During your last doctor visit, we bet that he had you hop up on the scales. After weighing you, she probably showed you a colorful body mass index (BMI) chart with rows of boxes in shades of yellow, green, red, and orange.
If your BMI was in the green, then she might have informed you that you’re considered to be a healthy weight. However, the rough calculations that are used to place you in one of these boxes are just that – rough. They’re not actually a good measure of your health.
A growing body of evidence suggests that a better metric to determine whether you’re a healthy weight or not is the perimeter of your belly, also known as your waist circumference. Not only is measuring your stomach incredibly easy, that figure is also strongly linked to your risk of developing diseases such as diabetes, suffering from a heart attack, and dying early.
Why your BMI is not a good measure
The BMI was invented in the 1830s by a Belgian researcher who was aiming to create a simple way to size up the health of a large group of people based on two easy-to-attain measurements. It was never supposed to be used on individuals. When it is, problems usually arise.
This index doesn’t take into account your body fat or muscle composition, which means that it will give incorrect feedback based solely on things such as gender or lifestyle habits.
For example, if you’re an athlete, you’d be more likely to be put into the orange or red BMI box simply because you have more muscle than the average person.
Public-health experts have known about this for some time, and many suggest that belly measurements could be the solution.
Therefore, instead of estimating your BMI, pick up a tape measure. While breathing normally, wrap it around the part of your belly that’s about two inches above your hips. This is your waist circumference. In general, if you’re female, you want a measurement that’s less than 34.5 inches. If you’re a male, a number below 40 inches is ideal.
A measurement that’s higher than those figures isn’t a death sentence, but it has been strongly linked to a higher risk of several serious diseases such as type 2 diabetes.
Furthermore, a study published in March in the Journal of the American Heart Association suggests that a large waist circumference could also be linked to a higher risk of a heart attack.
As part of a larger 2012 study, researchers analyzed data from more than 340,000 people from eight different European countries. They found that overweight people with large waists – more than 34.5 inches for women and 40 inches for men – were at a similar risk of developing diabetes as those who are clinically obese. The link was strongest in female participants.
For the study published in March on the relationship between waist measurements and heart health, researchers used a large, ongoing health study to recruit nearly 500,000 adults with no immediate risk of heart disease.
The researchers then analyzed their waist circumference, BMI, and the ratio of their waist and hip measurements to determine if there was a connection between any of those metrics and a person’s chances of having a heart attack.
Their results suggested that those with higher waist measurements are much more likely to have a heart attack during the study period, which lasted 6-10 years depending on the participant. Just like the research on waist circumference and diabetes, the link was stronger in women than it was in men.
Scientists still don’t know why these ties between large waists and negative health outcomes are so strong. Some think that it has to do with how fat inside the body, known as visceral fat, may interfere with the normal function of our internal organs.