Beyond BMI: A Better Tool to Measure Your Health

Tape measure

If you’ve been to a doctor, looked at medical websites or watched a daytime talk show, you’ve probably heard the three magic letters BMI.

BMI, or body mass index, is the most basic tool doctors use to check your body composition and predict your risk of disease. There are plenty of online BMI calculators that will do the math for you, but it turns out there is a better tool at your disposal: waist-to-height ratio. Best of all, just like BMI, you can measure it yourself.

DIY disease predictor

All you need to measure BMI is your height and weight — plus a calculator or good head for math. All you need to measure your waist-to-height ratio is your waist size and height. A tape measure will do the trick.

“All you need to measure your waist-to-height ratio is your waist size and height. A tape measure will do the trick.”

Karen Cooper, DO

Women’s Health Institute

But waist-to-height ratio isn’t just simpler; it’s also better. Researcher Margaret Ashwell made the case for this measurement last year after studying the health of 300,000 patients. She found that waist-to-height ratio is better than BMI at predicting diabetes, hypertension, heart attacks and strokes.

BMI doesn’t take into account lean body mass versus body fat, so a very muscular person could end up classified as overweight and at-risk. Waist-to-height ratio does a better job of avoiding that problem by including the waist, where abdominal fat lives. Abdominal fat seems to be the worst kind when it comes to disease risk.

How to measure

To be healthy, your waist circumference should be less than half of your height. For example, if you are a 5-foot (60 inches) female, your waist circumference should be 30 inches or smaller. Keeping that ideal ratio will reduce your risk of disease — and increase your life expectancy.

To get an accurate waist measurement, don’t just measure where your pants sit — and avoid the urge to suck in your gut like you’re in a photo. Instead, relax, and start the tape measure just above one of your hip bones and below your lowest rib, keep it level at the belly button all the way around. You want the tape measure to be snug, but not compressing your body.

If the measurement is more than half of your height, use that as motivation. You can make smart choices, lose that harmful abdominal fat and give yourself a longer, healthier life in the process.

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Karen Cooper, DO

Karen Cooper, DO, Director of Be Well Moms℠ in the Women's Health Institute, is board-certified in family medicine and specializes in medical weight management.