SYSTEMATIC ORGANIZATION OF BODY-COMPOSITION METHODOLOGY - AN OVERVIEWWITH EMPHASIS ON COMPONENT-BASED METHODS

The field of body-composition research currently lacks a systematic or ganization of methods used to quantitate components at the atomic, mol ecular, cellular, tissue-system, and whole-body levels of body composi tion. In this report we propose a classification system for body-compo sition methodology that proceeds in steps, beginning with division of methods into in vitro and in vivo categories, advances to organization by measurable quantity (property, component, or combined), and ends w ith grouping of methods by mathematical function (types I and II). Imp ortant characteristics of component-based methods are then developed, including a classification of component relationship types, the role o f ratios and proportions in type II component-based methods, and the b asis of simultaneous equations in multicomponent methods. This classif ication system, the first founded on a conceptual basis, explains simi larities and differences between. the many diverse methods, provides a framework for teaching body-composition methodology theories to stude nts, and suggests future research opportunities.