GREENVILLE, S.C. (WSPA)– Whether you’re trying to figure out the best dieting strategy or doing a simple health screening– you’ve likely heard the terms “BMI”, or body mass index.

As part of our “Ask the Expert” series, in partnership with Bon Secours St. Francis, 7NEWS spoke with a primary care physician about how to calculate this measurement and what it really means for your health.

Body mass index or BMI is a measure of body fat based on height and weight. It’s often used by healthcare providers.

Dr. Sanjana Iddyadinesh, a primary care physician, says the higher your BMI number, the more body fat you have.

She says, “As the BMI increases, then the chances of getting chronic conditions also climb. So, basically, like getting heart disease, cholesterol, or diabetes.”

Dr. Iddyadinesh says maintaining a healthy BMI is important for your health.

“18.5 to 24.9 is a healthy BMI,” said Dr. Iddyadinesh.

A BMI below 18.4 usually means someone is underweight or malnourished.

”So, from 25 to 29.5 is considered overweight. From 30 to 35 34.9 is considered first class one obesity, and then 35 to 39 is considered a class two obesity. So, it’s still obesity from 30 to 39, basically. Then, 40 and above is considered morbid obesity, so it’s class three obesity. They just divide obesity into multiple classes,” said Dr. Iddyadinesh.

To calculate your BMI, you should follow these steps:

Multiply your weight in pounds by 703. Divide that answer by your height in inches. Divide that answer by your height in inches again. (Check out the CDC’s “BMI Calculator” by clicking here.)

Dr. Iddyadinesh said if your calculations show a BMI number that is concerning to you, reach out to your healthcare provider because it might not always mean what you think.

She said “The measurement can be wrong. So, for example, if someone is very muscular then that muscle weighs more than fat, so that measurement can be, because it’s just weight with height. Their muscle weighs more so that does offer up offsets the BMI.”

Your doctor will use your BMI to create a plan of care for you.

“But, usually, if they fall in certain BMI’s and we do recommend some sort of health screenings like looking for fasting cholesterol lipids or glucose check or something like that, depending on where they stand with whether they are overweight or obese,” said Dr. Iddaydinesh.

If you are struggling with obesity, doctors will use your BMI To determine whether or not to recommend you for surgical weight loss.

“Someone above 40 usually qualifies for a bariatric weight loss surgery,” said Dr. Iddaydinesh.

Dr. Iddyadinesh said an annual physical is a great time to have your doctor check your BMI.

To submit a health topic for our ‘Ask the Expert’ series, click here.