Changes

* The trunk area is broken down into Android and Gynoid areas; Android obesity is the "apple" shape with fat is in the trunk and Gynoid obesity is the "pear" shape with increased fat in the hip and thigh areas. Fat deposition in the android region is associated with increased risk of cardiovascular disease, hypertension, hyperlipidemia, [[Insulin Resistance|insulin resistance]], and type-2 diabetes, while Gynoid fat deposition is associated with decreased risk of metabolic and cardiovascular diseases<ref name="Folsom-2000"/><ref name="Kissebah-1994"/>. * Because a DEXA scan gives details of lean tissue for each arm and each leg, it can give an idea of [[Muscle|muscle ]] imbalance.

While DEXA is the best practical method of determining body composition, its accuracy is not perfect. The best methods we have for determining the body composition of a living human are called "four component models" (4CM) which divide the body into water, [[Protein|protein]], mineral, and fat using radioactive isotopes to determine total body water and total body [[Potassium|potassium]]<ref name="Fuller-1992"/><ref name="Heymsfield-1990"/>. These methods are impractical, even in most clinical settings, but they can be used to evaluate DEXA and other techniques. A study of 152 people showed that DEXA corresponds well with the 4CM, but not perfectly<ref name="Van Der Ploeg-2003"/>. The graph below shows that DEXA tends to underestimate the body fat of leaner individuals. For DEXA values of 10, 20, and 30% body fat the 4CM showed 13.0, 21.6, and 30.3%, respectively. Overall, the DEXA scan had errors of up to −2.6 to 7.3% body fat, but the average error was only 1.6% (+/-0.8%).