Novel flexible way to measure percentage body fat

11-Mar-2011 - Last updated on 11-Mar-2011 at 15:52 GMT

Related tags Body mass index Obesity

A new way to measure percent body fat offers a more flexible alternative to body mass index (BMI), according to the scientists from the University of Southern California, Los Angeles who developed it.

The new technique, the Body Adiposity Index (BAI), involves measuring hip circumference and height to accurately determine percent adiposity.

Writing about the method in American journal Obesity, lead researcher, Richard Bergerman and colleagues stated: "After further validation, this measure can be proposed as a useful measure of per cent fat, which is very easy to obtain. However, it remains to be seen if the BAI is a more useful predictor of health outcome, in both males and females, than other indexes of body adiposity, including the BMI itself."

BMI, the current technique which relies on measuring a ratio of height and weight, is used widely by researchers and doctors

Body mass

“Although body mass index has been used as a measure of body fat since the 19th century, it does not reflect true adiposity and cannot be generalized across genders or ethnic groups,” wrote the researchers. Men and women with the same BMI might have different levels of flab.

Also BMI cannot be used to assess athletes, who have extra lean body mass.

The new measure could be particularly useful in areas of the world where body weight cannot be reliably measured. Armed with just a calculator or computer, health care professionals can calculate BAI measures.

BMI is calculated as weight in kilograms divided by height in metres squared, rounded to one decimal place.

The scientists developed the index using data a Mexican-American population study known and BetaGene and validated it using the TARA study of African Americans.

Meanwhile, obesity-related diseases account for nearly 10 percent of US medical spending, or an estimated $147bn a year.

A recent Statistics Canada survey revealed that 34.4 percent of Americans and 24.1 per cent of Canadian adults were obese between 2007 and 2009.

American men

Just over 36.2 percent of American women were classed as obese compared with 23.9 percent of Canadian women. Of the American men surveyed, 32.6 percent were obese while 24.3 percent of Canadian males fell in the same category.

The statistics were drawn from the results of the Canadian Health Measures Survey and the National Health and Nutrition Examination Survey.

Worldwide obesity is thought to affect more than half a billion people, or one in 10 adults – twice the number recorded in 1980.

Obesity is a risk factor for many diseases, including type 2 diabetes mellitus, cardiovascular disease, hypertension, and cancer.