Body Adiposity Index: A New Way to Measure Whether You’re Overweight or Obese?

February 26, 2012

by Cathe Friedrich

BMI or body mass index has been the standard for measuring whether a person is overweight or obese for almost 160 years. To calculate BMI, you simply plug your height and weight into a BMI calculator and out pops a number. You can also calculate your BMI quickly and easily in our free online Workout Manager. The calculated BMI compared to a standardized BMI chart to determine whether you fall outside the normal range.

The problem is BMI has its flaws and limitations. It doesn’t take into consideration how much of your mass is muscle and how much is body fat. A person who’s very muscular can fall into the overweight category even if they have little body fat. That hulky guy at the gym who bench presses twice his body weight could be classified as too heavy based on this formula.

Now a new way to measure whether a person is carrying around too much fat is being proposed. It’s called the body adiposity index. Unlike the BMI, the body adiposity index doesn’t take into account a person’s weight. It involves measuring height in meters and hip circumference in centimeters. The formula is rather complex, but there are calculators online that can do the calculation quickly.

Researchers at the University of Southern California who have been working with this formula believe a person’s body adiposity index or BAI is a better indicator of excess body fat than BMI. Ideally, doctors would be able to measure a person’s body fat percentage to determine whether they’re overweight, but the most accurate measurement of body fat is a DEXA scan, which is expensive and isn’t always practical. They discovered that a person’s hip circumference compared to their height is a good measure of body fat percentage and compared favorably to body fat percentage measured by a DEXA scan. It’s a fast method for determining whether or not a person is overweight or obese without using expensive testing.

It’s unlikely that the BAI will replace BMI anytime soon. Researchers have only validated it in Mexican-Americans and African-Americans. It still needs testing in other ethnic groups. They have already found some discrepancies between values in very thin Mexican-Americans and African-Americans. It’s also not a good tool for assessing abdominal obesity since it focuses on hip measurements. Abdominal obesity carries greater health risks than fat carried around the hips.

You can already find BAI calculators online, but don’t place too much stock in the results just yet. Researchers admit that it needs to be further tested and fine-tuned before it replaces BMI. An alternative way to measure body fat is to use a body fat scale. These scales use a mild electrical current passed through the feet to estimate body fat percentage. You can buy these scales online, and although they’re not as accurate as a DEXA scan, they give a rough estimate of body fat percentage. They can also be used to follow changes in body fat composition over time. It’s probably the best alternative for measuring your body fat percentage at home.