Regarding Bioelectrical Impedance Analysis
If you have any questions about the MA801 relating to scientific basis not addressed in the FAQ,
please contact us at the following E-mail address:
E-mail: [email protected]
1. How are Body Composition results measured?
Bioelectrical Impedance Analysis (BIA) is a non-invasive measurement of body composition,
based on the fact that the human body consists of conductors and non-conductors. Water
(which comprises a significant proportion of muscle) is a good conductor of electricity, where
fat is a non-conductor. A small, safe, electric current (AC) is sent through the subject's body. It
measures the different levels of resistance (impedance) as it passes through different types of
body tissue. These impedance values are then translated using clinically validated algorithms
into estimations of water, protein minerals, muscle, and fat. With multiple frequencies, more
detailed information - such as water inside and outside cells - can be analyzed. Each BIA
device and brand uses a different set of algorithms, which is why measurement results may
differ when using different devices.
The most common validation of accuracy is with DXA, though other methods such as MRI and
CT are used in some studies. The most appropriate validation standard depends upon what
type of composition is measured.
2. Is BIA safe for everyone?
Individuals with implanted medical devices such as pacemakers, defibrillators, or other internal
medical devices should not use BIA machines. A low level electrical current is sent through the
body during measurement, which may have a potentially disruptive effect on the implanted
device.
In addition, BIA measurements can be conducted for the following populations, but there may
be difficulties in measurement and drop in result accuracy:
■ Individuals that are outside the permissible range of measurements (above 300kg) may
receive less accurate results, due to insufficient research data.
■ Women undergo a wide range of body composition changes during pregnancy, including
but not limited to change in fat percentage and body water, which can affect the accuracy
of BIA results.
■ Individuals who cannot hold onto the hand electrodes during testing may find it difficult to
complete measurements.
■ Individuals with prosthetics/amputations cannot complete measurements, as BIA requires
contact with all 8 electrodes (2 for each hand and 2 for each foot).
■ Individuals with embedded metal may receive inaccurate results, as BIA may interpret highly
conductive metal as body water, affecting results.
3. Is the electric current harmful to the body ?
Aside from users with implanted medical device, no scientific research has been published
cautioning against bioelectrical impedance analysis. In fact, there are proven studies
confirming the safety of BIA for the human body. “Bioelectrical impedance analysis (BIA) is a
technique that has proven to be safe, generally acceptable to patients, and easy to use
[109,110]. (Nutritional Management of Renal Disease, 2013)”
4. Can I wear jewelry, watches, or other metallic ornaments during measurement?
Metal objects may interfere with the electrical current used during testing, affecting
measurement accuracy. In addition, heavy clothing or accessories (if not corrected for on the
weighing screen) will affect the body composition analysis results, as the weight will be
interpreted as body weight.
5. How often should I perform body composition tests?
Changes in body composition from physical training - such as reduced fat mass and increased
fat-free mass - are not immediate. For effective tracking of progress, we recommend
measuring body composition at least once every two to four weeks.
6. How can I get the most accurate results?
For best results, Body Composition Analysis should be conducted under the same conditions
every time. Inconsistent measuring conditions will affect the accuracy and validity of BIA
results, as the distribution of body fluids can influence the body's impedance and reactance.
Before measurement, please take note of the following:
■ Avoid exercise or strenuous physical tasks 12 hours before measurement.
■ Avoid eating before measurement. Allow 2 hours for digestion.
■ Avoid alcohol 12 hours before measurement.
■ Use the bathroom before measurement.
■ Take off metallic ornaments and jewelry before measurement.
■ Clean hand and foot electrodes before measurement.
■ Remove shoes and socks before measurement.
■ Avoid excessively tight clothing that may interfere with blood circulation.
XII. FREQUENTLY ASKED QUESTIONS (FAQ)
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■ Avoid physical contact with other people or objects during measurement.
■ Avoid talking, and try to hold still as possible during measurement.
■ Perform the measurement in the morning.
■ Perform the measurement under normal temperature conditions (24-28°C).
7. The measurement results seem incorrect?
Body composition varies throughout the day, and results are often affected by water
distribution, especially strenuous physical activities that may change water distribution in your
body. Make sure that you have followed all the steps in Question 6 above before and during
measurement.
If results appear noticeably different from a previous measurement or other body composition
measurements (such as DXA or Air Displacement Plethysmography), please check the
Impedance values. If the impedance between the subject's left and right arms (or legs) is
significant, it is likely a measurement error has occurred. Please conduct another measurement.