A Comparison between Neutron Activation and Dual Energy X-ray Absorptiometry for the Measurement of Body Fat

Neutron activation analysis is one of the most direct methods for assessing body composition in vivo because the technique does not inherently require calibration against another method. It is not, however, widely available. Recent developments in the alternative technique of dual-energy X-ray absorptiometry (DXA), offer the potential to measure the principal components of bone mineral, fat and fat-free tissue using a more readily available technology. Evaluation of the mineral compartment has been extensively researched, but the potential for fat tissue measurement has received less attention, especially in conditions departing from normal body composition. This study was designed, therefore, to compare measurements of fat by DXA with those obtained using the more established method of in vivo neutron activation analysis (IVNAA) in a group of predominantly obese female subjects having a wide range of body composition.