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ARS Home » Pacific West Area » Davis, California » Western Human Nutrition Research Center » Obesity and Metabolism Research » Research » Publications at this Location » Publication #195355
Title: THE HOW AND WHY OF BODY COMPOSITION ASSESSMENT IN ADULTS

Author
item CHUMLEA, WM - WRIGHT STATE UNIVERSITY
item REMSBERG, KAREN - OHIO ST., OSTEOPATHIC MED
item Van Loan, Marta

Submitted to: CRC Press
Publication Type: Book / Chapter
Publication Acceptance Date: 5/1/2007
Publication Date: 7/1/2007
Citation: Chumlea, W.C., Remsberg, K.E., Van Loan, M.D. The how and why of body composition assessment in adults. CRC Press, Hand Book of Nutrition and Food, 2nd Edition. 2007. 589-596.

Interpretive Summary: A variety of direct and indirect methods are available to quantify human body composition at the following levels: 1) the atomic level for the elements of carbon, calcium, potassium and hydrogen, 2) the molecular level for amounts of water, protein and fat, 3) the cellular level for extra-cellular fluid and the body cell mass and 4) the tissue level for amounts and distributions of adipose, skeletal and muscle tissues. This methodology is based upon assumptions regarding the concentrations of elements, water and electrolytes, the density of body tissues, biological inter-relationships between body components and body tissues, and their distributions among groups of normal weight adults. Detailed aspects of body composition methodology, its theories, general applications, equipment and analytical techniques are found in this reference text.

Technical Abstract: Body composition assessments quantify amounts of lean or fat-free mass (FFM) and fat mass (FM). Other reasons for a body composition assessment may include, but are not limited to the determination of 1) bone mineral content (BMC) and bone mineral density (BMD) to screen for and diagnosis osteoporosis, 2) total body water (TBW) and extra-cellular water (ECW) in adults with end-stage renal disease or other disorders affecting body fluids, or 3) monitoring changes in body composition during clinical treatment. Direct assessments like neutron activation and total body counting quantify chemical elements in the body from the atomic level up to the tissue level, while indirect methods estimate body composition from the molecular level through the tissue level via data collected from and validated against another method and a reference sample. Indirect methods view the body as a compartmental system consisting of TBW, ECW, BMC, FFM and FM. These compartments are quantified from models using the hydration level, density, chemical composition and BMC of FFM, the density of FM, and the reference samples used to validate them; they are not "gold standards" for in vivo body composition assessment. Specific details on these methods, assumptions and use can be found in this reference text.