BMI (body mass index) has long been considered the yardstick for measuring a person’s health. However, new studies are beginning to show that it’s body fat percentage, not BMI, that indicates a person’s risk of developing insulin resistance, high blood pressure, heart disease, and even cancer. BMI is traditionally measured by dividing a person’s weight by their height and squaring it to determine if they’re within a healthy weight range.
Using a BMI chart to determine a person’s health can be dangerous as those with a low BMI might believe they are in good health. One study published in BMJ Open shows that people with a low BMI can be at greater risk of developing certain conditions because they think they’re healthier than they actually are.
A person’s percentage of body fat is not the only indicator of poor health; fat distribution also plays a big role. Specifically, fat around the midsection is considered to be one of the strongest indicators that a person will develop insulin resistance or type 2 diabetes. BMI doesn’t account for fat distribution, so the metric has a blind spot when it comes to assessing a person’s health.
For many people with a low BMI, health conditions like prediabetes can sneak up on them. A survey conducted by the Centers for Disease Control and Prevention (CDC) used a new scanning technology called dual-energy X-ray absorptiometry to get the most accurate measure of a person’s body fat percentage. In this survey, they found that 13.5 percent of people with a normal BMI had prediabetes or prediabetes. This proves that BMI is outdated and a dangerous measure of someone’s health.