The most widely used and accepted body fat formula is the body mass index (BMI). This measure, however, is flawed and sometimes does not produce an accurate picture of overall health.
Some alternative body fat percentage formulas for measuring body fat composition and health have been proposed.
The body fat percentage (BF%) formula is a measure of the proportion of fat in the body.
A healthy body composition includes a high proportion of fat-free mass such as muscles, bones, and organs, and an acceptably low level of body fat.
What is the best body fat percentage for you?
There are a number of factors that can influence body fat percentage, including age, gender, diet, activity level, and genes.
According to the American Council on Exercise, men who are between 20-40 years old with over 25 percent body fat are considered “obese”, whereas a “healthy” range is described as between 8 and 19 percent.
For women in this same age group, any level over 39 percent is “obese” and 21 to 33 percent is considered “healthy”.
Body fat percentage provides important information on health status and fitness level.
Because of this, it is important to calculate your percentage of body fat and stay within the healthy range.
Calculate your body fat percentage
Weighing yourself on a bathroom scale does not give you enough information about your overall body composition.
Two common body composition measurements are BMI and skinfold estimates, neither of which are very accurate.
Measuring whole-body and regional distribution of fat and lean mass in a medical setting through dual-energy X-ray absorptiometry (DEXA) can be costly and technically challenging.
In a study published in the British Journal of Nutrition, a group of scientists from Israel developed distinct formulas for rapid and cost-free measurement of body fat percentage.
The equations to calculate the percentage of body fat – expressed as BF%cal – include measurements for height (H), abdominal circumference (A), and neck circumference (N), and are as follows (all in cm):
BF%cal (men) = 10.1 – 0.239H + 0.8A – 0.5N
BF%cal (women) = 19.2 – 0.239H + 0.8A – 0.5N
In their study, scientists analyzed 700 men and women between 20 and 60 years of age in a fitness club.
The participants were weighed, and their neck and abdominal circumferences were measured in the morning hours.
Any participants with chronic medical conditions were excluded from the study. The scientists validated their model with DEXA measurements.
BF%cal results are the most accurate body fat percentage formulas
The researchers proved the equations to be valid and can be applied to the calculation of body fat percentage in the general population of men and women.
In fact, 80% of the BF%cal results corresponded to the DEXA measurement.
The measurements that did not correlate with the DEXA measurement were equally distributed between being overestimates and underestimates.
This simple anthropometric measure offers rapid and reliable information on body fat conditions that require no sophisticated tools or professional training.
Reference: Lahav, Y., et al. 2018. A novel body circumferences-based estimation of percentage body fat. British Journal of Nutrition, 119(6), 720-725. DOI 10.1017/S0007114518000223.
