Critical Appraisal of Data Acquisition in Body Composition: Evaluation of Methods, Techniques and Technologies on the Anatomical Tissue-System Level

Abstract

Human body composition (BC) could well be the only health-related discipline that allows both "simple indexes" e.g. the Body Mass Index, and “advanced technology" e.g. dual energy X-ray absorptiometry, to be used for the same purpose: the quantitative measurement of BC components for the prediction of health risk. Human BC probably is the most confusing health-related discipline also because of the mixture of apparent corresponding and analogue terminology. The major problems with quality control in BC are the large amount of different models and devices each with their own advantages and limitations, and their respective validation against other indirect data-acquisition methods or technologies. The validation of anthropometric techniques has generally been performed against twoor three-compartment models of BC such as hydrodensitometry or dual energy X-ray absorptiometry. These reference standards themselves are based on assumptions of a constant density, constant hydration and constant tissue distribution throughout the human body, without taking into account the biological variation of tissue composition. The quality control and validation of indirect in vivo measurements for BC against direct measurements is both scarce/almost un-edited and essential: it is known that there are wide variations in the indirect measurements currently used in practice, which makes any clinical decisions based on those measurements suspect. This chapter will give a critical appraisal of three frequently used data acquisition methods for measuring individual BC, in particular hydrodensitometry, body mass index and dual energy X-ray absorptiometry. In addition this chapter will provide a (renewed) critical appraisal of the most confusing terminology.