Scientists at the Keck School of Medicine at the University of Southern California, in the United States, have developed a new way ofmeasure whether a person is overweight without using a scale. It is calledBody Fat Index (IAC), and is based on height and hip size. Specifically, the measurement is obtained by dividing the hip circumference by the weight raised to the 1.5 power. The result obtained must be subtracted 18.
The new measurement is much more precise than the “classic”Body Mass Index (BMI), used during the last two centuries, and which is calculated by dividing the weight in kilograms by the height in meters. According to study author Richard Bergerman, BMI is not a perfect measure. For example, men with a BMI of 30 may have a fat level of 25%, while in women the fat percentage is more likely to be 35%. In addition, there are people with a body index greater than 25 (theoretically, “overweight”) who have a lot of muscle mass and no fat. With BMI, you get a “relative number,” Bergerman says. The IAC, by contrast, “measures the percentage of fat.”
Bergerman and his team obtained the new index by studying 1,733 Mexican-American and 223 African-American subjects. And they confirmed the precision of the scale using a device called a dual-energy X-ray absorption scanner that allows determining the percentage of fat, as reported in the latest issue of the magazine.Obesity. The next step, they announce, will be to test it with other ethnic groups to “fine-tune” the scale.
