What is Your Waist to Height Ratio?
There is little debate surrounding the relationship between excess bodyweight or obesity and non-infectious morbidities, but the means to assess risk factors is somewhat controversial. The previous standard of body mass index (BMI) has a great deal of grey area in it's interpretation. For example, I am 5'10 and 190 pounds. According to the BMI, I am considered overweight and at higher risk for cardiovascular disease, hypertension, diabetes, and numerous other chronic diseases. However, the BMI alone does not look at body fat percentage, distribution of body fat, or levels of aerobic fitness. In order to put the BMI into proper context, we must look at other factors.
Recently, there has been increased interest in the scientific community in determining what other measurements could help to put the BMI into proper context. The measurement with the most promise looks like it could be the waist to height ratio.
The waist to height ratio is a simple measurement of one's waist circumference compared to the individual's height. For example, my waist (at my belly button and hips) measures 32 inches and I am 70 inches tall giving me a waist to height ratio of .46. This can be easily computed with online calculators or a simple calculator on your phone. a waist to height ratio under 50% is generally thought to be a healthy measurement and lowers risk factors for many chronic and degenerative illness.
Why is that?
Waist to height ratio measures your distribution of body fat rather than simply looking at your weight. Storing more adipose tissue (fat) in your waist is associated with higher levels of inflammation, higher blood pressure, and is thought to interfere with organ function.
But has it been studied?
Yes, WHR has been studied numerous times. One of the more recent studies was a meta analysis which examined 2 epidemiologic studies out of Brazil. The link can be found here. This study looked at 13,729 participants and the association between waist to height ratio to chronic disease risk factors. The authors found that a WHR below 52-54% appeared to be associated with decreased risk factors of chronic illness, which agrees with studies that have been performed worldwide up to that point. This suggests that body weight alone may not be entirely predictive of risk factors related to illness, and that we should also look at the distribution of body weight.
Calculating your own waist to height ratio is simple. Take a flexible tape measure and measure the circumference of your waist across your belly button and at the top of your ilium. Divide that number by your height. Aim for less than 50%. Trying to decrease your waist circumference relative to your height is a fantastic fitness goal to strive for.