Additional Information

Further information on body fat is available at our Web site, www.tanita.com and in our educational brochures—call 1-800-TANITA-8 to request a brochure (USA and Canada only).

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 UltimateScale 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 your body that is fat. 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.

The chart below shows four ranges of body fat percentage.

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

1.Based on NIH/WHO BMI Guidelines.

2.As 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

Tanita’s UltimateScale uses the BIA (Bioelectrical Impedance Analysis) method. 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 found in muscle and other lean 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 shows how the signal travels through the body.

Body Fat %

22

21

20

19

18

17

6 am

10 am

2 pm

6 pm

10 pm Time

Daily fluctuations in body fat percentage based

on the BIA method.

Body Fat Percentage Fluctuations in a Day

Hydration levels in the body may affect body fat readings. Readings are usually highest in the early waking hours, since the body tends to be dehydrated after a long night’s sleep. For the most accurate reading, a person should take a body fat percentage reading at a consistent time of day under consistent conditions.

Besides this basic cycle of fluctuations in the daily body fat readings, variations may be caused by hydration changes in the body due to eating, drinking, menstruation, illness, exercising, and bathing. Daily body fat readings are unique to each person, and depend upon one’s lifestyle, job and activities.

The graph on the left shows an example of daily body fat percentage fluctuations.

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