Waist-to-Height Ratio vs. BMI: Which Is the Better Indicator of Health Risks

For years, Americans have been relying on BMI (body mass index) as an indicator of obesity and the health risks associated with obesity, like heart disease and diabetes. However, according to Dr. Margaret Ashwell of the UK, a consultant in nutrition science, specializing in obesity, BMI is not the most accurate way to determine whether or not a person is overweight and at risk for these diseases. Instead, Ashwell suggests using your waist-to-height ratio to determine your risk.

What Does BMI Measure?

Your BMI is a measurement based on a combination of your height and weight. Predetermined ranges of BMIs are used to determine how healthy a person’s weight is. According to the National Heart, Lung, and Blood Institute, the BMI chart is as follows:

  • Underweight = <18.5
  • Normal weight = 18.5–24.9
  • Overweight = 25–29.9
  • Obesity = BMI of 30 or greater

However, the problem with this method is that it does not take into account fat distribution throughout the body. For example, Arnold Schwarzenegger and Danny DeVito both have BMIs of 34, despite their vastly different builds. In Schwarzenegger’s case, muscle weight hikes up his BMI, even though he has little body fat. On the other hand, DeVito’s short stature could downplay his risk of health problems related to obesity.

How to Measure Your Waist-to-Height Ratio

Instead of relying on BMI as the sole indicator of a person’s risk of obesity and associated health risks, Ashwell asserts the importance of knowing your waist-to-height ratio.

To take this measurement, simply measure how tall you are using a piece of string or flexible measuring tape. Then, fold it in half and place it around your waist. Ideally, your waist will be less than or equal to half of your height. So if the two ends of the string meet or overlap, you are considered a healthy weight.

If the string does not fit around your waist, losing just 5% of your body fat could have a significant impact on not only your weight but also potential health risks like heart disease and diabetes. Remember that the goal is to get rid of the visceral fat that surrounds your organs, not to crash diet to drop the number on the scale.