Yellow Fat Person - © Unknown

Obesity File: New Fat Metric More Accurate Than BMI?

Researchers in Finland have discovered that a new, simple measurement can better define obesity than the prevailing formula, Body Mass Index (BMI). And it’s a better predictor of your chance of dying prematurely from obesity-related causes…

Dr. and Fattie - ©

What they did

A team from the University of Eastern Finland (UEF) wanted to see if a proposed new ‘yardstick’ for obesity was more or less accurate than the lone-employed BMI standard.

The new measure is simply the ratio of waist circumference to height.

“The Dual-Energy Xray Absorptiometry (DEXA) scan accurately measures fat and muscle content of the body, but this device is not readily available in primary health care centres,” an abstract of the study report explains. “Recently, the American Academy of Pediatrics (AAP) published a clinical guideline on childhood obesity and requested urgent research on inexpensive and accurate alternative measures of obesity.”

Researchers compared BMI measurements and Weight-to-Height measurements to DEXA scan results for muscle and fat mass. Their subject pool was drawn from the University of Bristol’s Children of the 90s study data. That program followed 7,237 children (51 percent female, 49 percent male) aged 9 years who were followed-up until age 24. Height and waist measurements were recorded at regular intervals.

What they found

In a nutshell, the UEF study discovered that the Weight-to-Height ratio measured obesity more accurately than BMI.

“Waist circumference-to-height ratio had a very high agreement of 81 – 89 percent, with DEXA-measured total body fat mass and trunk fat mass, but a low agreement with muscle mass (24 – 39 percent). BMI had a moderate agreement with total fat mass and trunk fat mass (65 – 72 percent) and muscle mass (52 – 58 percent).”

The takeaway

It appears the AAP’s wish has been fulfilled. And the Waist-to-Height ratio is much easier to use. Even the math-challenged – such as yours truly – can work it out.

For your reference, a ratio of 0:53 for men and 0:54 for women is the ‘cut point’ indicating ‘excess weight’. In other words, if your waist measurement is more than half your height, you’re fat. And the lower the height number, the fatter you are.

My take

The W-t-H ratio is something I can readily relate to. I always thought BMI was a little too clinical (not to mention mathematically challenging) to suit my needs.

And I’m also happy to say, the new ratio places my own obesity index comfortably within the ‘safe’ range. But I still have a long way to go until I get back to my self-defined ‘ideal weight’. Yes, I’m preparing for a diet-and-exercise assault on my extra pounds.

I’ve already started on the diet side. I’ve cut out alcohol completely, added green, leafy veggies to my daily routine, and reduced my starches. I’m eating ‘clean’ proteins and upping my intake of whole grains. When the weather gets a little milder, and I can ditch the snow boots in favour of sneakers, I’ll start walking again, every day, for at least 2 km. To start. And I’ll keep you posted on my progress…

~ Maggie J.