BackgroundObesity is a significant risk factor for the progression of non‐alcoholic fatty liver disease (NAFLD). However, a convenient and efficacious non‐invasive test for monitoring NAFLD progression in patients with obesity is currently lacking. This study aims to investigate the associations between CT‐based body composition and the progression of biopsy‐proven NAFLD in patients with obesity.MethodsLiver biopsy was conducted in patients with obesity, and the progression of NAFLD was evaluated by the NAFLD activity score (NAS). Body composition was assessed through abdominal computed tomography (CT) scans.ResultsA total of 602 patients with an average age of 31.65 (±9.33) years old were included, comprising 217 male patients and 385 female patients. The wall skeletal muscle index (SMI), total SMI, and visceral fat index (VFI) were positively correlated with NAS in both male and female patients. Multivariate regression analysis demonstrated significant associations between high liver steatosis and wall SMI (HR: 1.60, 95% CI: 1.12 to 2.30), total SMI (HR: 1.50, 95% CI: 1.02 to 2.08), VSI (HR: 2.16, 95% CI: 1.48 to 3.14), visceral fat to muscle ratio (HR: 1.51, 95% CI: 1.05 to 2.18), and visceral to subcutaneous fat ratio (HR: 1.51, 95% CI: 1.07 to 2.12). Non‐alcoholic steatohepatitis (NASH) was significantly associated with wall SMI (HR: 1.52, 95% CI: 1.06 to 2.19) and VSI (HR: 1.50, 95% CI: 1.03 to 2.17). Liver fibrosis ≥ F2 was significantly associated with psoas muscle index (HR: 0.64, 95% CI: 0.44 to 0.93) and psoas skeletal muscle density (HR: 0.61, 95% CI: 0.41 to 0.89).ConclusionsOur study suggested that certain CT‐based body composition indicators, notably high VFI, were significantly associated with the progression of NAFLD in patients with obesity. Great attentions and timely managements should be given to these patients with body composition characteristics associated with the risk of NAFLD progression.