Muscle Mass in the Body
Using the muscle mass index helps determine the percentage of muscles in the body. When assessing overall health, the focus is on the ratio of muscles to fat. It’s important to note that a pound of muscle weighs the same as a pound of fat, but muscles occupy less space and are more compact, while fat is larger in size and not compressed.
Calculating Muscle Mass
The muscle mass index can be calculated by:
Calculating Fat Mass
Fat mass can be determined by measuring body weight on a body fat scale, after which the muscle mass percentage can be found by subtracting the fat percentage from 100. For example, if the fat percentage is 25%, then the percentage of lean muscle mass in the body is 75% (100 – 25 = 75). Then, multiply the percentage of muscle mass by the total weight. For example, if the weight is 175 pounds (79.38 kilograms), it is multiplied by 0.75, resulting in a muscle mass of 131.25 pounds (59.42 kilograms).
X-ray Scans
Muscle mass percentage can also be determined through a dual-energy X-ray absorptiometry (DEXA) scan, which measures muscle mass, fat mass, and bone density. During the scan, the individual lies on a table for about 12 minutes while being exposed to safe radiation.
Total Body Mass
The body mass index (BMI) can be calculated by dividing total weight in kilograms by the square of height in meters, that is (total weight / height (in meters) x height (in meters)). For example, if a person weighs 99.97 kilograms and is 1.905 meters tall, their BMI would be: 99.97 / (1.905 x 1.905) = 27.5.
