Submitted to: Mediterranean Journal of Nutrition and Metabolism
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/3/2009
Publication Date: 4/1/2009
Citation: Lukaski, H.C. 2009. Evaluation of Body Composition: Why and How?. Mediterranean Journal of Nutrition and Metabolism. 2:1-10.
Interpretive Summary: Assessment of human body composition is fundamental in evaluating the nutritional status of an individual or a group of people. Body composition can be described as body fat mass or percent of body mass as fat, fat-free mass, water, and bone. No single method allows the determination of all of these components. Dual x-ray absorptiometry estimates fat, fat-free and bone. In contrast, devices that measure body volume and body water allow estimation of the mass of the fat-free body (muscle, organs, and bone) based on assumptions of its chemical composition. Reliance on absolute measurements of fat and water is problematic because standards for normal values are lacking. In contrast, individual values of bone mass and quality (density) can be compared to standards for prediction of risk of osteoporosis. Also, a new application of electrical conductivity enables assessment of fluid balance status.Opportunities are available to expand the use of body composition assessment technology to link nutritional status with risk for some chronic diseases and to monitor interventions. This information will be useful to dietetic and public health professionals who seek to evaluate body composition in clinical nutrition and epidemiological studies.
Technical Abstract: Evaluation of human body composition in vivo remains a critical component in the assessment of nutritional status of an individual.Whereas traditional measurements of standing height and body weight provide information on body mass index and, hence, the risk of some chronic diseases, advanced technologies, such as dual x-ray absorptiometry, air displacement plethysmography, and various forms of bioelectrical impedance analysis, enable the determination of soft tissue composition (fat and lean) as well as bone. This review summarizes the physical bases of these methods and critically evaluates their accuracy in observational and interventional studies. It also discusses a new approach, bioelectrical impedance vector analysis, which assesses the hydration status of an individual, and includes pertinent examples of its novel applications in clinical nutrition.