Frequently Asked Questions

I see that OMRON produces three different types of Body Composition Monitors, what are the differences? Is one better than the other?

The three types are ‘hand to hand’, ‘foot to foot’ and ‘hands to feet’. In the ‘hand to hand’ method only the upper portion of the body is measured. These values can vary significantly during the course of the day. In the ‘foot to foot’ method the lower portion of the body is measured. As with the ‘hand to hand’ method, these values can vary significantly during the day. The ‘hands to feet’ method takes the whole body into account and therefore provides a more accurate measurement than the other two methods. Also, the value deviation during the day is much less compared to the other two methods.
All three types provide an accurate picture of your Body Fat as well as the Body Mass Index (BMI). The possible differences between the three are minimal if one were to do a side by side comparison at any given time. Bear in mind that as with any monitoring procedure be it blood pressure, temperature or body composition – being consistent (= time of day), is the most important factor

Is there a recommended time to take a measurement of your body fat?

We recommend you to take the measurement in the morning before you exercise, eat, drink or take a shower. This will give you an opportunity to develop a trend and a good day by day comparison. Please bear in mind that during the course of the day water levels tend to decrease. This impacts the various measurement methods.
The hand to hand method gives an increasingly fattier result in the course of the day.

In contrast to this, the foot to foot method gives an increasingly muscular result.

The total body method shows an even measurement result throughout the day.

Hand to Hand method

Hand to Feet (total body) method

Foot to Foot method

What is the Bioelectrical Impedance Method?

Bioelectrical Impedance (BI) is considered one of the most accurate and accessible methods of screening body fat. Muscles, blood vessels and bones are body tissues having a high water content that conduct electricity easily. Body fat is tissue that has little electric conductivity. The Body Composition Monitor sends an extremely weak electrical current (0.5mA), through your body to determine the amount of fat tissue. The weak electrical current is not felt while operating the Body Composition Monitor. The body fat percentage is calculated by a formula that includes five factors; electrical resistance, height, weight, age and gender.

What is Body Mass Index?

It is a measure for assessing a person’s body weight. Since overweight is a growing global problem, the Body Mass Index is used to point out the associated risks.
However, BMI only provides a rough guide value and it is disputed since it does not take into account a persons build or the composition of the body weight in terms of fatty and muscle tissue, which vary by individual.

How accurate are Body Composition Monitors?

Three factors need to be taken into account. One is the accuracy of the display, the second is accuracy of the measurement calculation (Body Fat Percentage), and lastly how the device is being used (time of day, physical state, etc.).
Display accuracy is typically 0.1%. The accuracy of measurement varies from model to model between +/- 3.5 and 4.1% based on the Standard Error of Estimation (SEE). The SEE states that; 68% of the measurements for different users are accurate to within +/- 3.5 to 4.1% (model dependent), relative to the body fat percentage.
Body Mass Index (BMI), only provides a rough guide value and it is disputed since it does not take into account a persons build or the composition of the body weight in terms of fatty and muscle tissue, which vary by individual. BMI uses a very simple formula to calculate the value; weight divided by the height squared (kg/m²).

Can you use a Body Composition Monitor if pregnant?

Since Body Composition Monitors measure the electrical conductivity of the soft tissues of the human body, this conductivity (and thus the calculated fat %) may be influenced by the large amount of fluid a woman carries during her pregnancy.

Secondly, since the weight of the pregnant woman is also significantly higher than normal, this may also influence the final estimation of the fat %

Why can a Body Composition Monitor not be used by body builders?

The estimation formula in the device is based on a large study of 'normal' muscular subjects only. Body-builders were not included in this (validation) study. Therefore due to the different body-composition properties of body-builders, the indicated fat % may not be reliable.

Secondly, OMRON Body Composition Monitors make an estimation of body fat %, based on a number of parameters:
Electrical impedance (measured by the device)
Height of the person (input by user)
Weight of the person (input by user)
Age of the person and (input by user)
Gender of the person (input by user)
If body builders were to measure their fat % by means of the BIA (Bio Impedance Analysis) method, the large amount of muscle tissue and low water-content, the measured impedance will be relatively low and possibly unstable. However, since body-weight also contributes significantly to the calculation and body-weight is relatively high for body-builders, the final measured fat % will be too low and unstable and thus unpredictable.

I understand the Body Composition Monitors use an electric current to measure body fat. Is this electric current dangerous?

OMRON Body Composition Monitors pass a very weak alternating current (50 kHz, 0.5 mA [milliamp]) through the body.

This is absolutely safe.
However, for wearers of electronic medical devices and implants (pacemakers, electrocardiograms, etc.), this current may cause a malfunction. This group of people is strongly advised NOT to use these monitors.

Why should a Body Composition Monitor not be used when you have a cardiac pacemaker?

Any Body Composition Monitor based on the BIA (Bio Impedance Analysis) principle, sends a weak electrical current through the body. This electrical current cannot be sensed by a person, but a cardiac pacemaker may pickup the signal and could become unpredictable.

What is the "anaerobic zone"?

The "anaerobic zone" is only intended for ultra athletes. It is to be used only with medical approval and close supervision. Typically used for interval training to improve or measure endurance and intended for those in extremely good physical condition, during races or training for competition.

Where can I find additional information about my Body Composition Monitor?

The Instruction Manual contains a wealth of information. In case you have lost the instruction manual of your device you can download it from the support section.