Body Composition
The previous two measurements that we talked about -BMI and waist circumference—are really good, easy, quick measures of health risk. But sometimes we want to know a little bit more about the tissues that make up your body. And so that's what we define as body composition. It's allowing you, when you measure body composition, it's allowing the researcher or the clinician to assess the percentage of fat versus the percentage of fat free tissue that someone has in their body.
And so fat is the first type of tissue. We have both essential and storage fats. The essential are the amount of fat that your body absolutely needs to do all of its proper functioning, and then storage fat is anything that you are essentially stockpiling on top of those essential fats.
The other type of tissues you would have in your body would be fat free tissue, and so when you do a body composition measurement usually you get a percentage fat and a percentage fat free tissue. The fat free includes many different things—muscles, bones, organ tissues, blood, and pretty much everything else except for the fat.