Validity of a Three-Dimensional Body Scanner: Comparison Against a 4-Compartment Model and Dual Energy X-Ray Absorptiometry
Three-dimensional (3D) body scanner technology for body composition assessment is expanding. The aim of this study was to assess the validity of a 3D body scanner. 194 participants (43% male; Age: 23.52±5.47 yrs; BMI: 23.98±3.24 kg·m-2) were measured using 3D scanner and a 4-compartment (4C) model utilizing DXA, air displacement plethysmography, and bioelectrical impedance spectroscopy. Dependent t-tests, validity statistics including total error (TE), standard error of the estimate (SEE), constant error, and Bland-Altman analyses were utilized. Compared to 4C, 3D scanner FM [mean difference (MD; 3D- 4C): 2.66 kg±3.32 kg] and %BF (MD: 4.13%±5.36%) were significantly (p<0.001) over-predicted; FFM was significantly underpredicted (MD: -3.15 kg±4.75 kg; p<0.001). 3D demonstrated poor validity indicated by TE (%BF: 5.61%; FM: 4.50 kg; FFM: 5.69 kg). In contrast, there were no significant differences between 3D and DXA measures; 3D scanner demonstrated acceptable measurement for %BF (TE: 4.25%), FM (TE: 2.92 kg), and LM (TE: 3.86 kg). Compared to the 4C criterion, high TE values indicated 3D estimates were not valid. In contrast, 3D estimates produced acceptable measurement agreement when compared to DXA; an average overestimation of %BF by 5.31% (vs. 4C) and 4.20% (vs. DXA) may be expected. Novelty: • 3D body composition estimates are not valid compared to the 4-compartment criterion model. • 3D estimates appeared to be more valid in females, compared to males. • When compared to DXA, 3D estimates were acceptable.