Move Over BMI: Doctors Say There's A Better Way To Gauge Whether You're Overweight

NEW YORK (CBSNewYork) – Doctors say being overweight or obese carries big health risks, including heart disease and cancer.

Your body mass index, or BMI, has long been the way doctors tell whether you're overweight. But as CBS2's Dr. Max Gomez reports, there's now a better way to gauge your health risk from too much weight.

BMI is a kind of crude measure for overweight. It's just how much you weigh vs. your height.

But where you carry any extra weight turns out to be a better way to assess how much of a health risk those extra pounds might be causing.

"For BMI purposes, I fall right in the normal range. My weight has been normal for the past 25 years," Susan Reed said.

Not only that, she bikes and kayaks and her diet is mostly vegetarian. So imagine her surprise when her doctor told her she had a fat problem.

"Your weight in pounds does not necessarily reflect how much fat you have, nor does it reflect where the fat is located, which is really the risk factor that we're interested in," said Dr. Steven Goldstein, with NYU Langone Medical Center.

Doctors now realize that not all fat is created equal, at least not when it comes to your health.

"Fat in your hips, fat in your legs – that's usually storage fat, not metabolically active. But fat in your belly causes inflammation in the rest of you, especially in those organs," said Dr. Michael Roizen, of the Cleveland Clinic.

A recent study found that the number of people with excess abdominal fat is actually much higher than the number of people deemed obese and overweight by BMI measurement. And that excessive abdominal fat is what leads to a heightened risk of chronic disease, reduced quality of life and increased risk of death – regardless of a person's BMI.

There's a simple way to tell if you have excess abdominal fat, and therefore are at elevated health risk.

"The best measuring device is actually a tape measure. Put it at your belly button, put it around yourself, suck in – you will anyway – and that number should be half or less of your height," Roizen said.

Men tend to store their extra weight in their bellies – what's sometimes called a pot belly or a beer gut. That apple shape is more dangerous than where women tend to store fat around their hips and bottoms – the so-called saddle bags that are known as a pear shape.