AbstractBackground and AimThis study aimed to evaluate the impact of physical activity (PA) on the course of hepatic steatosis (HS) in adults.MethodsHepatic steatosis status (ultrasonography) and PA levels were evaluated in 5860 subjects at baseline and after approximately 2.5 years (range: 19–50 months). At follow up, possible exposures to different PA levels were those who remained inactive, became inactive, became active, and remained active. After follow up, subjects were then classified according to the four possible states (outcomes): “remained without HS,” “developed HS” (subjects without HS at baseline), “remained with HS,” or “reverted HS.”ResultsAfter multivariate adjustments, individuals without HS that became or remained physically active were less likely to develop HS compared with those who remained physically inactive (odds ratio = 0.75, P = 0.04 and 0.75, P = 0.03, respectively). Among those with HS at baseline, becoming and remaining physically active beneficially improved the HS status (odds ratio = 0.64, P = 0.01 and 0.66, P = 0.01, respectively). However, the significance was lost when adjusted for changes in body mass index.ConclusionHigher levels of PA were associated with prevention and treatment of HS, with evidence of effect mediation by changes in body mass index.