Understanding Body Fat Pt. 2
Healthy body fat ranges and distribution patterns:
One of the most common questions that are asked is “how much body fat should I have?” Though total fat mass is important, we must also consider where the fat mass is distributed to calculate potential health risks.
Guidelines have been set for circumference of the waist in relation to central adiposity concerns. For males they have been set at 40 inches (102cm) and over and for females at 35 inches (89cm) and over.
There are many different ideas and classifications as to what is a “healthy” bodyfat percentage for males and females. We know that we require an essential fat level, where by if we drop under this level physical health would be negatively affected. These levels of essential fat have been determined to be between 2-5% for males and 10-13% for females.
Once you go over the essential fat levels, opinions on “healthy” bodyfat levels varies greatly.
How do we measure bodyfat?
There are many ways we can measure bodyfat, with some ways being more accurate than others. Below is a list of the most popular methods and some of their positive and negative charactersistics:
Hydrostatic Weighing – Subject is submerged in water to calculate body density
Positive – Gives an actual measurement of body density rather than a prediction
Negative – Requires specialized equipment and difficult to remove all residual air from lungs
DEXA Scan – X-rays of two different energies are used to scan the body
Positive – Currently the most accurate way to measure bodyfat
Negative – Requires highly specialized and very expensive equipment
Bioelectrical Impedance Analysis – Small electrical current is sent through the body and the different resistance between muscle, fat, etc is measured
Positive – Relatively cheap equipment and simple test to carry out
Negative – Inaccurate and result is effected by hydration levels
Skinfold Callipers – Subcutaneous fat levels are measured with callipers at standardized points on the body
Positive – Very cheap equipment and simple test to carry out
Negative – Potentially high degree of human error and only measures subcutaneous body fat
The type of bodyfat measurement you are most likely to come across is the skin fold callipers. This is a simple test that involves equipment that is easy to use and the test can be done in minutes. There are several formulas that have been developed to estimate total subcutaneous bodyfat levels based off three, five, seven and twelve skinfold site tests.
In the hands of a skilled and experienced practitioner the calliper test can be quite effective in giving an approximate amount of subcutaneous body fat. It has been estimated that a suitable level of proficiency in the calliper test is reached after the practitioner has performed approximately 5,000 tests, so the possibility of human error must be expected when performing this method of testing.
Bioelectrical Impedance Analysis machines are often sold as quick and easy ways to give you and accurate reading on your bodyfat percentage, but unfortunately this is not the case. There are many variables that affect the reading of these machines. These include:
• Hydration Levels: If you are slightly dehydrated it will score your bodyfat percentage higher. You can affect your score simply by drinking a litre of water and doing the test again.
• Site Sensitivity: The BIA machine is most sensitive to where you make contact with it. If you stand on the sensors it will likely show you have a higher distribution of bodyfat in your lower body and vice versa for hand held sensors.
• Manufacturer: There is also a huge difference in results between manufacturers. You could step on one BIA and record a score and then step onto another BIA from a different manufacturer and see a completely different score.
Though the idea of a quick and easy assessment of bodyfat percentage and distribution with a Bioelectrical Impedance Analysis machine may sound appealing the reality is a result that is anything but reliable or consistant.
As a KX gym supervisor, strength & conditioning personal trainer and functional medicine consultant, Aaron co-runs the KX Fitness Department and the unique KX Functional Assessments. Aaron is further responsible the continued education of the full team of KX Fitness Advisors and currently features monthly in Men’s Fitness as one of their “Resident Experts”.
• Gym Supervisor KX Functional Assessment Team.
• Strength & Conditional Personal Trainer
• Functional Medicine Consultant
• ISSN certified Sports Nutritionist
• Runs KX Internship Educational Qualification