The Impact of Feet Callosities,Arm Posture,and Usage of Electrolyte Wipes on Body Composition by Bioelectrical Impedance Analysis in Morbidly Obese Adults

ObjectiveThis study evaluated the impact of feet callosities, arm posture, and use of electrolyte wipes on body composition measurements by bioelectrical impedance analysis (BIA) in morbidly obese adults.Methods36 morbidly obese patients (13 males, aged 28–70 years, BMI 41.6 ± 4.3 kg/m²) with moderate/severe feet callosities participated in this study. Body composition (percent body fat (%BF)) was measured while fasting using multi-frequency BIA (InBody 720®), before and after removal of callosities, with and without InBody® electrolyte wipes and custom-built auxiliary pads (to assess arm posture impact). Results from BIA were compared to air displacement plethysmography (ADP, BodPod®).ResultsMedian %BF was significantly higher with auxiliary pads than without (50.1 (interquartile range 8.2) vs. 49.3 (interquartile range 9.1); p < 0.001), while no differences were found with callosity removal (49.3 (interquartile range 9.1) vs. 50.0 (interquartile range 7.9); NS) or use of wipes (49.6 (interquartile range 8.5) vs. 49.3 (interquartile range 9.1); NS). No differences in %BF were found between BIA and ADP (49.1 (IQR: 8.9) vs. 49.3 (IQR: 9.1); NS).ConclusionArm posture has a significant impact on %BF assessed by BIA, contrary to the presence of feet callosities and use of electrolyte wipes. Arm posture standardization during BIA for body composition assessment is, therefore, recommended.Key Words: Bioelectrical impedance, Body composition, Morbid obesity, Callosities, Fat mass, Standardization