NAC intake for 6 or 12 months decreased liver steatosis. NAC treatment also reduced cellular apoptosis and caspase-3 expression. With regards to endoplasmic reticulum stress, only treatment at 12 months improved/reduced phospho-protein kinase R-like endoplasmic reticulum kinase and activating transcription factor 4 expression. The gene discussed is ATF4; the disease is Hepatic steatosis.