Is the bioimpedance scale reliable? How to use it correctly

When used correctly, yes, the bioimpedance scale is reliable and can be used as a tool to create a reference to see the current state of things or measure your progress, especially if always used under the same conditions (fasting, always using it at the same time and with the same hydration level).

The most important issue, and where most people fail, is understanding its real purpose, how it works, how and which one to use, and thus obtain reliable results.

The bioimpedance scale is a tool used to estimate a person's body composition.

In addition to measuring body weight like a traditional scale, it tries to calculate the percentage of body fat, the amount of muscle mass, the amount of water in the body, the basal metabolic rate, among other data (it depends on the model used).

This data is especially useful for those who want to measure progress in body change projects, whether to gain muscle mass or lose fat, allowing you to create benchmarks for routine adjustments.

For example, if you're following a fat loss plan and use the scale under the same conditions every week, you can see more clearly if changes are occurring and make the necessary adjustments if the opposite is happening.

The bioimpedance scale works by measuring the body's electrical resistance through a process called bioimpedance.

When a user stands on the scale with both feet, a weak electrical signal is sent to the body.

This signal travels through tissues that contain water, such as muscle and blood, and faces greater resistance when passing through body tissues such as body fat and muscle mass.

By measuring the speed at which this electrical signal is conducted through the body, the scale attempts to estimate the body fat percentage, the amount of muscle mass and fat.

Depending on the scale, this may be done in conjunction with other data, such as height, age and gender, which are entered by the user.

Is the bioimpedance scale reliable and accurate?

A bioimpedance scale can be quite reliable when used correctly, but that does not necessarily mean it is accurate.

This distinction is important, as someone may unfairly condemn the device by expecting functionality that the device will never deliver.

You saw in the text itself that the scale works by sending electrical signals through the body, which travel through places where there is liquid, while encountering resistance where there is none.

This means that any changes in hydration levels and other factors involving how the body retains fluids throughout the day affect the scale results.

For example, if for any number of reasons you have less water in your body (dehydrated, exercised a lot, hot weather, etc.), the scale may say you have more fat than you actually do.

After all, with less water in the body, the signal will travel with more difficulty, assuming that this greater resistance is caused by there being more mass (fat or lean), generating a result that disregards factors that affect hydration levels.

In other words, accuracy is not the scale's strong point, but its reliability is a separate matter and does not directly depend on accuracy, in the literal sense of the word.

See, as long as it's a device that fulfills its basic purpose, which is to send an electrical signal through the body, and the measurements are always taken under the most similar conditions possible, this will generate a result that, regardless of whether it's accurate or not, can be used as a reference to measure progress.

In other words, if you are on a plan to change your body, always use the scale under similar conditions and are seeing the results on the device change towards your goal, this is a clear sign of progress.

To make this issue even clearer, imagine that you have a tape measure with a manufacturing defect, where each centimeter is actually 1.5 centimeters.

When measuring your abdominal circumference, you will get an inaccurate result.

However, if your goal is to lose inches and you continue measuring your abdomen with this faulty tape every week and notice that you are losing inches, this will still be a valid parameter to evaluate your progress.

Using the bioimpedance process as a progress meter is the same thing.

Now, if you are using the device for health reasons, because for some reason you need to know exactly how much muscle mass and fat you have, then it is better to look for other methods.

Honestly, it's not worth making a big investment in this type of device (more on that later).

However, as mentioned, when used well, it still serves as a valid estimate for measuring your progress.

With that in mind, if you're interested and don't know which scale to buy, I would recommend the BioHealth model from Multilaser , which, by all indications, offers excellent value for money.

This device in question has over 3,600 reviews, and almost every reviewer would give it a top rating on Amazon (use this as a guide; do your own homework before making any deals).

How to use the bioimpedance scale correctly

Use the bioimpedance scale once a week, after waking up, on an empty stomach, and wearing only underwear. It's essential that subsequent measurements are taken exactly the same way—under the same circumstances.

As already mentioned, regardless of the accuracy of the device, it is still a useful tool for monitoring weight and body fat percentage.

So, the first step is to not worry about your initial reading and the actual number you get from the scale. If the scale says you're 20% fat, but you think you're less, that's irrelevant. Instead, use it as a way to track changes over time—once a week, as mentioned above.

Finally, always read the instruction manual before using a body composition scale. There may be safety warnings for people who are pregnant or have a pacemaker or implanted defibrillator.

Assuming you want to monitor your progress (which really matters in practice), the best alternative to this type of scale is a tape measure and visual monitoring .

First, a tape measure is a simple and accessible tool that allows you to accurately measure the circumference of various body parts, such as the waist, hips, arms, and thighs. These measurements are extremely useful for tracking changes in body composition over time.

For example, a reduction in waist circumference can be an effective indicator of abdominal fat loss, while an increase in arm circumference can reflect muscle gain. These measurements are concrete and provide reliable data on progress.

On the other hand, visual assessment, while subjective, offers an immediate global perspective on physical changes. For example, if you're aiming to lose fat but your weight isn't budging on the scale, the mirror may show that you're becoming more defined and your weight is stagnant because you've actually gained muscle mass and lost fat.

Additionally, you can take before-and-after photos to make more accurate and realistic comparisons. For example, if every two weeks you take photos of your body using the same circumstances (same angle, waking up on an empty stomach) and looking at the photos you can see progress, then no number matters.

Finally, you can use both (the tape and the mirror) to generate even more accurate measurements to assess your progress.