Questions about Tanita Body Fat Monitor/Scales
Q:  "How does the Tanita Body Fat Monitor determine my body fat?"
A:  Tanita uses it's own proprietary method of Bioelectrical Impedance Analysis (BIA) (click here for more information).
Q:  "How does the Tanita's BIA compare with other methods in terms of accuracy, repeatability, cost, convenience, and length of procedure?"
A:  There are many methods of estimating body fat. The following is a summary of the most common ones. 
DEXA (Dual Energy X-ray Absorptiometry). Today, this method is considered a gold standard because of its reliability, precision, and the fact that it is based on three body components (fat, muscle, bone) rather than two (fat and muscle) as in most other methods including hydrostatic weighing. It allows fat distribution throughout the entire body to be read in a single scan. The equipment used is very expensive and a person must lie perfectly still for 10-20 minutes while the scan is taken. DEXA is found mainly in research facilities.
Hydrostatic Weighing. Done correctly, this method is also quite accurate and considered a gold standard. However, the test is somewhat subjective because it relies upon the subject's ability to expel all oxygen from their lungs while submerged in a tank of water. Oxygen remaining in the lungs will skew the results. In clinical settings, this procedure is repeated a number of times, and an average is taken. The "tank" is expensive and the inconvenience to the user is considerable. Because of the cost, lengthy testing process, and physical burden to the subject, this method is more suitable for research studies.
Conventional BIA. Bioelectrical impedance analysis uses a very small electrical signal to measure body impedance. The signal is conducted through the water contained in the body. Lean muscle has much more water than fat tissue and allows the signal to pass easily. Fat causes impedance or resistance to the signal. Conventional Bioelectrical Impedance Analysis methods are accurate, though not as convenient as the Tanita BIA method, and may be somewhat subjective based on the placement of electrodes. The user must be in a horizontal position while electrodes and conductive jelly are placed on a wrist and ankle. This procedure is usually performed in a physician's office or clinic. Most conventional BIA manufacturers use hydrostatic weighing as the reference method.
Tanita BIA. Tanita's leg-to-leg version of BIA produces very accurate results that are highly correlated with both DEXA (Tanita's reference method) and hydrostatic weighing. Measurements are very repeatable when tests are performed under consistent conditions. The equipment is not expensive, making Tanita a professionally-accepted method that can be adapted easily for home use. There is no physical imposition to the user; no need for a trained technician to operate the equipment; and the entire procedure takes less than one minute.
Calipers. Skinfold measurements taken by calipers are easy to do, inexpensive, and the method is portable. However, results can be very subjective depending on the skill of the technician and the site(s) measured. The quality of the calipers is also a factor. Inexpensive models sold for home use are usually less accurate than those used by an accredited technician. Additionally, the more obese the subject, the more difficult to "pinch" the skin correctly. Many people find calipers to be uncomfortable and invasive.
NIR (Near Infra-Red). A fiber optic probe measures tissue composition at various sites on the body. This method has become popular because it is simple, fast, non-invasive, and the equipment is relatively inexpensive. However, studies have produced mixed results, and a high degree of error has occurred with very lean and very obese people. Numerous sources report that more research is needed to substantiate this method.
Q: "Why do Tanita Monitor/Scales have different modes? And what are they?"
A:  Please refer to the User Modes Explained page within this Web site.,
Q:  Are there people for whom the monitor is not appropriate?
A:  People with pacemakers are advised not to use the monitors. Although there are no known health risks, this is a precaution that is advocated by all manufacturers of BIA. 

Accuracy is an issue for certain categories of people, but the units may still be used to monitor trends and accurately show degree of change. They include: 
Pregnant women
People who exceed the weight capacity of the scale or exceed 75% body fat
Professional athletes and bodybuilders
 
Q:  "How accurate and reliable are Tanita's Body Fat Monitor/Scales?"
A:  Independent research at several major universities (including Columbia University in New York City) has confirmed that in clinical settings, the Tanita Body Fat Monitor is accurate within +/- 5 percentage of the institutional standard of body composition analysis--Dual Energy X-ray Absorptiometry (DEXA). It should be made clear that there is only one method of calculating body composition that is close to 100% accurate, and that is an autopsy. Tanita believes its method to be the most convenient  and accessible to accurately predict body composition. Tanita's Body Fat Monitor Series results are repeatable to within +/- 1 percent variation when used under consistent conditions. 
Q:  "What conditions might cause skewed results or an "Error" reading in the display?"
A: 
Severe dehydration which may result from alcohol or food consumption, sleep, intense exercise, medication or pre-menstruation.
A very full bladder.
Severe calluses on heels or soles of feet (about 1/400 people tested).
Unclean foot pads may interfere with conductivity.
Nylons interfere with conductivity. If it is absolutely necessary to measure in nylons, use a drop of isopropyl (rubbing) alcohol on the foot pads to act as a conductor.
Q:  "How long will this monitor/scale last me? Is there a warranty?"
A:  The product's length of durability, accuracy, and reliability is measured by the amount of times it is used, not calendar time. All of Tanita's consumer monitor/scales are extremely reliable, providing up to 10,000 uses or more. There is a one-year warranty for parts and labor; an "After Warranty" is also available (see Warranty Card).
Q:  "What type of maintenance is necessary?"
A:  There is simply no maintenance other than the use of alcohol to wipe the foot pads clean and glass cleaner to keep them shiny-always apply to a cloth first and then to the product; avoid soaps. 
Q:  "How will I know if my Tanita Monitor needs recalibrating?"
A:  An "Error" or "Sub" code might appear on the readout; the digital display might not "zero out" after your last measurement; or the results might be erratic and non-repeatable.