Body composition measurements during wasting diseases.

Body wasting is a common feature of severe chronic diseases. Determination of body compartments is essential in the evaluation of patients with wasting diseases in order to optimize their nutritional support. The main methods described together with their advantages and disadvantages are anthropometric measurements, bioelectrical impedance analysis, dual-energy X-ray absorptiometry, total body water, total body potassium and in-vivo neutron activation analysis. The combination of dual-energy X-ray absorptiometry to measure bone and fat mass and bioelectrical impedance analysis to determine total body water and fat-free mass permits evaluation of body composition and periodic follow-up of body compartments in various pathologies. Total body potassium, total body water and in-vivo neutron activation analysis are research methods that elucidate the abnormal consequences of chronic pathologies on hydration status and body cell mass.