Tanita TBF-622 Principles of Estimating Body Fat Percentage, What is body fat percentage, The BIA method, Body fat percentage fluctuations in a day

TBF-622 Body Fat Monitor/Scale

Tanita’s patented “foot-pad” design sends a safe, low-level electrical signal through the body to determine its composition.

Principles of Estimating Body Fat Percentage

The Tanita Body Fat Monitor/Scale TBF-622 allows you to estimate your body fat percentage at home as easily as you measure your weight.

What is body fat percentage?

Body fat percentage is the percentage of fat in your body. Until now, your absolute weight has determined whether or not you were considered overweight or obese. In recent years, the definition of obesity has been refined to mean the presence of excess body fat. Too much body fat has been linked to conditions such as high blood pressure, heart disease, diabetes, cancer, and other disabling conditions.

Body Fat Ranges for Standard Adults1, 2

		Underfat		Healthy	Overfat			Obese
Female 20–39
Age 40–59
60–79
0%	10%		20%	30%			40%
Male 20–39
Age 40–59
60–79
	Underfat		Healthy	Overfat		Obese

1Based on NIH/WHO BMI Guidelines.

2As reported by Gallagher, et al., at NY Obesity Research Center.

To determine the percentage of body fat that is appropriate for your body, consult your physician.

The BIA method

The TBF-622 uses the BIA (Bioelectrical Impedance Analysis) technique. In this method, a safe low-level electrical signal is passed through the body. It is difficult for the signal to flow through fat in the human body, but easy to flow through moisture in the muscle and other body tissues. The difficulty with which a signal flows through a substance is called impedance. So the amount of fat in the body can be accurately estimated by measuring the impedance. The signal used is very low, making it safe and imperceptible.

The illustration on the left show how the signal travels through the body.

					Body fat percentage fluctuations in a day
Body Fat %					Hydration levels in the body may affect body fat readings. Readings are usually highest in the
22					early waking hours, since the body tends to be dehydrated after a long night’s sleep. For the
21					most accurate reading, a person should take a body fat percentage reading at a consistent
					time of day under consistent conditions.
20					Besides this basic cycle of fluctuations in the daily body fat readings, variations may be
19					caused by hydration changes in the body due to eating, drinking, menstruation, illness,
18					exercising, and bathing. Daily body fat readings are unique to each person, and depend upon
					one’s lifestyle, job and activities.
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6 am	10 am	2 pm	6 pm	10 pm Time The graph on the left shows an example of daily body fat percentage fluctuations.

Daily fluctuations in body fat percentage based	Advantages of the Tanita TBF-622
on the BIA method	Previously, body fat percentage was determined by measuring the thickness of subcutaneous
	fat by pinching it with calipers, or by laying a person on a scanning bed and passing a current
	from hand to foot. However, these methods present problems—professional skills are
	required, the procedures take time and are often invasive, and measurement values vary.
	Currently, the gold standard methods of fat percentage measurement are DEXA (dual energy
	x-ray absorptiometry) and Hydrodensitometry (underwater weighing).
	Tanita’s BIA method uses equations derived from large, multi-ethnic population studies to
	predict body composition. Readings taken with Tanita’s TBF-622 correlate highly with both
	DEXA (Tanita’s reference model) and Hydrodensitometry.

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