What is body fat and body fat percentage?

Body fat is just as essential to the proper functioning of your body as muscle, organs and bones. Body fat provides cushioning and protection, insulation, buoyancy in water and is a natural store of energy.

Your body fat percentage is, quite simply, the percentage (or proportion) of you that is made up of fat. So if you weigh 80kg and you are 25% body fat, it means a quarter of you (20kg) is fat and 80% (60kg) of you is lean mass (muscle, organs, ligaments, skin, etc) and bones.

Among many other indices, a DEXA body scan will provide you with your body fat percentage.

​What should my body fat percentage be?

​Today, our modern sedentary lifestyle means the majority of us carry more fat than we should, and many people’s body fat percentage is way too high. The higher your body fat percentage, the higher your chance of some of this fat being visceral fat (internal fat around your organs), which is associated with life-changing diseases such as heart disease, stroke, colon cancer and even dementia.

Almost two-thirds (64%) of British adults are overweight or obese, and in 2019/20 more than one million hospital admissions recorded obesity (too much body fat) as either the primary or secondary diagnosis. This was an increase of 17% over 2018/19, when there were 876,000 admissions.

The tables below show the ranges of body fat percentage for men and women from 18-59, split into four age bands, measured using DEXA scanning technology. You can see that the median (the yellow 50th percentile) body fat percentage figure for men is between 21.3-24.7%, and for women between 30.0-35.9%.

A low body fat percentage can be taken to be below the 25th percentile, therefore around 17.3-21.0% for males and about 25.5-30.4% for women.

It is healthier to have lower levels of body fat. However, your fat distribution (the way fat is spread around your body) means you will likely carry more fat in some parts of your body (eg, your belly or your thighs) than others.

What’s the best way to measure body fat percentage?

​There are many ways to measure how fat you are, from looking in the mirror to underwater weighing.

But the most accurate and consistent way to measure body fat is known as DEXA (dual-energy X-ray absorptiometry). A DEXA scan uses very low-dose X-rays to give you extremely precise measurements of your body fat, lean body mass and bone mass. DEXA is a medical-grade technology used in hospitals and sports science research labs.

Note that different methods of measuring body composition will give different results, so do not compare your own DEXA body fat result with what you see in magazines or with others who have been measured by less reliable methods, such as skin-fold calipers. As well as its precision, DEXA is the very best method when it comes to consistency and reliability.

How do I calculate how many calories I need for fat-loss?

​For all the money spent on diet books, supplements, boot camps and meal replacements, there is only one way to lose body fat, and the results are guaranteed.

To lose body fat you need to be in a “calorie deficit”.  That simply means you need to eat and drink fewer calories (ie, consumer less energy) than you burn in your daily activities. ​If your “calories in” is the same as your “calories out” then your weight will stay the same. This is known as “eating at maintenance“.

If you are gaining weight, it means you are in a “calorie surplus” – you are consuming more calories than your body burns. To stop the weight gain and begin losing weight, you have to eat less or become more active, or both. Eating less will have a much greater impact than exercise on its own.

A DEXA scan will enable you to calculate how many calories you can eat to lose body fat. It’s also the best method for telling you how much fat you actually need to shift in the first place to get your body fat percentage down to a healthy level. This video explains why a DEXA scan is the best method for calculating the calories you need, as opposed to the usual formulas that simply use age, sex, weight and height.

Without a DEXA scan, you can get a good idea but you’ll have to guess how much body fat you need to lose and you’re likely to overestimate the amount of activity you do. The data from a DEXA scan and the experience of Bodyscan’s body composition consultants will give you the best possible data (and motivation!)

Get a DEXA body scan at Bodyscan!

​Bodyscan is the UK’s biggest and best DEXA body scan service, with two clinics in London. We’ve performed over 17,000 scans and helped thousands of people on the road to a healthier body fat percentage.

The word most often used by clients is ‘eye-opening’ and you can read the Google reviews for both locations here.

We recommend repeat scans every 12 weeks to check your progress. That’s short enough to see some change and keep you motivated, and long enough to be sure that what you are doing is sustainable; in other words that you can stick to your eating and activity plan. 

See you at Bodyscan soon!