ABSTRACT
Typically, methods of determining body composition are based on the model which divides the body into two chemically distinct compartments: fat and fat free. The fat free compartment is further divided into three chemical groups: water, pro tein, and bone minerals. Additional methods for assessing body composition in clude: a) assessment o f total body water using isotopes of hydrogen, deuterium and tritium, b) estimation o f lean body mass from total body potassium or urinary crea tinine excretion, and c) assessment o f human body composition by densitometry and anthropometry. More recent methods, however, include measuring the multielemental composition o f the human body via neutron activation analysis; deter mining total body skeletal muscle mass with total plasma creatinine and endog enous urinary 3-methylhistidine excretion; and determining fat free mass by electrical conductance techniques. Although, more specific, some of these methods require complex laboratory equipment and do not provide accurate estimates o f body fat in an individual.1 Various radiologic examinations are now used to assess body compo sition, in the attempt to objectively determine the metabolic and nutritional status in patients requiring nutritional support. These methods of estimating body com position will be the focus of this chapter.
