Fatty liver, or hepatic steatosis or simple steatosis, is a reversible condition wherein large vacuoles of triglyceride fat accumulate in liver cells via the process of steatosis (i.e., abnormal retention of lipids within a cell). Despite having multiple causes, fatty liver can be considered a single disease that occurs worldwide in those with excessive alcohol intake and the obese (with or without effects of insulin resistance). The condition is also associated with other diseases that influence fat metabolism. When this process of fat metabolism is disrupted, the fat can accumulate in the liver in excessive amounts, thus resulting in a fatty liver. It is difficult to distinguish alcoholic FLD, which is part of alcoholic liver disease, from nonalcoholic FLD (NAFLD), and both show microvesicular and macrovesicular fatty changes at different stages.

In the present book, twelve typical literatures about fatty liver disease published on international authoritative journals were selected to introduce the worldwide newest progress, which contains reviews or original researches on grades of fatty liver, nonalcoholic fatty liver disease,  liver histology, liver enzymes and metabolic syndrome, etc. We hope this book can demonstrate advances in fatty liver disease as well as give references to the researchers, students and other related people.