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Body Composition And Body Fat Percent

 By Jennifer R. Scott | Reviewed by Richard N. Fogoros, MD
Updated November 22, 2017
Body composition is the proportion of fat and fat-free mass in your body. A healthy body composition is one that includes a lower percentage of body fat and a higher percentage of fat-free mass, which includes muscle, bones, and organs.

Body composition is measured to assess your health and fitness level. Often, you will have body composition measured at the start of a weight loss or fitness program and checked periodically to monitor your progress.

What Is Body Composition?

Your body is composed of two types of mass: body fat and fat-free mass.

Body fat can be found in muscle tissue, under the skin (subcutaneous fat), or around organs (visceral fat). Some fat is necessary for overall health. It is called essential fat and it helps protect internal organs, stores fuel for energy, and regulates important body hormones. But you may also have excess storage of fat and non-essential body fat.

Fat-free mass includes bone, water, muscle, organs, and tissues. It may also be called lean tissue. These tissues are metabolically active, burning calories for energy, while body fat is not.

Body fat percent is a measurement of body composition telling how much of the weight of your body is fat. The percentage of your body that is not fat is fat-free mass. There are normal ranges for body fat, which differ for men and women.

Weighing yourself on a regular bathroom scale does not truly assess your body composition because a regular scale cannot tell how much of your total weight is comprised of water, fat, or muscle.


American Academy of Orthopaedic Surgeons. Female Athlete Triad: Problems Caused by Extreme Exercise and Dieting. 


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