Three-dimensional optical (3DO) imaging systems that rapidly, safely, and accurately provide body shape and composition information are increasingly available in industry, research, and clinical settings. Recently, relatively low cost and space efficient 3DO systems were introduced to the consumer market for home use. This study critically evaluated the first of these devices, the Naked Body Scanner (NBS), against reference methods.
Circumferences at six standardized anatomic sites were measured with a flexible tape in a sample of ninety participants ranging in age (5-74 years), ethnicity, and adiposity. Regression analysis and Bland-Altman plots compared these reference estimates and dual-energy X-ray absorptiometry (DXA) percent fat results to those calculated by the NBS. Method precision was analyzed from duplicate anthropometric and 3DO measurements in a subgroup of fifty-one participants.
The NBS exhibited greater variation in test-retest reliability (CV, 0.3±0.3% to 1.3±2.5%) between the six measured anatomical locations when compared to their manually measured counterparts (0.1±0.1% to 0.2±0.3%). All six device-derived circumferences correlated with flexible tape measurements (R2s, 0.84–0.97; p <0.0001); bias was apparent in two anatomic sites while mean differences were present in five. The NBS’s percent fat estimates also correlated with DXA scan results (R2=0.73, p < 0.0001); bias estimates were non-significant.
Overall, the NBS provides a quality health and wellness assessment complete with accurate somatic measurements and body composition estimates. The scanner’s precision and accuracy with respect to reference methods parallels previous evaluations of larger, more expensive 3DO devices.