You hear a lot of talk about body fat percentage in the fitness world. So what is it? How much is a good body fat percentage? How do I measure it? Here I answer all of these questions.
Basically body fat percentage is just a measure of how much fat is in your body, compared with your total body weight (which is made up of your bones, muscles, tendons, organs, water, etc).
Women and men have different healthy body fat percentages. Women typically store more body fat, because it is in our genetics – hormones, boobs, plus we need a higher body fat for ovulation and child bearing. Lucky us…
What you consider an ideal body fat percentage, really depends on your personal preference. Here is a chart from the American Council on Exercise, which is one of the most commonly used body fat charts.
Everyone needs body fat. “Essential fat” is the amount of fat required for survival. Anything less than this amount would likely result in organ failure.
As you can see, women and men have different body fat requirements. A woman with a body fat percentage of 25% would like very different to a male at 25% body fat.
For us females, if you’re looking for the lean and toned look, you would be aiming for somewhere in the athletes range. However, everyone is different. So your body may look lean and toned at say 21% (good for you!). If you just want to look healthy, then aim for somewhere in the fitness range. If you are within the obese and higher end of average ranges, then I would suggest trying to reduce your body fat percentage.
Personally the last time I had my body fat percentage measured I was around 19% (using Inbody – read more below). This tends to be the body fat amount that my body is able to maintain easily. To reduce body any lower than this, I need to really focus on my diet and exercise.
There are a few different ways of measuring your body fat. I will start with the most accurate, to the least accurate.
A DEXA scan is the most accurate method to measure body fat. It is only done at certain health facilities and you lie still on a table for a few minutes while an x-ray machine moves over the top of you. It can be pretty costly (anywhere from $60-$200).
Inbody machines require you to step onto the machine and hold onto little pads for your thumbs. It uses electrical currents to measure resistance values of your arms, legs and trunk. The Inbody machine is about 98% correlated with the DEXA so is highly accurate. It is much less expensive (anywhere from $20-$50) and can be found in higher end gyms.
I should mention that there are lots of other machines similar to this that you step on to measure body fat. They are inaccurate. Most of them underestimate your body fat percentage significantly.
This method calculates your body fat percentage using air displacement to measure body mass, volume and density. It is very accurate but can also be pretty expensive. I haven’t had this done and haven’t done too much research on it.
Most personal trainers are trained in this method. It is quite accurate, but often underestimates your body fat percentage by around 2-5%. I had my body fat measured with the calipers and came up around 15%, but was actually 19%. It is not too expensive, and can be useful for comparison. Just make sure you get it done by the same person.
These are highly inaccurate and often significantly underestimate your body fat percentage. It is also affected by how much water you have had to drink and how much is stored in your body. However, it can be useful for comparison, but just won’t give you an accurate measure of your body fat. Also, make sure you use it at the same time (i.e. first thing upon waking before you had have any water) and before you exercise.
BMI only takes into your weight and height, and their ratio. It is not directly correlated to your body fat percentage. So a female who is 163cm tall, weighs 70kg, with a body fat percentage of 15% would be considered overweight. It doesn’t take into consideration your muscles or the size of your bones.
I’ve done a post on this already (read my how to reduce body fat post here), but here is some quick advice.
Generally to lose weight, you need to be eating at a calorie deficit (i.e. eating less calories than you eat). You may lose some muscle mass, but to lose body fat you need to be in a calorie deficit.
Having muscle will help you reduce your body fat, by helping increase your metabolism (meaning you will burn more calories). Make sure your program is includes some weights, even if it just HIIT or light weights.
Cardio also helps because it burns a lot of calories! If you can do cardio in a fasted state (i.e. before breakfast), it will also help as your body will turn to fat stores for energy.
Carbs are your body’s preferred source of energy. When you eat low carb, your body now has to turn to fat stores for energy. This is why you will see body builders dramatically reduce carbs before a show. Extremely low carb is not sustainable long term. So after a period of low carb, make sure you increase your carbs slowly. If you do it too quick, you might gain fat.