Weight says little about how our body looks. A man can be a mountain of muscles with 90 kilograms – or chubby. The body fat percentage is decisive for the visual impression. But how do you determine this? Two methods in particular are informative and practical, but have their pitfalls. FITBOOK presents the possibilities of body fat measurement.
First of all: It is not that easy to reliably measure the body fat percentage. This is mainly due to the fact that fat is not only visible and measurable from the outside, but also encloses organs and can therefore not be hidden in the body for us to see. In addition, fat is distributed differently in each person due to genetics. Some tend to collect it on their hips, others on their stomach or buttocks. Belly fat is classified as particularly unhealthy.
Therefore, the range is large when it comes to which body fat percentage is still considered healthy. The reference values that were determined in a study from the year 2000 at the US Columbia University with 1600 adult subjects are often used for classification.
Body fat optimal values for men
- 20-39 years old: 8-20%
- 40-59 years old: 11-22%
- 60-78 years old: 13-25%
Body fat optimal values for women
- 20-39 years old: 21-33%
- 40-59 years old: 23-35%
- 60-79 years old: 24-36%
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Measure body fat percentage – the different methods
There are very different fat analysis methods: In densitometry, for example, body density is determined by underwater weighing. The proportion of fat and muscle can be calculated using the ratio of body mass to body volume. Although this method is very accurate, it is also very complex and can only be carried out under laboratory conditions in a water tank.
Body fat can also be measured very precisely using MRI (magnetic resonance imaging) – the method is even considered the scientific gold standard due to its high reliability. However, the costs are considerable: Depending on the device, an hour of measurement can be between 400 and 2000 euros. The evaluation is only possible by experts.
Two of the simplest and cheapest measurement methods are bioelectrical impedance analysis (BIA) and calipometry. Both can be done at home or at the sports doctor’s in just a few minutes. FITBOOK presents them in more detail with their advantages and disadvantages.
Also interesting: Why the body fat percentage increases when you lose weight quickly
Bioelectrical impedance analysis: measurement using body fat scales
Body fat scales are particularly practical because they promise a quick measurement. A light current impulse is sent through the body via the soles of the feet. This method is called Bioelectrical Impedance Analysis (BIA). Since fat and water have different resistances, the scale uses an algorithm to calculate the proportion of each mass in the body.
«Muscle tissue has a lower resistance than fatty tissue and is therefore a good electrical conductor,» says Eduard Isenmann about FITBOOK. He is a research associate in the fitness and health department at the IST University and in the cardiovascular research and sports medicine department at the German Sport University in Cologne.
The problem: Since the electrodes are usually on the feet, they only measure the abdomen. Although one can draw conclusions about the entire body from this result, this value is relatively imprecise. «Since electrical current seeks the path of least resistance, it is important to attach the electrodes not only to the hands or only to the feet, but to the hands and feet on the same side in order to obtain an analysis of the entire side of the body,» says expert Isenmann .
Significantly more reliable are scales that also conduct the current impulses via sensors on the hands. The upper body is also included in the measurement.
But what you have to consider when taking measurements is that the fat-water composition in the body changes over the course of the day. In order to have reliable comparative values, you should always measure at the same time and under similar conditions. «It is important for this type of examination that there are no electrical conductors on the body and that the subject is not dehydrated, i.e. has not consumed alcohol in the last 48 hours and has not had any extreme physical exertion,» explains Isenmann.
It is best to always take the measurement in the morning after getting up, before eating and drinking and with an empty bladder. Hands and feet should be dry and not creamed.
Advantages of Bioelectrical Impedance Analysis
+ works very fast
+ Body fat scales are available for at home
Disadvantages of bioelectrical impedance analysis
– Values can vary greatly depending on the body’s water balance
– Algorithms of the scales not transparent
– only professional scales deliver good results
You can find even more information about body fat trolleys on our partner portal TECHBOOK.
Measure body fat percentage using calipometry
Measuring body fat using the so-called calipometric method is more precise but also more complex. A skin fold measuring device, the caliper (a kind of forceps), is used to determine the subcutaneous tissue. The procedure is as follows: On at least three specified parts of the body (three-fold formula), a section of skin measuring three to five centimeters is grasped with the thumb and forefinger and pressed together to form a fold. This is then measured with the caliper. The values are then entered into an online tool or a smartphone app and the body fat percentage is calculated from them.
The challenge here is a precise procedure for the measurement. You should always grab a skin area of the same size in the same place in order to achieve exact comparison values. “It takes some practice to ensure objectivity. As a rule, this measuring method should always be carried out by the same person and the measurements should be documented as precisely as possible,” explains Isenmann.
You can do a fat measurement with a caliper yourself or at the doctor’s. He has more experience with the measuring method and can therefore determine more reliable values. Photo: Getty Images
With the three-fold method with measuring points on the stomach, biceps and thighs, it is still possible to carry out a measurement on your own body. The more measuring points are added (four-, five-, seven- or nine-fold method), which can also be in the shoulder blade area, on the triceps and back, you need the help of a second person. The caliper usually comes with precise instructions for use with the measuring points.
Also interesting: muscle or fat – what weighs more on the scales?
However, the results also vary here and are very dependent on the correct measurement. According to Isenmann, factors such as decreasing elasticity of fatty tissue with age, skin thickness, certain phases of menstruation (water-binding phases) and being very overweight can also have a negative impact on the values.
If you want to be on the safe side, you can have such a measurement carried out by a sports doctor. The low acquisition costs speak for private use: calipers are available for less than ten euros, while good fat measuring scales cost at least 75 euros.
advantages
+ low acquisition costs
+ the more measuring points, the more reliable the values
Disadvantages
– an assistant is required for many measuring points
– Values depend very much on the exact measurement
– best carried out by a sports doctor
The abs tip
Ultimately, both the bioelectrical impedance analysis using the body fat scale and the wrinkle measurement using the caliper only provide an orientation value, but not an absolutely reliable value. Whether you have ten or 15 percent body fat as a young man is not decisive for your health, because both values are in the optimal range.
There is also a tip for assessment, because the body fat percentage can be roughly estimated visually and haptically relatively easily. Once the abs are showing or palpable, it’s a reliable indicator of relatively low body fat.
Also interesting: Almost everyone has a six-pack with this exercise
But you shouldn’t overdo it, because too little body fat is also unhealthy – and can damage the hormone balance, weaken the immune system and you freeze much faster. For men, the healthy lower limit is about ten percent, for women about 15 percent.
The conclusion of our expert Eduard Isenmann: «If the fat content is between 10 and 25 percent in men and between 15 and 30 percent in women, that’s perfectly fine. However, if the fat content is higher or lower in the long term, this can be hazardous to health, depending on the individual.”