BackgroundOxidative Balance Score (OBS) is a tool for assessing the oxidative stress-related exposures of diet and lifestyle. The study aimed to investigate the association between OBS and low muscle mass.MethodsOverall, 6,307 individuals over the age of 18 were assessed using data from the 2011 to 2018 National Health and Nutrition Examination Survey (NHANES). Weighted logistic regression and models were used, together with adjusted models.ResultsThere was a negative relationship between OBS and low muscle mass [odds ratio (OR): 0.96, 95% confidence interval (CI): 0.94–0.97, p< 0.0001] using the first OBS level as reference. The values (all 95% CI) were 0.745 (0.527–1.054) for the second level, 0.650 (0.456–0.927) for the third level, and 0.326 (0.206–0.514) for the fourth level (P for trend