Since this hormone plays several metabolic activities such as decreasing lipolysis, increasing fatty acid oxidation in adipose tissue, decreasing hepatic lipid levels such as diacylglycerol, increasing insulin sensitivity, and improving glycemic control, the elevated circulating FGF21 levels observed in people with NAFLD have been suggested by several studies to be an adaptive mechanism to maintain energy homeostasis under metabolic stress [35]. This evidence concerns the gene FGF21 and metabolic dysfunction-associated steatotic liver disease.