Comparison of Bioelectrical Impedance Analysis and Computed Tomography on Body Composition Changes Including Visceral Fat After Bariatric Surgery in Asian Patients with Obesity

Purpose The accuracy of bioelectrical impedance analysis (BIA) in patients with obesity has been controversial. This study aimed to validate the use of BIA in detecting body composition changes, especially for visceral fat, before and after bariatric surgery using computed tomography (CT) as a reference method. Materials and Methods This retrospective study included Korean patients with a BMI of ≥ 35, or ≥ 30 with metabolic comorbidities. All patients underwent bariatric surgery, and underwent BIA and CT evaluation before and 6 months after the operation. The skeletal muscle index (SMI) and visceral fat index (VFI), variables corrected for height, were compared between BIA and CT. Results Forty-eight patients (18 men, 30 women) demonstrated a mean weight loss of 27.5 kg. Significant decreases in both VFI and SMI were observed in both BIA and CT (all p