Article # 365. Lean Mass Vs. Fat Mass

Lean Mass Vs. Fat Mass

When you step on the scale, you will see a number. This number tells you what your body weighs, not what your body is composed of. Your body is made up of lean mass and fat mass. Your body needs to consist of more lean mass than fat mass for health purposes. However, both compositions have a role in the body.

Lean Mass

Lean mass is the part of your body that is not fat. Lean mass consists of bones, organs and, of course, muscle. Women should have at least 75 percent lean mass to be considered in the healthy range. Men should consist of at least 80 percent lean mass.

Fat Mass

Fat mass is the portion of your body consisting of fat, both essential and storage fat. Your body requires some fat for function, and this is called essential fat. In men, essential fat should make up 3 percent of the body's composition. Women require about 12 percent body fat for healthy function. Once your body has its essential fat requirements, any calories consumed in excess of what is required for metabolism will be stored as fat, unless used to build muscle (which requires exercise). Stored fat can then be used for energy, and if the body has no stored fat it will break down muscle for energy, which should be avoided.

Function of Fat Mass

Fat mass does have a function in the body. One function of fat is for proper hormone production. Females require more essential fat than males, and if a woman's level of essential fat falls too low, her body will stop menstruating due to improper hormone production. Fat is also necessary for nervous system functions, protection of organs and insulation.

Function of Lean Mass

Lean mass has many functions in the body. You probably think of muscle when you hear the term "lean mass," but you should consider the functions of other components of lean mass as well. Bones support the body and provide protection to organs. Organs also make up lean mass, and each organ has its own important function. The muscles function in multiple ways. Possibly most important, muscles allow you to move your joints and, therefore, your body. Muscles in your back and core help you stand up straight. Additionally, muscles protect your organs by providing cushioning and assist in regulating body temperature.

Considerations

Low fat mass and high lean mass are important for your health. Ideal body fat range for women is 16 to 25 percent and 12 to 18 percent for men. Having a higher fat mass increases your risk for developing serious health conditions such as diabetes, cardiovascular disease and cancers. To increase your lean mass and decrease your fat mass, a combination of proper diet and exercise, including aerobic work and resistance training, is required.