Medicine (USARIEM) posed six questions for the CMNR to aid in its evaluation of the techniques reviewed and its provision of guidance to MND concerning their applications to the military.
In this chapter, the CMNR provides its answers to the questions posed by the Army, draws its conclusions on each of the six technologies reviewed, and makes its recommendations. The responses, conclusions, and recommendations were developed in discussion and prepared in executive session of the CMNR.
This section is organized according to the six categories of technologies, with all of the Army's questions being answered under each technology.
1. Will the technologies be a significant improvement over current technologies?
Anthropometric equations currently used by the military could be further refined with additional computer modeling, particularly with regard to their application to all ethnic groups. Computerized axial tomography (CAT) scanning, magnetic resonance imaging (MRI), and dual-energy x-ray absorptiometry (DXA) measurements can and have markedly improved compositional methodology in the clinic. These techniques could be used by the military to improve the accuracy and reliability of derived equations that use anthropometric measures to predict body fat content.
Single-frequency bioelectrical impedance analysis (BIA) is not a reliable measure of body composition, but the methodology may be helpful in answering specific questions concerning hydration status. Multiple-frequency bioelectrical impedance spectroscopy may hold promise for compositional measurement in the future.
2. How likely are the technologies to mature sufficient for practical use?
Body composition (BC) methods are already quite mature, although multiple-frequency BIA requires some specific developmental work. The multifrequency method of BIA involves a simple and low-cost measurement system, but it is not sufficiently developed to provide accurate and reproducible estimates of changes in body composition. Its relative simplicity and low cost suggest that further development may be useful to see if current shortcomings can be overcome.
At present, CAT scanning, MRI, and DXA provide reliable measures of composition but are expensive. CAT requires exposure to x rays, although some