Every fitness magazine, every Sunday newspaper supplement is bombarding us with ‘get fit quick’ programmes or promising us ‘beach bodies’ that take little effort. Most of these articles hinge around attaining a low body fat percentage.

What is body fat percentage?

Body fat percentage (BF%) tells us what proportion of you is body fat and what proportion of you is fat-free or non-fat. Non-fat mass consists of your bones, muscles, organs, ligaments, etc. So, when we talk about your body fat percentage we are referring to how much of your body composition is solely fat.

So, a low body fat percentage, as advocated by the beach-body articles, means getting to a point where a smaller, rather than a larger, proportion of your body composition is body fat, and a bigger proportion of you is muscle. Fat and muscle are the only components of your body composition that you have any control over; bones, organs, skin and other fat-free tissue you’re stuck with.

The problem with body fat percentage

Now, whilst body fat percentage (BF%) is an easy number that everyone can identify with, it is not, actually, the best number for determining your level of fatness. Most people use BF% as an absolute measure of body fat. IT IS NOT! It is the proportion of you that is fat. You can have a lower body fat percentage than someone else but carry a higher quantity of body fat and hence be “less healthy” that they are.

If you watch the clip below (it will start with the words “These two men…”), you’ll understand why BF% (a single number, just like weight and body mass index) has some very big drawbacks.

Different ways to calculate body fat percentage

Despite the drawbacks of BF%, we’ll press on and look at ways to determine either the metric itself or your overall level of fatness.

Without using an specialist equipment, looking in the mirror and taking your waist measurement are the simplest methods. Indeed, in 2022, NICE (the National Institute for Health and Care Excellence, issued guidance that says a waist measurement of more than half of a person’s height is an indication of increased fat in the abdomen and is associated with a greater risk of developing conditions such as type 2 diabetes or cardiovascular disease.

Whilst a tape measure and mirror will tell you if you are “officially” overweight (over-fat), it won’t give you your BF%, which needs more data. Here are four methods and pieces of equipment for calculating your body fat percentage:

Bio-imdedance Analysis (BIA) devices

Whether worn on the wrist or stood on in the bathroom or at the gym, BIA devices send a small electrical current through some or all of your body and come up with a number for your BF%. Whilst popular (because they are cheap and easy to use), they are extremely inconsistent. A huge number of Bodyscan customers say they have some BIA scales but are driven to distraction by their day-to-day volatility, which delivers wildly different results for their body fat percentage.

Skinfold (pinch) calipers

If you have a personal trainer, they might try and impress you with these specialist medical-looking devices. Your PT will use the small, spring-loaded vice to pinch your skin and the subcutaneous fat beneath it at different pinch-points over your body (which can be quite uncomfortable in sensitive areas). The number of pinch-points may range from four or five to 12, 15 or more. The PT will then plug their measurements into a formula and try and arrive at a figure for body fat percentage. Most people are not qualified to use calipers, so they are best at just establishing a trend – if you can pinch more you’re putting on fat, if you can pinch less you’re losing fat. And you can do that easily enough with your own thumb and finger!

Underwater (hydrostatic) weighing and BodPod (air displacement plethysmography)

You’ll probably need to find a sports science lab to find an underwater weighing facility (which used to be regarded as the gold standard for ody composition analysis). BodPod uses the same principle but based on the displacement of air, rather than water. In Bodyscan’s anecdotal experience, customers who have used BodPod have had body fat percentage results which differ significantly (higher and lower) to those provided by DEXA. Also, in recent years far fewer customers seem to have tried BodPod, probably because the cost is close to that of DEXA while being much less reliable and, for both the air and water versions, you have to wear your swimsuit.

DEXA (dual-energy X-ray absorptiometry)

Any scientific research worth its salt will use DEXA as the measurement tool. It’s a big, expensive, medical-grade piece of technology which is extremely consistent when it comes to measuring body fat. The UK’s best sports science universities have their own DEXA scanners, though their inherently small research projects mean that Bodyscan has performed, far and away, more DEXA body scans than anyone else in the UK (and probably Europe). The depth and breadth of DEXA metrics mean that Bodyscan can provide you with much more than just your body fat percentage. Plus, the size of our database gives you a very good idea of what is “healthy” and means we can give you a precise target for fat-loss, to within 500g. The DEXA information video below discusses the importance of consistency when it comes to body composition analysis.

What is a healthy body fat percentage?

“Healthy” is very much a qualitative term – healthy food, healthy lifestyle, etc, are not defined by numbers. But quantitative measurements of markers such as heart rate, hormones, blood cells, liver function, etc, will certainly try to paint a person with one set of measurements as “healthier” than another with different results.

When it comes to body fat, having lower fat mass is widely regarded as ‘healthier’ than higher fat mass. Bodyscan subscribes to this view. Being overweight (over-fat) leads to higher levels of visceral fat and that is associated with life-changing diseases such as type-2 diabetes, heart disease, colon cancer, stroke, dementia, as well as undue pressure and wear on the bones. More than 700,000 hospital admissions a year cite obesity as a factor.

So, a lower body fat percentage (actually, a lower fat mass index or FMI – that’s how much body fat you carry in relation to your height, a better measurement) is better than a higher one. Although the actual average fat mass (in kilos/pounds) that men and women carry is quite close, women have a higher body fat percentage than men because they are typically shorter, have less muscle mass and carry more body fat for reproductive reasons. For both sexes, increasing age also tend to lead to high body fat percentages, chiefly from changing lifestyles and lower activity levels.

Bodyscan’s DEXA scan database includes scan data from over 17,000 scans; about 11,000 men and 6,000 women.

As you can see from the percentile tables below, the average (median) score for body fat percentage for men, depending on age, is between 21.3% and 24.7%.

For women, the median BF% is between 30% and 35.9%.

As to what is “healthy”, Bodyscan’s experience is that results at and below the 30th percentile would be “healthy”. In the Bodyscan post-scan consultation, we often provide an arbitrary fat-loss target based on reaching the fat mass index (FMI) in the 25th percentile, which we term “lower body fat.” NOTE: FMI and BF% may not align because of the drawbacks of body fat percentage.

A healthy body fat percentage

Based on reaching the 30th percentile for body fat percentage, you can see from the data tables above that a Bodyscan DEXA result of between 18%-22% body fat for men and 26.5%-31.9% for women, depending on age, we could potentially define as “healthy”.

Need some help?

If you’re looking to understand where you are right now before you embark on a journey to improve your body composition by reducing body fat and therefore your body fat percentage, we strongly suggest you book a Baseline DEXA scan with the full face-to-face consultation. In addition to body scans, we also offer selected customers nutrition plans based on your scan results. If you have any questions visit our Contact page and send us an email from there.

In the meantime you can download our free fat-loss guide here.