Backgrounds: Obesity is an established risk factor for erosive esophagitis. Yet, the associations of sarcopenia and obesity with erosive esophagitis remain unclear. We studied the associations of obesity, sarcopenia, and sarcopenic obesity with the risk of erosive esophagitis in a large number of asymptomatic men and women. Materials and Methods: We conducted a cross-sectional study of 32,762 asymptomatic adults undergoing routine health checkups including screening endoscopy, between August 2006 and December 2011. Sarcopenia was defined as an appendicular skeletal muscle mass (ASM) /body weight value beyond two standard deviations below the mean for healthy young adults. The ASM was estimated using bioelectrical impedance analysis. Results: Participants were categorized into four groups according to their obesity and sarcopenic status: normal, obese, sarcopenic, and sarcopenic obese. In a multivariable model adjusted for age, sex, smoking status, alcohol intake, regular exercise, and metabolic variables, the risk of erosive esophagitis was higher in obese [adjusted odds ratio(aOR), 1.38; 95% confidence interval (CI), 1.26-1.52], sarcopenic (aOR, 2.20; 95% CI, 1.48-3.29), and sarcopenic obese participants (aOR, 1.68; 95% CI, 1.39-2.03) than in normal participants. Comparing sarcopenic and sarcopenic obese participants to obese participants, the ORs for erosive esophagitis were 1.59 (95% CI, 1.06-2.38) and 1.22 (95% CI, 1.02-1.47), respectively. In dose-response analyses, increasing sarcopenia severity showed a positive and graded relationship with overall, LAB or higher grade, and LA-C erosive esophagitis. Conclusions: Our findings suggest that sarcopenia, regardless of obesity status, is strongly and progressively associated with the risk of erosive esophagitis. IntroductIon Gastroesophageal reflux disease is a widespread gastrointestinal disorder that frequently occurs in primary care settings, imposing considerable burdens on global health and economics [1]. Disease prevalence is 18.1-27.8% in North America, 8.8-25.9% in Europe, and 2.5-7.8% in East Asia, with rising rates worldwide [2]. Obesity is considered a significant contributing factor for a spectrum of reflux-related esophageal disorders ranging from