Body Composition Analysis FAQ

Q1. Can patients outside the recommended age range use BIA devices?
Charder's Body Composition Analyzers have a specified age range for measurement accuracy. For example, the recommended age range for best results is between 6 and 85 years old for the MA601 and MA801. This is not due to safety concerns - BIA is safe for all ages, and you can safely measure someone that is outside of the recommended age range with no problem!
Body Composition results need to be validated against gold standards to evaluate accuracy, and improve continuously algorithms. Research ethical boards are understandably averse to approving research that may involve radiation (in the case of DXA) and other risk factors for children, especially those under 6 years old. What's more, a 3-year old may be unable to even reach the hand electrodes, or stand on the device long enough to conduct measurements for data collection. As such, while children under 6 can use Charder'sdevices safely, it is hard to prove with empirical data that the same level of accuracy can be guaranteed for a 2-year old, compared to a 6-year old, or other results within the recommended age range.
The same applies to those over 85 years old - while there are no safety concerns, gathering sufficient measurement data for healthy adults over this age can be difficult, especially for the purposes of data validation, where enough males and females within an age bracket, of various different ethnicities are required. Charder expands the age range only after we have sufficient data, ensuring that we stand by the results provided by our devices.
Q2. Can BIA be used by users with stents?
Patients with embedded electronical medical devices (ex: pacemakers) are prohibited from using Bioelectrical Impedance Analysis (BIA) devices, because of the fear of the electrical current used for measurement affecting the embedded device.

Because stents are not powered by electricity, there is no potential safety risk caused by BIA measurement.

In general, there is the potential for slight measurement inaccuracy if the patient has significant amounts of metal embedded in their body, as metal is highly conductive, which may cause the device to misinterpret results. However, stents are not nearly large enough to make a noticeable difference like a large metal implant in your foot might.
Q3. Do more frequencies mean the device is more accurate?
Not necessarily. It is important for the device to have enough frequencies to calculate body composition results. Generally speaking, 250kHz is recognized to be necessary for reliable ICW:ECW calculations. But beyond that, impedance results might be measured but not used.
Q4. What is the difference between a multi-segmental vs a traditional BIA device?
Hand-to-hand BIA devices measure impedance passed between the arms, and the lower body is estimated based on the impedance measured in the upper body. Conversely, leg-to-leg devices measure impedance passed between the legs, and the upper body is estimated. For subjects with balanced upper and lower bodies, these traditional devices may provide reasonably accurate estimates for whole-body values. However, measurement accuracy is compromised if there is significant upper-lower imbalance (ex: due to top-heavy strength training). More importantly, multi-segment technology allows Charder devices to provide calculations for each segment separately, which is absolutely essential for advanced training and tracking.
Q5. How will results be affected by measurement after exercise?
Exercise can cause a temporary change in impedance, and thus may influence measurement results. Intensive exercise can increase blood circulation that may continue for an extended period of times, and we recommend avoiding measurements shortly after exercise.
Q6. Why does eating and drinking before measurement affect results?
Food and drink may cause temporary changes in weight and impedance. Drinking 1000cc of water will result in a 1kg weight gain. But has this water been absorbed to become part of the body (and thus able to affect impedance), or is it still stored in the stomach? Is undigested food just pure weight?

Temporary weight change will change interpretation of impedance and thus inaccurate results. In addition, it cannot be determined how food affects impedance during the digestion process. Although everyone digests food at a different rate, 2 hours is a general rule of thumb for a certain level of digestion, and thus helping subjects to avoid "measuring immediately after a meal".

To learn more, please view our video guide!
Q7. What printers are compatible with Charder's Body Composition analyzers?

Charder devices are designed to be compatible with Printers that are PCL5 or above. Compatible printer models from several common printer brands can be found below:


A full list of supported printers from different brands can be found here.

Q8. How accurate are Charder's Body Composition analyzers?
Comparing BIA results for Fat-Free Mass (FFM) to DXA is the most common method for validation of device accuracy. Charder's algorithms have demonstrated a r2=0.987 level of correlation with DXA for whole-body FFM. In addition to whole-body measurements, Charder devices are also specially designed to analyze segmental measurements accurately as well, with r2=0.962 with lower limbs.
Q9. Who should not use the Body Composition analyzers, and why?
BIA scans are not recommended for the following groups:
Pregnancy, Nursing Mothers - Body composition algorithms are based on "normal" healthy adults. Because body composition for pregnant women and nursing mothers is relatively inconsistent (particularly body water), results should be used for reference only.
Prosthetics, Amputation - Measurement current needs to pass through both hands and feet to operate correctly. If subject has amputated limbs or prosthetics, the scan will not function correctly.
Embedded Metal - Measurement utilizes electrical conductivity properties of the human body. Metal conductivity is higher than that of body tissue, and may cause inaccurate measurement results.
Q10. How often should I perform a Body Composition test?
Body composition doesn't change significantly day-to-day. While frequency depends on each individual or program's needs, we generally recommend scanning once every 2 weeks to track and monitor progress.
Q11. What should I do to ensure I receive accurate results?
For best results, we recommend following the guidelines below:
No vigorous exercise - Measure before exercise, not after! Exercise affects circulation and body water, which will affect measurement accuracy.
Use the bathroom - The effect of body waste on electrical conductivity is unknown, and may be interpreted as fat mass.
Avoid food and drink 2 hours before measurement - The effect of food and drink (digested and undigested) on electrical conductivity is unknown, and may be interpreted as fat mass.
Input data correctly - Charder body composition analyzers utilize input data (Height, Age, Gender) and measurement data (Weight, Impedance) to measure body composition. If input is incorrect, interpretation of results will also be inaccurate.

For more information, please consult our full recommendation video guide below!
Q12. Why are my results different on other BIA devices?
We do not recommend directly comparing scan results between BIA devices manufactured by different brands. If comparisons must be made, the standard method is to compare your results with those estimated by a "gold standard" device such as DXA.
Both the hardware and software of a BIA device can affect the data used by body composition calculation equations. In addition, each manufacturer uses its own unique algorithms to create proprietary equations, and as such variation between different brands is fairly normal. Therefore, we recommend using your Charder body composition as a baseline measurement, using it to track changes.