A multi-method comparison of body volume and body fat in healthy adults: source of caution for interchangeability of techniques

BACKGROUND AND AIM: The interchangeability of different techniques for volume measurements makes it important to cross-calibrate volumes from different scanning systems against a gold standard Air Displacement Plethysmography (ADP), and identify possible causes of the differences. MATERIALS AND METHODS: A sample of 121 adults (78 males and 43 females, aged 18 – 44 y underwent body volume measurement via ADP (Bodpod system, Cosmed, Rome, Italy) and 3D scanning using portable scanner (Artec L, Artec Luxembourg) and fixed laser scanner (Hamamatsu BLS, Hamamatsu, Japan). Duplicate measurements were undertaken in 12 participants. RESULTS: Measurements were highly correlated between techniques for volume (R=0.989; 0.977 and 0.979; P<0.0001) and inter-technique errors for volumes and girths were <1% technical error of measurement. Bland and Altman analysis revealed volume measurements differed between Hamamatsu and both Artec and Bodpod (P<0.05), but were similar between Artec and Bodpod (P>0.05) and these patterns remained when volumes were converted into %fat. There were no significant differences between anthropometric and 3DS-extracted waist and hip girths for either scanner type (P>0.05). CONCLUSION: Despite their comparability for extracted waist and hip girth, the scanners are not interchangeable for volume and %fat estimation.