Total body weight has two components, lean weight and fat weight. Lean weight includes the muscles, bones, tendons, ligaments, and water in the body. Fat weight includes the fat stored in the fat cells and the organs of the body.
For good health, it is important to have a high proportion of lean weight compared to fat weight. Lean weight produces work and burns food kilojoules. Fat weight is excess baggage for the body and this can be a detriment to health.
The most accurate way to measure lean weight is to weigh a person underwater. This is done by scientists for research mainly on athletes. It is not practical for everyday use. Skinfold measurements using special calipers are more practical for estimating the fat and lean components of total body weight. Skinfold measurements are available at most fitness centres that have fitness instructors.
Some fitness centres provide circumference measurements of the arms, legs, and trunk to estimate lean and fat weight. These measurements are not sensitive to changes that take place in the lean and fat components of the body. For example, after being sedentary for several months, the fat component may decrease without any change taking place in the leg circumference. Skinfold measures would be more accurate in detecting the increase in leg fat in this example.
Bioelectric impedance is also used by some fitness centres to estimate the amount of fat and lean in the body. Because it measures resistance in the body, impedance is sensitive to the total water content, and the body fat calculation fluctuates with the changes in body water. Therefore, it is not as accurate or reliable as skinfold measures.
Some companies promote the use of infrared rays to estimate the thickness of the fat layer just under the skin. This technology has not been proven to be accurate or reliable. For the average male, lean weight is about 80 percent of the total body weight and fat weight is 20 percent. Females have about 75 percent lean and 25 percent fat weight proportions. The fat percentage for females is normally higher due to the breast tissue.
Male and female athletes have lower percentages of fat compared to average because they burn the fat kilojoules for energy and store less fat in the fat cells. Male athletes average less than 10 percent fat and female athletes average about 15 percent fat.
Obese people, on the other hand, have more than 30 percent fat weight. This can be a risk factor for various health problems and it is recommended that aerobic exercise and proper nutrition be used to help lower the fat content of the body toward the normal average.
Article #7510
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