Validation of Sarcopenic Obesity Screening Tools: A Cross-Sectional Analysis Based on ESPEN and EASO Criteria

<i>Background and Objectives</i>: Sarcopenic obesity, characterized by sarcopenia and obesity, is associated with adverse outcomes. The recent consensus from the European Society for Clinical Nutrition and Metabolism (ESPEN) and the European Association for the Study of Obesity (EASO) proposed a diagnostic algorithm (screening, diagnosis, and staging) for sarcopenic obesity. However, the effectiveness of recommended screening tools for sarcopenic obesity remains unclear. This study aimed to assess the performance of SARC-F questionnaire (Strength, walking Assistance, Rise, Climb, and Falls), calf circumference (CC), and SARC-CalF (SARC-F combined with CC), combined with obesity indicators, as screening tools for sarcopenic obesity. <i>Materials and Methods</i>: This cross-sectional study analyzed 2020 community-dwelling older adults from the Korean Frailty and Aging Cohort Study. Sarcopenic obesity was defined according to ESPEN and EASO criteria. Screening tools included SARC-F, CC, and SARC-CalF in combination with high body mass index (BMI; ≥25 kg/m²) or high waist circumference (WC; men, ≥90 cm; women, ≥85 cm). The diagnostic performance was evaluated using sensitivity, specificity, and predictive value. <i>Results</i>: SARC-F (≥4) with high BMI or WC demonstrated low sensitivity (men, 5.68%; women, 17.82%) but high specificity (men, 99.03%; women, 94.35%) and negative predictive value (NPV) (men, 91.68%; women, 91.09%). Lowering the SARC-F cutoff improved sensitivity but reduced specificity. CC combined with a high BMI or WC showed modest sensitivity (men, 34.09%; women, 34.65%) but moderate specificity (men, 59.48%; women, 59.91%). SARC-CalF (≥11) combined with high BMI or WC showed slightly higher sensitivity (men, 13.64%; women, 19.80%) but lower specificity (men, 95.04%; women, 86.93%) than SARC-F. <i>Conclusions</i>: SARC-F combined with obesity indicators may serve as a case-finding tool with high specificity and NPV, supporting its usefulness in ruling out sarcopenic obesity in the clinical setting. Meanwhile, CC was not an effective screening tool, and SARC-CalF did not substantially improve sensitivity or accuracy compared with SARC-F.