Abstract
Introduction: Assessing the nutritional and morphofunctional status of patients with obesity is essential for optimizing their management. Nutritional ultrasound (NU) is a non-invasive, portable technique that offers insights into muscle and adipose tissue status. Combining NU with bioelectrical impedance analysis (BIA) and handgrip strength (HGS) may improve the assessment of body composition and muscle functionality. This study aimed to evaluate the usefulness of NU as a primary tool for morphofunctional assessment in patients with obesity, while comparing and complementing it with BIA and HGS. Results: In a cohort of 178 patients with obesity, we analyzed body composition using NU, BIA and HGS, which are widely accepted methods for assessing body composition and muscle strength, respectively. Significant correlations were found between NU-measured quadriceps rectus femoris cross-sectional area (CSA) and BIA-derived fat-free mass markers, such as body cell mass (r = 0.638, P < 0.001) and appendicular skeletal muscle mass (r = 0.591, P < 0.001). Additionally, leg subcutaneous adipose tissue (L-SAT) measured by NU was highly correlated with BIA-measured fat mass (r = 0.656, P < 0.001). Linear regression analyses further confirmed the importance of RF-CSA as a strong predictor of body cell mass (BCM), along with HGS and BMI, explaining 78.2% of the variability in BCM (R² = 0.782, AIC = 672). Conclusion: These findings suggest that NU, combined with BIA and HGS, provides a comprehensive, practical tool for assessing body composition and muscle function in obesity management, with the potential for routine application in clinical settings.