© Tobyotter (Flickr) A Matched Set
© Tobyotter (Flickr)
Different types of body fat.
Sex and culture
Understanding the right place on the fat scale for each individual is not as straightforward as first thought. Not only is there a big difference in ideal percentages for men and women, children and adults, and sports and sedentary people, there are also significant cultural differences to consider when ascertaining your ‘correct’ body fat percentage.
In humans, fat is located beneath the skin (in the subcutaneous level), around the organs, in bone marrow and in breast tissue. This is adipose fat, it protects organs, provides insulation against the cold and acts to reserve lipids which are, in turn, burnt to generate energy.
The body has a need for essential fat, the level below which physical health will decline. Very fit athletes may have fat levels of 6% for men and 14% for women. For non-athletes, even those on a fitness diet or normal diet, a female would be expected to have 20% to 35% bodyfat, and a man 8% to 25%, dependent upon age.
Body fat meters, usually skin calipers, are sometimes used to measure levels of waist fat. However, calculations from this technique often under-read body fat percentage.
Body Mass Index
One indicator of overall fitness, and a healthy weight, is the Body Mass Index or BMI calculation. This is calculated using the following formula:
bodyweight in Kilos / height in metres squared
A non-metric equivalent is:
bodyweight in pounds x 703 / height in inches squared
To understand how you measure-up against a normal BMI measurement, use the following table.
BMI less than 18.5: underweight
BMI 18.5 to 25: normal
BMI 25 to 30: overweight
BMI over 30: obese
The best calculation method
The fat formula
Once you have established your BMI, it is possible to calculate a reasonably accurate body fat percentage. Use the following formula, replacing the word ‘gender’ with 1 for males and 0 for females.
Child body fat % = (1.51 x BMI) – (0.70 x Age) – (3.6 x gender) + 1.4 Adult body fat % = (1.20 x BMI) + (0.23 x Age) – (10.8 x gender) – 5.4