Why Is It Important to Monitor Your Total Body Water
(TBW%) Percentage?
Monitoring the level of body water can be a useful tool for one’s health maintenance.
Water is an essential component of the body and is one of the body’s overall health
indicators. Water makes up approximately 50-70% of the body’s weight and is present
proportionally more in lean tissue as compared to fat tissue.
For example:
• 73% of lean muscle tissue is water
• 80% of blood is water
• 25% of fat is water
• 22% of bone tissue is water
Additionally, water is also a medium for biochemical reactions that regulate body functions.
The estimated TBW% may vary according to your hydration level. For better accuracy,
avoid fluctuations in hydration level prior to taking a measurement.
The accuracy of the unit in estimating TBW% will also decrease with individuals suffering
from diseases or illnesses that tend to accumulate water in the body. Please remember
that the unit represents only a good approximation of your total body water.
The normal TBW% of an individual varies according to body fat percentage and gender.
The table below may be used as a guide:
†† Source: Derived from Wang & Deurenberg: “Hydration of fat-free body
mass”. American Journal Clin Nutr 1999; 69 833-841.
Why Should I Monitor My Skeletal 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 50 additional calories for each pound of muscle gained. Some
advantages of gaining muscle mass include:
• Reversing the decline in strength, bone mineral and muscle mass that accompanies age
• Maintenance of flexible joints
• Guide weight reduction when combined with a healthy diet
This body composition scanner tells you the total weight of skeletal muscle in your
body. The normal weight of skeletal muscle mass for men is approximately 40% of total
body weight. For women, normal muscle mass is approximately 30% of total body
weight (International Commission on Radiological Protection, 1975). To find your muscle
mass %, follow this formula:
Use the chart below to see if your muscle mass is low, normal or high.
* Muscle Mass (in pounds)
Total Body Weight
= Muscle Mass %
MUSCLE MASS % RANGES
† Source: HoMedics,
2006. Figures
based on the
following formula:
Weight of
individual’s
skeletal muscle
(in pounds)/total
body weight
(in pounds).
†
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