Firstly lets define what makes up our body fat %.
The body fat % of a person is the total weight of fat divided by total weight: body fat includes essential body fat and stored body fat.
Essential body fat is required to help maintain our reproductive organs and more importantly keep us alive.
Before we dive in and look at what % body fat a certain person should be, we need to look at a few key variables.
Wagner and Heyward published a review article comparing body composition differences between black and white individuals.
They reported that black people have a greater bone density and body protein content that white people, which produces a higher density in FFM. (fat free mass)
Poehlman et al (4) measured body fat by using hydrodensitometry (underwater weighing) in 720 healthy white subjects (427 men and 293 women) and found a pattern of steadily increasing body fat with age.
However on the flip side there were also findings of lower fat mass and lower fat percentage after 60 yrs of age.
This is the most influential factor when it comes to body composition.
It is pretty fair to say that Men & Women are created differently, in more ways than one, but i’ll leave that conversation for another blog post.
Due to the demands of childbearing and other hormone functions, women have a higher essential body fat % than men.
Men have around 2-5% essential body fat whilst women have 10-13% (3)
Devices Used To Measure Body Fat Percentage
There are many ways in which you can test body fat %, and with each measure there will always be some variable in the final measurement.
You can use such measures as: skinfold callipers, underwater weighing, bio electrical impedance, ultra sound height and circumference methods & the one that many people seem to go off BMI.
With a well engineered weighing system, body density can be determined with great accuracy.
It begins with submerging a person in water and then calculating the volume of displaced water from the weight of the displaced water, corrections are made for body gases.
Dual Energy X Ray
X-rays of two different energies are used to scan the body, one of which is absorbed more strongly by fat than the other. A computer can subtract one image from the other, and the difference indicates the amount of fat relative to other tissues at each point.
A sum over the entire image enables calculation of the overall body composition.
The only draw back on this method, along with the Underwater weighing, is that they are very expensive methods.
Bioelectrical Impedance Analysis
Unlike the above methods the BIA is a lower cost option, however can still range in the hundreds of dollars to get a test.
The BIA works by attaching 2 or more conductors to a persons body then sending a small current through the entire body (dont worry it is not like touching an electric fence).
The resistance between the conductors will then provide a measure of body fat.
Factors such as eating, drinking and exercising must be controlled prior to a test since hydration levels are an important source of error in determining the electrical flow to estimate body fat.
When it comes to measuring body fat % the BMI went out with the tide, however it is still a largely used method to determine ones body fat.
Most Doctors still use this as a measure. Personally i believe they should dust off the book shelf and start learning, newer more accurate measures.
The BMI is a measurement of weight in kg’s divided by height in metres.
The problem with this method is that is does not take into account the muscle mass of the individual. i.e.: i am 95kg male and sit around 10-15% body fat (measured by 9 site skinfold test) however according to the BMI test i am in the high healthy risk range
WHAT! I am fitter & feeling healthier than I have ever been, how can this be?
ill tell you why, its because the BMI measurement method is not for everyone.
What i mean here is, the average person is not of muscular build like myself, i have been training for years to build this physique, however if i was unaware of how this body fat % worked, i would go to the doctors and he would tell me I am in a high healthy risk range.
This is the method in which we personally use to determine a body fat % estimate.
I call it an estimate as there is always going to be error.
Skin folds are taken from specific sites around your body. Personally we use a 9 site methodology.
Some skin fold test only require 3 sites to be taken, however you can already start to see the error with that right?
9 sites is going to provide a far more accurate result than only taking 3.
I also like skin folds as you can get a specific measure of where you are holding the most body fat, ie: you can take a skin fold measurement from your Umbilicus (stomach area) and then in a couple of weeks time you can re check to see your loss.
Body Fat Percentage Categories
(the below image is for example purposes only)
(from the American Council on Exercise)
In my professional opinion, it is extremely hard to classify 7 billion people into 5 categories, however the table above will give you a very good idea on where your body fat percentage should be.
When it comes to skin fold testing, be sure to ask the practitioner how many examinations have they done due to the degree of inconstancy with these tests.
It takes hundreds of tests to be able to get it right and as accurate as possible.
Also be sure to be retested by the person who did the original test, each examiner can have there own way that can also differ slightly.
How To Know If You Need To Lose Some Body Fat
This is an extremely easy, cost effective way to determine if you should lose some body fat.
If you can grab a good chunk of body fat from your stomach, tricep or thighs, it will be pretty safe to say you would have a few kilos of Body Fat (not necessarily weight) to lose.
Remember this as a rule of thumb.
You do not want weight loss, you want FAT LOSS. And to achieve fat loss, you may sometime go through weight gain, but remember the weigh gain, if you are training and eating properly will be muscle gain,
and muscle gain is good, lean muscle gain that is, because the more muscle your body has, the more fat you can actually burn by doing nothing.
So i will leave you with this:
For the skim readers:
Your body needs fat to survive
Muscle Burns Fat
BMI is a very inaccurate way to determine body fat percentage
There are many ways to measure body fat, for the most cost effective way and with a high degree of accuracy I would recommend a skilled skin fold practitioner, ensure they use 9 sites as this will provide a more accurate result.
- ACE (2009) American Council on Exercise (ACE). Ask the Expert Blog. December 2, 2009.
- International Journal of Obesity (2002) 26, 789-796. doi:10.1038/sj.ijo.0802006
- Fahey, Thomas; Insel, Paul; Roth, Walton (2010). “Body Composition”. Fit & Well: Core Concepts and Labs in Physical Fitness and Wellness. McGraw-Hill. ISBN 978-0-07-352379-8
- Poehlman ET, Toth MJ, Bunyard LB, et al. Physiological predictors of increasing total and central adiposity in aging men and women. Arch Intern Med 1995;155:2443–8.
If you are wanting to lose a few extra kilos of unwanted body fat, then check out some of our awesome online workout systems that you can do in the privacy of your own home.
if you liked this article you may also like these links.
Please Leave a comment below on what you thought of this article.