just another temporary health fad that will go the way of the Atkins Diet, or is this BMI business a trend that’s here to stay? Well, first you have to understand what it is.

Body Mass Index (BMI) is a way of measuring body fat based on height and weight that applies to all adults. It is usually derived by dividing the weight in kilograms by the square of the height in meters, but can also be determined by pounds and inches. A BMI of 18.5 to 24.9 is considered normal, while under 18.5 is considered underweight, 25–29.9 is considered overweight and 30 or greater is considered obese. In other words, it isn’t a trend at all but rather just a tool for determining if you’re in a healthy weight range for your height, if you are too thin or if you are too big. It’s easy for people to say that an extra five In-N-Out-induced pounds is no big deal, but your BMI will tell you definitively that you’re wrong.

The reason that you should care is that a high BMI (essentially excessive body fat or obesity) has been linked with greater incidence of disease and death. According to the American Heart Association, 142 million Americans age 20 and older are overweight or obese. A high BMI then becomes a predictor for a multitude of health problems and diseases. Being overweight correlates with increased chance of diabetes, high blood pressure, heart disease and increase in the incidence and aggressiveness of malignancies, such as colon, pancreatic and prostate, says Cummings. Not only could you die sooner, the years of life you have when you are obese basically suck more. 

It takes only a few seconds to determine your BMI using the calculator on the website for the National Heart, Lung and Blood Institute’s Obesity Education Initiative, at www.nhlbisupport.com/bmi. But keep in mind that this standard calculator is for people age 20 and older—all the rapid hormonal changes that take place during puberty and make teenagers into crazy people, also necessitate a different way of calculating BMI. Overweight children and teens should talk to their doctors because the sooner they stop the real trend toward obesity, the better.

The best way to prevent excessive weight is to get started early with an active lifestyle, and maintain it throughout your life. I mean, seriously folks—looking good in a bikini is one thing, but do you want to spend the second half of your life hooked up to a respirator because of heart disease or have a foot amputated due to diabetes? Probably not. This is SoCal where the weather is always great so get outside more and find activities you enjoy, such as rollerblading, soccer, tennis, hiking, gardening, etc. Muscular strength is also important for maintaining a lean body mass, so lift weights or carry your groceries or do sit-ups while you watch The Biggest Loser.

The one caveat that I am almost hesitant to mention about BMI is that it doesn’t take into account the different substances that constitute weight. In other words, a short body builder may have 220 pounds of lean muscle mass, and thus a high BMI when they are clearly quite fit. But in American society, this is the exception rather than the rule. 

BMI is not actually a trend—it’s a tool to motivate change. Use it.