This study investigates the lipid composition of the liver in patients with nonalcoholic fatty liver disease (NAFLD), including nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis (NASH). The researchers quantified and compared the levels of free fatty acids (FFA), diacylglycerol (DAG), triacylglycerol (TAG), free cholesterol (FC), cholesterol esters, and phospholipids in normal livers, NAFL, and NASH. They also analyzed the distribution of fatty acids within these lipid classes across the groups. The results showed that DAG and TAG levels were significantly increased in NAFL and NASH compared to normal livers. The TAG/DAG ratio increased stepwise from normal livers to NAFL to NASH. FC levels also increased stepwise, with a significant increase in NASH. Total phosphatidylcholine (PC) decreased in both NAFL and NASH, while the FC/PC ratio increased. The n-6:n-3 fatty acid ratio increased in NASH. The study also found that arachidonic acid (20:4n-6) and certain n-3 fatty acids were decreased in NASH, while linoleic acid (18:2n-6) and α-linolenic acid (18:3n-3) remained unchanged. The study concludes that NAFLD is associated with significant changes in the lipid composition of the liver. These changes may have important implications for the pathophysiology of NAFLD and the metabolic syndrome. The findings suggest that the lipid composition of the liver in NAFLD is complex and that further research is needed to understand the mechanisms underlying these changes and their potential impact on the progression of NASH. The study also highlights the importance of n-3 fatty acids in the prevention and treatment of NASH.This study investigates the lipid composition of the liver in patients with nonalcoholic fatty liver disease (NAFLD), including nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis (NASH). The researchers quantified and compared the levels of free fatty acids (FFA), diacylglycerol (DAG), triacylglycerol (TAG), free cholesterol (FC), cholesterol esters, and phospholipids in normal livers, NAFL, and NASH. They also analyzed the distribution of fatty acids within these lipid classes across the groups. The results showed that DAG and TAG levels were significantly increased in NAFL and NASH compared to normal livers. The TAG/DAG ratio increased stepwise from normal livers to NAFL to NASH. FC levels also increased stepwise, with a significant increase in NASH. Total phosphatidylcholine (PC) decreased in both NAFL and NASH, while the FC/PC ratio increased. The n-6:n-3 fatty acid ratio increased in NASH. The study also found that arachidonic acid (20:4n-6) and certain n-3 fatty acids were decreased in NASH, while linoleic acid (18:2n-6) and α-linolenic acid (18:3n-3) remained unchanged. The study concludes that NAFLD is associated with significant changes in the lipid composition of the liver. These changes may have important implications for the pathophysiology of NAFLD and the metabolic syndrome. The findings suggest that the lipid composition of the liver in NAFLD is complex and that further research is needed to understand the mechanisms underlying these changes and their potential impact on the progression of NASH. The study also highlights the importance of n-3 fatty acids in the prevention and treatment of NASH.