What is Body Composition

In simple terms, the body is made of 3 tissue types – lean dense muscle mass, body fat, and bone. Even though two people can have similar weight they can have drastically different body shape and health status because of different proportions of these tissue types. Body composition analysis measures the amount of lean dense tissue and body fat to determine one’s overall health status.

What Body Composition is Important

Because the 3 types of body tissues have different metabolic activity, the relative amounts of each have an impact on one’s health. In general, a greater percentage of lean muscle mass is associated with better health.

What is a DEXA scan?

Traditionally, body composition has been measured using calipers on skin folds or body weight in water. These techniques provide only a gross approximation of total body composition. DEXA uses a very low dose dual X-Ray full body scan that measures the actual amount of the three tissue types – bone, muscle and fat. By measuring the different tissue densities DEXA can provide total fat, mineral and lean tissue mass in 6 symmetrical regions of the body. Bone mineral content is also provided for 10 regions of the body. The results are very accurate and specific for you.

What parts of the body are measured?

The scan the entire body and provides the total mass of all 3 tissues types in 6 regions of the body – (Right/Left arm, Trunk, R/L Leg, Head). In addition, bone mineral content (BMC) is provided in 10 regions – (R/L Arm, R/L Ribs, Thoracic/Lumbar Spine, Pelvis, R/L Leg, Head).Is it Safe?Yes. The procedure requires the person to lay supine for 15 minutes while the DEXA system scans the body. The total radiation exposure during the procedure is negligible at ~0.04  mrem. For reference, 1 mrem equals normal background radiation in one day.


Who are Body Composition scans appropriate for?

Even though body weight may stay the same, body composition can change for a variety of reasons. Whether you are in a treatment program for chronic disease, undertaking dietary and lifestyle changes to improve your body shape, an athlete trying to achieve peak performance, or are just trying to maintain healthy lean body mass as you age, the ability to monitor changes in body composition offers a valuable tool to modify your plan over time.

How should I prepare for the DEXA/Body Composition?

A DEXA scan is a quick and painless exam of your low back and hip bones. A Body Composition analysis is a similar exam, but requires a quick scan of your entire body. Both exams use an extremely low dose x-ray. Each exam takes approximately 15 minutes.

Please read the following to prepare yourself for a Body Composition;

  • Fasting (same day)
  • No alcohol 24 hours prior
  • No intense exercising 24 hours prior
  • Empty bladder
  • Minimal clothing
  • Remove body jewelry or metal such as zippers, buttons, metal bra claps, etc.
  • Preferred clothing would be workout gear