How Can a Scale Measure Body Fat

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Gone are the days when you step on a scale, and it will just show you your weight. Frankly speaking, we can only see those manual scales in the doctor’s office which are called upright scales. Today, we now have body analyzers that can also show your body mass index, bone mass, basal metabolic rate, water mass, and other health measurements. But surely, you must be wondering, how can a scale measure body fat?

If you think about it, scales do not really scan our body, right? They just somehow have an automatic estimate of what our body condition is. How do they do that?

It is really amazing to think that technology is so advanced that even the measure of something internal that does not really manifest too much externally can be measured by just stepping on the scale.

With that said, we shall discuss how can a scale measure body fat. For us to know that, we will also talk about how these scales work and what technology is responsible for measuring the fat. Lastly, we will discuss how you can use to your advantage the body fat measurements obtained.

How Can a Scale Measure Body Fat?

The technology that is behind all these accurate internal measurements is bioelectrical impedance. The idea behind this is that a body analyzer scale will send out a low electric current throughout our body.

That is a bit scary, right? Do not fret as these currents are totally safe. However, it is not really recommended for pregnant women or those people who have an electric implant to use such scales.

The shot of electric current is used because they flow faster through muscle and water compared to fat and bone. Therefore, it is not your fat that is measured, but the speed of the current. Once the scale measures the rate of the current, it will then estimate how much body fat you have based on a formula.

How accurate is this?

It is accurate when used in a series of measurements, but for single use, you really cannot say if what is displayed is right. This is the case since body fat measurements can vary when they are taken immediately after or shortly after taking a meal. The variation would be more or less 4.2% of body fat.

Another thing to note is that moderate exercises can also affect the measurement which means there will be an overestimation of fat-free mass. On the other hand, there will also be an underestimation of the percentage of body fat due to the reduced impedance.

Other than this, there are also factors that might affect the estimation. So the bottom line is, if you really want accurate results when you want to measure your body fat, you should at least measure it three times on different occasions, and then compute the average.

What Other Factors Affect the Accuracy of the Body Fat Measurement?

Other than the two cases that we discussed earlier, there are also certain situations that will highly affect the measurement.

  • Muscle: When you do weight training, you gain more muscles. Therefore, muscles will weigh more than fat. So if you are under this workout program, your body fat percentage will not be accurate.
  • Fluid intake: Water is important as it is the means of transportation of the electric current. So if you are dehydrated, this will change your reading. The same is true when your body has too much liquid.
  • Menstrual cycle: Usually, there is a lot of water retention when a woman is on her period, and the result is a lower reading.
  • Movement: We are working with sensors here so you should always stay still. Also, do not quickly step on the scale as this can interfere with the reading.
  • Foot calluses: As crazy as it may sound, some studies that showed having thick foot calluses will affect the flow of the electric currents.

What is the Importance of Knowing Body Fat Percentage?

You might be thinking why you should know your body fat measurement even if you are not undergoing a weight loss program or a bulking-up program. Actually, this information is extremely relevant since knowing your body fat percentage will lead you to know if what you have is the proper amount of fat or the dangerous amount of fat.

Of course, too much bad fat can lead to hypertension, heart disease, diabetes, and other illnesses. The same goes for having too little fat. Another important point is the saying “looks can be deceiving.” You might not lose or maintain your weight even if you are thin because, in reality, fat can be found in different places of the body that cannot be seen physically.

So with this knowledge, you will also know if you have to exercise regularly, or what type of workout you should do.

What are Other Ways of Measuring Body Fat?

We are not saying that bioelectrical impedance would fail us, but you are now aware that there might be inconsistencies. So, here are other options:

  • Handheld BIA device: This works much like the BIA scale, but research suggests that the electric flow will be better when the source is your hands.
  • Calipers: With this device, the thickness of certain parts of your body will be measured and calculated together with your age and gender.
  • Bod Pod: Professional athletes use this and it uses air and its volume to calculate your body fat
  • Hydrostatic Weighing: This can be arduous as you really have to be in a pool and go underwater. You will then expel as much air as you can while a machine weighs you.
  • InBody: This is a combination of a BIA device and hydrostatic weighing.

Final Words

Yes, it can be sad to know if you are going off the rails in terms of having a good amount of fat, but with the use of BIA scales, you can now monitor them and use it to your advantage to adjust your exercises and meals. Just keep in mind that you should least measure it at least three times for accuracy.

Related: Best BMI Scales

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