Bioelectrical impedance analysis <i>v</i> . dual-energy X-ray absorptiometry for assessing segmental body composition in healthy adults

This study aimed to evaluate the agreement between three body composition devices and dual-energy X-ray absorptiometry (DXA) in assessing segmental body composition among healthy Iranian adults. This comparative study recruited 62 healthy adults (33 men and 29 women) from Tehran, Iran, using a convenience sampling approach. Socio-demographic data were collected, and segmental body composition was assessed using several devices, including the InBody 770, Anea bioelectrical impedance analysis (BIA), Tanita BC-418 and DXA. Agreement between DXA and the BIA devices was evaluated using Lin's concordance correlation coefficient (CCC). Additionally, Bland-Altman plots and mean percentage error were applied to assess the consistency between the two methods. The Anea, InBody 770 and Tanita BC-418 devices showed strong correlation with DXA for all segmental measurements (<i>r</i> ≥ 0·74, <i>P</i> < 0·05). Moderate agreement (CCC: 0·90 ≤ CCC < 0·95) with the DXA method was found for some segments using the Anea (trunk fat mass, arms fat-free mass, legs fat-free mass and trunk fat-free mass) and the InBody 770 (trunk lean body mass and trunk fat mass) devices. The estimation of legs fat mass was the least accurate across all BIA devices. Furthermore, subgroup analyses showed that the BIA devices provided more precise results in men and in individuals with a BMI < 25·00 kg/m². The Anea BIA and InBody 770 devices show relatively acceptable validity for segmental body composition assessment. More research is needed to confirm these findings.