NAFLD and ALD are marked by hepatic steatosis, liver injury, inflammation, fibrosis, cirrhosis, and HCC. Alcohol consumption or a high-fat diet impairs autophagy, resulting in intracellular accumulation of damaged mitochondria, MDBs, and excessive LDs. Autophagy relieves hepatocellular steatosis and liver injury by degrading these intracellular toxic components. The up and down black arrows indicate increased and decreased in individual level or activity. Abbreviations: NAFLD, non-alcoholic fatty liver disease; ALD, alcoholic liver disease; HCC, hepatocellular carcinoma; MDBs, Mallory-Denk bodies; LDs, lipid droplets.