Knowledge Base

What is Bioelectrical Impedance Spectroscopy?

Bioelectrical impedance spectroscopy (BIS) is a non-invasive analysis method used to build a detailed picture of body composition.

This information can be used across a range of health and fitness and medical applications, offering information on hydration levels, muscle mass and body fat percentage for medical patients, professional athletes, and fitness enthusiasts.

Carried out with portable equipment, bioelectrical impedance spectroscopy can be undertaken at convenient and regular intervals to monitor and manage body composition and wider health conditions.

How Does Bioelectrical Impedance Spectroscopy Work?

Bioelectrical impedance spectroscopy works by sending a low-level electrical current through the body and measuring the impedance (resistance) to the flow of this current - spectroscopy does this across 50 frequencies. BIS calculates body composition and hydrational values using Cole-Cole analysis.

After analysis, a summary of the values are displayed. These include; fat, water and lean tissue (fat free tissue). Allowing for a full the estimation of body composition and a detailed look at the patients health.

With Bodystat’s Multiscan 5000, this procedure can be undertaken at the bed-side if required for complete ease and comfort to the person being measured.

Advantages of Bioelectrical Impedance Spectroscopy

Several methods are employed to perform body composition analysis, providing detailed insights into the proportion of fat, muscle and bone in the body. One of the most accurate methods is the DXA/DEXA Scan that employs x-ray technology to assess muscle and fat mass and bone density.

Similarly, bioelectrical impedance devices are used to measure fat, water and lean tissue. Skinfold measurements, taken with callipers, provide a painless way to get body fat readings. Hydrostatic weighing, another method, calculates body composition using water displacement.

These various methods give a thorough understanding of one's body composition, aiding in setting health and fitness goals.

What Information Does BIS Measure?

Bioelectrical impedance spectroscopy measures:

Body composition: This is the percentage of fat, bone, and muscle in your body.
Hydration/fluid status: The balance of fluid between the Intracellular Water (ICW )& Extracellular Water (ECW) space. This is measured in litres plus normal ranges.
Hypervolemia: Refers to fluid overload, or too much fluid, in the body. Volume of overhydration is measured in litres.
Cellular health: Phase Angle, predication marker, cell membrane capacitance and characteristic frequency.

How Can this Data be Used?

The data from BIS can be used to build an accurate profile of what’s going on inside the body; this means you’re able to track if interventions are being successful or not.

Data gathered can be used to determine the body’s percentage of fat and lean tissue, as well as dry lean weight, skeletal muscle mass, and body cell mass.

These measurements can also determine extracellular water (ECW) and intracellular water (ICW) separately; this can give more precise insights into what’s happening at a cellular level.

By comparing this data to normal ranges, the information can be used to determine the health and fitness status of the person being measured.

In particular, the Bodystat Multiscan 5000 can be used to combat Disease Related Malnutrition (DRM). In all diseases, deconditioning of the body happens; this is shown as a loss in lean mass, fluid imbalance and a deterioration of cellular health - which all leads to worse outcomes.

Which Sectors Can Benefit From BIS?

One of the largest uses of BIS is in the medical sector, where it can play a critical role in cardiac, renal, pulmonary, oncology and gastrointestinal health as well as in managing obesity and monitoring hydration.

Role of BIS in Cardiac Health

Fluid overload can cause increased pressure on the heart which can ultimately lead to failure.

Bioelectrical impedance spectroscopy plays an important part in monitoring/managing fluid overload to aid prevention and treatment.

However, BIS is not recommended for those with a pacemaker fitted, due to concerns around interference.

BIS in Managing Obesity and Related Health Conditions

BIS can build a more detailed picture of an individual’s body fat index by detecting changes in body composition. This is in comparison to other popular methods of assessing weight, such as scales and body mass index (BMI), which do not offer the same levels of analysis and cant distinguish between different bodily compartments, revealing only quantity of weight rather than quality.

Importantly, BIS can show body compartments, which can help identify sarcopenia in obese patients. It also gives an indication of what’s happening at a cellular level which could indicate whether obese patients are malnourished.

BIS and Hydration Status Monitoring

With the ability to provide data on fluid levels in the body, BIS can be used to indicate hydration levels – overhydration and underhydration. For example, this can be particularly useful to help determine a patient's dry weight on dialysis and monitor their nutritional status.

For example, many patients with Chronic Kidney Disease (CKD), particularly at stage 4 and 5, are malnourished. The Multiscan 5000 may be used to detect malnutrition in patients with normal or high body fat by an assessment of body cell mass. Body cell mass can easily be obscured by an expansion of extracellular fluid which will not be detected by looking at an overall increase in total body weight.

Overweight woman looking at a bioelectrical impedance spectroscopy report and smiling

Bioelectrical Impedance Spectroscopy in the Pharmaceutical Sector

A final use of BIS is in the pharmaceutical sector, with applications including examining drug-body interactions and the development of personalised medicine.

Pharmacist using body composition data to determine minimum effective dose.

Use of BIS in Understanding Drug-Body Interactions

BIS can be used to help guide drug dosing based on the metabolically active (lean) tissue in the body. It can also be used to help track the drug effectiveness depending on the goal of said drug/if there are any side effects.

BIS can be beneficial particularly in pharmaceutical applications to determine factors such as minimum effective dose. With doses tailored to an individual patient, risks of side effects can be reduced and ultimately contribute to overall drug safety and effectiveness.

Potential of BIS in Personalised Medicine

Personalised, or patient-centred, medicine is becoming increasingly prevalent, and refers to medical intervention based upon an individual’s genetic profile, as opposed to a more generalised approach. This can include doses suited to a particular patient thanks to being able to determine minimum effective doses.

Whether for medical applications or health and fitness, bioelectrical impedance spectroscopy is a quick, convenient, and non-invasive method of estimating body composition. Offering a more detailed analysis than comparative procedures, BIS and body composition analysis equipment can be crucial to monitoring and managing health.