## 4 Discussion  
In our study, we compared results from ADP and anthropometry, which were utilized as reference techniques to compare variables estimated from BIA, and found low clinical agreement between them. The results of body fat measurements in young adults from ADP differ significantly from those of BIA (InBody 770). InBody 770 showed underestimation and did not reveal acceptable agreement with BOD POD measures of %BF, especially in men (%FM BIA results lower by 1.237%). This has further implications for the assessment of metabolic health when using FM or FFM data for further classification or calculations. A low clinical agreement, with the tendency for overestimation by InBody 770, was also observed for WC, as well as for WHR, especially in females (WC BIA results higher by 3.537). These discrepancies generate differences in the classification of participants with or without central obesity, which may result in an incorrect assessment of the risk of cardiometabolic diseases. In line with previous findings, BIA %BF did not agree with ADP [11, 12, 13]. Opposite results were observed in the study by [PERSON] et al. [13], where ADP results were 3.1% lower than those obtained from BIA. It should be emphasized that different statistical methods and the interpretation of obtained data in assessing agreement, as employed by various authors, can lead to contradictory conclusions. Applying different criteria for the estimated \begin{table}
\begin{tabular}{c c c c} \hline \hline \multirow{2}{*}{**WC**} & \multicolumn{3}{c}{**VFA (BIA)**} \\  & **Total** & **Males** & **Females** \\ \hline BIA & 0.683 & 0.906 & 0.881 \\ Manual & 0.324 & 0.632 & 0.597 \\ \hline WC, Waist circumference; VFA, Visceral fat area. & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 10: Pearson correlation coefficient value (r) for VFA and WC measurements or estimations. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Central Obesity Risk**} & \multicolumn{2}{c}{**Total**} & **Males** & **Females** & \multirow{2}{*}{_p_**-Value**} \\  & **n = 203 (\%)** & **n = 76 (\%)** & **n = 127 (\%)** & \\ \hline Abnormal WC\({}_{\text{manual}}\)— & 46 (23) & 16 (21) & 30 (24) & ns \\ Abnormal WC\({}_{\text{BIA}}\)— & 62 (30) & 15 (20) & 47 (37) & 0.010 \\ \(p\)-Value & \textless{}0.001 & \textless{}0.001 & \textless{}0.001 & - \\ \hline Abnormal WHR\({}_{\text{manual}}\)— & 35 (17) & 23 (30) & 12 (9) & \textless{}0.001 \\ Abnormal WHR\({}_{\text{BIA}}\)— & 71 (35) & 18 (24) & 53 (42) & 0.009 \\ \(p\)-Value & \textless{}0.001 & \textless{}0.001 & \textless{}0.001 & - \\ \hline Abnormal WHR\({}_{\text{manual}}\)— & 41 (20) & 23 (30) & 18 (14) & 0.006 \\ Abnormal WHR\({}_{\text{BIA}}\)— & 43 (21) & 21 (28) & 22 (17) & ns \\ \(p\)-Value & \textless{}0.001 & \textless{}0.001 & \textless{}0.001 & - \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Percentages of participants (%) with central obesity (abnormal WC), abnormal WHR, and WHtR estimated by BIA and measured manually. measurement errors or the Bland-Altman index may result in conflicting findings regarding the interchangeability of methods used to estimate body composition. Therefore, in our study, we additionally employed the CCC and OLP regression to verify the validity of our conclusions. Adopting a Bland-Altman index threshold of 15% makes it easier to achieve agreement between the tested methods; however, for our values, remaining at a 5% threshold appears more appropriate. Differences in %BF exceeding 1% (in men) lead to incorrect classification of patients into groups with or without obesity. Similarly, for WC (or WHR), differences reaching 2 cm (in the total group) or 3.5 cm (in females) are significant enough to preclude considering the BIA method interchangeable with the manual method. These findings underline the importance of considering clinical concordance when evaluating the interchangeability of body composition assessment methods, as even minor discrepancies may have significant implications for clinical decision-making and patient classification.