A successful Long-Term Weight Loss (LTWL) is associated with a more favorable metabolic disease risk profile. However, evidence is limited on the association of LTWL with obesity-related complications defined by Edmonton obesity staging system (EOSS). Hence, our study aims to assess the association between LTWL thresholds and obesity-related complications defined by EOSS among the adult US population. We used data from the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2018. Adults 18 years or older with overweight/obesity and long-term weight loss were included in the analysis. The association between long-term weight loss and obesity-related complications defined by EOSS was investigated. A multivariable logistic regression model was employed by adjusting for potential covariates. A total of 22,223 adults were included in the analysis. Overall, 61.8% of participants had long-term weight loss of <5%, and 4.8% of participants had successful long-term weight loss of 20% or greater. The highest long-term weight loss threshold ( ≥ 20%) had the lowest odds of EOSS stage ≥ 2 (odds ratio [OR] = 0.60; 95% CI:0.50, 0.72; p < 0.001). The lowest LTWL threshold (5-9.9%) was relatively associated with lower odds for EOSS stage ≥ 2 [OR = 0.69 95% CI: 0.61, 0.78, p < 0.001]. The LTWL categories were significantly associated with lower odds of EOSS stage ≥ 2 compared to EOSS 0 or 1. Future longitudinal research assessing the association between LTWL and EOSS components is recommended.