Body Mass Index: What Is It, and Why Is It Important?

News and Advice, Weight Loss
on June 7, 2011

Whether you want to lose weight or maintain your current healthy weight, knowing your body mass index (BMI) is very important because this number can be used to determine whether your weight puts you at risk for health problems. It’s one thing to strive to fit back into your skinny jeans, but in our appearance-obsessed culture, we often forget about the bigger picture. Maintaining a healthy weight can help you prevent any number of health problems (such as diabetes and heart disease) and the subsequent cost of treating these medical issues. You can use your BMI as a tool to help keep you in a healthy, low-risk weight range.

Calculate your BMI. Many major health websites offer tables that help you quickly calculate your body max index. For example, we found a good one on the Weight-control Information Network (WIN), an information service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). However, you can also calculate your BMI using a simple mathematical equation:

(Weight in pounds x 703) / (Height in inches) squared = BMI

For example, if you are 5 feet tall and weigh 150 pounds, your BMI would be 29.29. Note that to calculate your BMI, you need to multiply your weight by 703, divide the answer by your height in inches, and then divide the answer by your height once again.

Know what your BMI means. Calculating your BMI is pretty simple, but this number does you little good if you don’t know what it means. According to the WIN website, a healthy BMI is between 18.5 and 24.9, whereas an individual with a BMI of 25 to 29.9 is considered overweight. Therefore, the 5-foot, 150-pound individual we discussed above would be considered at the high end of the overweight range. Someone with a body mass index of 30 or higher is considered obese and is at risk for developing medical issues related to obesity, like high blood pressure, diabetes and coronary artery disease. The Cleveland Clinic adds another category in its BMI assessment, classifying someone with a BMI of more than 40 as morbidly obese (at risk for death due to obesity-related issues).

As you can see, your body mass index is no arbitrary number; rather, it says something about your risk of developing very serious and highly preventable obesity-related health conditions. If you’re trying to lose weight, the number on the scale can be a great motivator and progress-tracker. Just make sure that your goal weight correlates with a healthy BMI, and you’ll have one more reason to stay on track with your weight-loss goals.