BIA’s Advantages at a Glance
BIA is much more than a method for fat determination. Because BIA enables you to measure several nutritionally relevant bodily compartments, thus providing a more sophisticated analysis of bodily composition and nutritional status.
The BIA method provides a unique physical advantage: BIA measures the total body water, thus enabling the water balance to be assessed. This is not possible with any of the other »simple methods« for determining the bodily composition, such as infra-red interactance or the calliper method
In conjunction with Jena and Kiel Universities, data on more than 12,000 children and young people have been analysed and the first percentiles developed for body fat and body water from BIA measurements. And the commonly used percentiles for weight, body height and body mass index (BMI) have likewise already been integrated into this method.
This means that the BIA from Data Input GmbH, as a non-invasive and technically uncomplicated method, is ideal for screening growth and weight development—from the age of just 3 years!
Using state-of-the-art, phase-sensitive BIA devices from Data Input GmbH, moreover, you can determine the muscle and organ mass (body cell mass BCM). The widely used non-phase-sensitive devices, such as the commercially available combined BIA scales, do not possess the metrological features required for determining the BCM. This is not possible with most of the simple phase-sensitive devices, such as commercially available household BIA scales.
For assessing the nutritional status, observing progress often provides more meaningful data than taking individual measurements. This approach is conditional on possessing a professional-quality software package, which stores the personal data and the corresponding measurements in permanent memory. The Nutri software from Data Input GmbH manages all the data involved, formulates analyses and trend curves, and is an invaluable aid to diagnostics—even when the period concerned extends over many years.
The Applications for BIA
BIA can be relied on to show the effect of a changed diet on bodily composition.
BIA distinguishes between lipocatabolism and mere water losses.
BIA documents the effect of nutritional errors.
Adiposity and eating disorders:
BIA helps people to become aware of their own bodily composition.
Catabolic process can be detected at any early stage, often before the scales actually show a weight loss.
Kidney diseases and dialysis:
BIA detects extra-cellular hyperhydration or creeping cell losses.
Intestinal diseases (e.g. Morbus Crohn):
BIA detects body water loses from diarrhoea and helps to diagnose malnutrition.
HIV-associated wasting or lipodystrophy:
BIA enables catabolic processes to be detected at an early stage.
Rehabilitation and sport:
BIA measures cell build-up and documents training progress.
Bio-electric impedance analysis is based on measuring the electrical resistance of the human body.
Via electrodes on one hand and foot, a weak, imperceptible electrical field is generated inside the body by means of an impedance analysis device. 2 different electrical resistances are measured here:
- The water resistance R: The electrolyte water of the human body is a good conductor of electric current. The water resistance is used to determine the body water, the lean body mass (fat-free mass) and the body fat.
- State-of-the-art, scientific BIA devices feature what is called »phase-sensitive metrology«, enabling the cell resistance Xc to be measured. This means the body cell mass (BCM) can be determined—an examination that is not possible with other simple methods for measuring the bodily composition, such as the infra-red reactance method.
Measuring equipment and duration
A BIA analysis consists of 2 worksteps:
- Measurements are taken from the prone patient using the BIA device. The patient should remove sufficient clothing to allow a gel electrode to be attached to the hand and foot. The measuring instrument is then connected to the electrodes and the measuring routine is started. Depending on how much clothing the patient takes off, this procedure takes approximately 1 to 2 minutes.
- Entering the figures into the software, and printing out the results. Entry and printout take approximately one minute.
Total time needed for the measuring routine and printing out the results: approximately 2 to 3 minutes.
For the actual measurements, only a couch is needed. The measuring routine is non-invasive, and can be carried out in just a few minutes, even under field conditions. A PC is required for the analysis itself. Evaluating and managing the measurements in a professional EDP program, with an option for individualised progress observation, means that changes in bodily composition can be subjected to differentiated analysis.
Measuring set-up for impedance measurements, with couch, BIA device and PC
At every measurement routine, the parameters determined include the following:
- Body water
- Body fat (in kilograms and per cent)
- Lean mass (fat-free mass)
- Body cell mass BCM
Further parameters, such as the phase angle or the ECM/BCM Index, assist in diagnosing the nutritional status. To facilitate assessment, appropriate tables have been filed in the software, which also creates suitable progress graphics for the major parameters.
Example of an initial analysis using the BIA software NutriPlus©. The individually computed ideal values are always shown to complement the ongoing results.
A Scientific Comparison of Methods
A distinction is drawn between simple and elaborate methods for determining the bodily composition. The elaborate (and expensive) methods include computer tomography or DEXA.
These are contrasted to the »simple, non-invasive methods«, which feature less sophisticated technical equipment and substantially lower costs. The 4 simple methods are:
- Callipers (for measuring the skin fold thickness and thus for calculating the body fat content)
- Infra-red interactance (a method for measuring the thickness of the subcutaneous fatty tissue by means of infra-red absorption and thus calculating the body fat content)
- BIA simple, non-phase-sensitive
- BIA medical, phase-sensitive (such as that provided by Data Input GmbH)
Table 1: List detailing the compartments of the human body that can be determined using the simple, non-invasive methods:
Summary: Only with the phase-sensitive BIA is it possible to simultaneously determine body fat, body water, plus body cell mass BCM and extra-cellular mass ECM.