G
B
9
G
B
8
Body Fat - What does it mean?
The human body is made up of, amongst other things, a percentage of fat.This is vital for a healthy,
functioning body - it cushions joints and protects vital organs, helps regulate body temperature, stores
vitamins and helps the body sustain itself when food is scarce. However, too much body fat or indeed
too little body fat can be damaging to your health. It is difficult to gauge how much body fat we have in
our bodies simply by looking at ourselves in the mirror.
This is why it is important to measure and monitor your body fat percentage. Body fat percentage
gives you a better measure of fitness than weight alone – the composition of your weight loss could
mean you are losing muscle mass rather than fat - you could still have a high percentage of fat even
when a scale indicates ‘normal weight’.
Body Water - Why measure it?
Body water is the single most important component of body weight. It represents over half of your
total weight and almost two thirds of your lean body mass (predominantly muscle).
Water performs a number of important roles in the body:
All the cells in the body, whether in the skin, glands, muscles, brain or anywhere else, can only function
properly if they have enough water.Water also plays a vital part in regulating the body’s temperature
balance, particularly through perspiration.
The combination of your weight and fat measurement could appear to be ‘normal’ but your body
hydration level could be insufficient for healthy living.
How can knowing your body fat and water percentages help?
It can serve as a guide to whether you need to adjust your diet, fitness program or fluid intake to help
achieve a healthy balance. Refer to tables (See Fig 1 and Fig 2).
UNDERSTANDING YOUR RESULTS
AGE
20-29 30-39 40-49 50-59
60+
Low
<13
<14
<16
<17
<18
Optimal
14-20 15-21 17-23 18-24 19-25
Moderate
21-23 22-24 24-26 25-27 26-28
High
>23
>24
>26
>27
>28
AGE
20-29 30-39 40-49 50-59
60+
Low
<19
<20
<21
<22
<23
Optimal
20-28 21-29 22-30 23-31 24-32
Moderate
29-31 30-32 31-33 32-33 33-35
High
>31
>32
>33
>34
>35
Body Fat % Ranges for Men**
Body Fat % Ranges for Women**
Fig. 1
Body Water Chart***
BF % RANGE
OPTIMAL TBW % RANGE
Men
4 to 14%
70 to 63%
15 to 21%
63 to 57%
22 to 24%
57 to 55%
25 and over
55 to 37%
Women
4 to 20%
70 to 58%
21 to 29%
58 to 52%
30 to 32%
52 to 49%
33 and over
49 to 37%
Fig. 2
** Source: University of Illinois
Department of Food Science and
Human Nutrition.
Body Fat Percentage Calculator.
www.ag.uiuc.edu/~food-lab/ai/bfc.html
*** Source: Derived from Wang &
Deurenberg: “Hydration of fat-free
body mass”. American Journal Clin
Nutr 1999, 69 833-841.
Body water measurement results are influenced by the proportion of body fat and muscle. If the
proportion of body fat is high, or the proportion of muscle is low then the body water results will
tend to be low.
It is important to remember that measurements such as body weight, body fat and body water are
tools for you to use as part of your healthy lifestyle. As short term fluctuations are normal, we suggest
you chart your progress over time, rather than focus on a single days reading.
Basal Metabolic Rate (BMR) - What does it mean?
Your Basal Metabolic Rate (BMR) is an estimation of the energy (measured in calories) expended by
the body, at rest, to maintain normal body functions.This continual work makes up about 60-70% of
the calories the body uses, and includes the beating of your heart, respiration, and the maintenance of
body temperature.Your BMR is influenced by a number of factors, including age, weight, height, gender,
dieting and exercise habits.
Why Should I Know My Muscle Mass?
According to the American College of Sports Medicine (ASCM), lean muscle mass may decrease by
nearly 50 percent between the ages of 20 and 90. If you don’t do anything to replace that loss you’re
losing muscle and increasing fat. It is also important to know your muscle mass % during weight
reduction. At rest, the body burns approximately 110 additional calories for each kilo of muscle gained.
Some advantages of gaining muscle mass include:
•
Reversing the decline in strength, bone density and muscle mass that accompanies age.
•
Maintenance of flexible joints.
•
Guide weight reduction when combined with a healthy diet.
