1. Important Facts about Body Composition
It is important to know the body composition of an individual in
order to be able to estimate his/her health condition. Actually, it
is not enough to know one's weight but it is necessary to define
its quality, which means dividing the human body in its two major
component masses:
• lean body mass: bones, muscles, viscera, water, organs, blood
• fat body mass: adipose cells
Under the same conditions of weight, these two masses have
different volumes.
By means of electrodes placed on the platform, the scale sends a
weak low intensity electric current that passes through the body
mass. The electric current reacts in a different way according to
the masses it passes through: the lean body mass opposes a weak
resistance, while the fat body mass has a greater resistance. This
body resistance, called bioelectrical impedance, varies also in
function of sex, age and height.
For a correct control of one's ideal weight, it is important, besides
the weight, to compare the body fat percentage calculated by the
scale, with the parameters contained in the table and the body
water percentage, with the information listed hereinafter.
If the percentages are outside the normal values, we
suggest you consult your physician.
In order to better understand the value of your body fat
percentage, we suggest you write down this value for a given
period of time. In order to obtain a valid comparison, you should
weigh yourself always at the same time of the day and under the
same conditions.
Body fat mass percentage
The percentage of fat listed in the following table represents the
total fat, calculated by summing up the essential fat (or primary
fat) and the spare fat (or storage fat). The essential fat is neces-
sary since it is needed for the metabolism.
The percentage of this fat is different between the two sexes:
about 4 % for men and about 12 % for women (percentage calcu-
lated on the total body weight).
The spare fat, which is theoretically superfluous, is necessary for
those who carry out physical activities. Even in this case, the fat
percentage is different between the two sexes: 12 % for men,
15 % for women (percentage calculated on the total body weight).
Therefore, the normal percentage of fat mass on the body weight
is approximately 16 % for men and 27 % for women.
Such percentages differ with the person's age as shown in the
table here below.
Women Excellent Good
Age
≤ 19
17.0
17.1-22.0 22.1-27.0 27.1-32.0 > 32.1
20-29
18.0
18.1-23.0 23.1-28.0 28.1-33.0 > 33.1
30-39
19.0
19.1-24.0 24.1-29.0 29.1-34.0 > 34.1
40-49
20.0
20.1-25.0 25.1-30.0 30.1-35.0 > 35.1
≥ 50
21.0
21.1-26.0 26.1-31.0 31.1-36.0 > 36.1
WS 100
Over-
Normal
weight
Obese
Data in %
Men
Excellent
Good
Age
≤ 19
12.0
12.1-17.0 17.1-22.0 22.1-27.0 > 27.1
20-29
13.0
13.1-18.0 18.1-23.0 23.1-28.0 > 28.1
30-39
14.0
14.1-19.0 19.1-24.0 24.1-29.0 > 29.1
40-49
15.0
15.1-20.0 20.1-25.0 25.1-30.0 > 30.1
≥ 50
16.0
16.1-21.0 21.1-26.0 26.1-31.0 > 31.1
Water percentage
Body water % is an important indication of the overall «well
being» of a human being as water is the single most important
component of body weight and represents more than half (about
60 %) of the total weight.
Research shows that 57 % body water is optimum, but this
depends on the individual and normally there is no problem if the
reading is 10 % higher or lower.
The body water % is greater in childhood (at birth it varies from
70 % to 77 %) and it decreases with age (old people might have a
body water of 45 % to 55 %). Women (usually having more
adipose tissue than men), have a water ratio of about 55-58 %
while men have about 60-62 % of it.
With the increase of fat deposits, obese people also have a lower
body water % than lean people. In general, body water % is an
overall composite number. Below 40 % would normally be seen as
too low, and above 70 % as too high. Human beings excrete a
given quantity of water every day. This, however, must be regu-
larly replaced, a water loss of about 10 % of the body weight, may
put our health condition at risk.
So giving the body water % as a reading on the body fat scale
gives an indication to the user if there are possible problems, in
which case they would probably wish to consult their doctor.
Body weight variations that take place in a few hours are
completely normal and are due to water retention, since the extra-
cellular water (which includes interstitial fluid, plasma, lymph and
transcellular fluid) is the only compartment subject to such rapid
variations.
2. Suggestions for Use
• Place the scale on a flat, hard surface. Soft, uneven flooring
(e.g. rugs, carpets, linoleum) can cause the scale to give uneven
reading of your weight.
• Step onto the scale with your feet parallel and weight equally
distributed.
• Stand still while the scale measures your weight.
• It is important to weigh yourself with dry, bare feet, correctly
positioned on the electrodes. Moreover, for the scale to work
properly, avoid your legs touching.
• The scale is safe to use as a simple scale by everyone being
powered by a single 3 volt lithium battery. However, the following
people should not perform a body fat or body water measurement:
− pregnant women
− people on cardiovascular medication
− those fitted with a pace-maker or other forms of electronic,
medical equipment
− those with a temperature
− children under the age of 10
− those in dialysis, with oedemas on their legs, people with
dimorphism or suffering from osteoporosis
Over-
Normal
weight
Obese
Data in %
3
EN