What is BMI?

Do you ever leave the doctor’s office with more questions than answers? Or maybe you are familiar with a term or measurement the doctor used but need a refresher on what exactly it means or why it is important. Over my next few articles, I will discuss common assessments and terms that might come up at your next checkup. In addition to the focus of this article, Body Mass Index or BMI, look for articles exploring waist circumference, cholesterol types and levels, and blood sugar. 

Doctors and health care professionals use a variety of tools to make health evaluations; BMI is a common assessment tool you may have heard during your last visit. Developed in the mid-1800s, BMI is a simple way of assessing the general health of a person with an average fitness level. BMI was originally developed to evaluate overall populations, rather than an individual assessment, but due to ease of use, it has become a popular tool for health care providers. 

To calculate your BMI, divide your weight by your height squared, then multiply that result by 703. BMI is helpful to doctors because it categorizes patients into four categories (in the US): Underweight = <18.5, Normal weight = 18.5-24.9, Overweight = 25-29.9, and Obese = >30.  For example, if you weight 160 lbs. and you are 5’5” tall, to calculate your BMI you need to divide 160 (your weight in lbs.) by 4225 (height in inches squared or 65x65) and then multiply that by 703; (160/4225) x 703 = 26.6. Your BMI is 26.6 and this classifies you in the overweight category.

BMI is widely used as an overall measure of general health; however, it may provide a slightly skewed assessment for some. Due to the density of muscle vs. fat, an athlete or someone with a high muscle to fat ratio will have a higher BMI than someone of a similar shape and size with less muscle mass. If your calculation lands you in an undesirable category, you may need to address one or more aspects of your diet and/or activity level. Your healthcare provider will be happy to discuss your BMI and any associated actions needed.

In general, BMI is a useful tool. Even if you are not in the normal weight range, you can use the number to compare where you are to where you should be for health purposes. It is always important to remember that people come in all shapes and sizes and one assessment can only give a general idea of health. If you have questions regarding your BMI, talk to your health care provider. Before beginning any exercise, program or changing your physical activity patterns, you should always consult your health care provider. 

If you have questions or concerns, please contact me, (903) 473-4580 or email Sarah.Latham@ag.tamu.edu. To view upcoming events or additional information please visit https://rains.agrilife.org/ or follow Rains County AgriLife on Facebook.