Non-alcoholic steatosis (non-alcoholic fatty liver disease [NAFLD]), now considered a metabolic pathway to advanced liver disease, cirrhosis and hepatocellular carcinoma, can also be explained by physical inactivity and increased dietary fat intake. No established treatment exists for this potentially serious disorder. The authors present the case of a 29-year-old man with NALFD who followed a restricted diet and practiced aerobic exercise for 16 weeks. Outcome after a combination therapy of aerobic exercise and diet was good, suggesting that treatment with a restricted diet and physical exercise can improve blood biochemical values in patients with NAFLD. Moderate-intensity aerobic exercise may help to normalize liver enzyme values and the quality of life of patients with fatty liver diseases.