Our liver is one of the main visceral organs handling and controlling all of metabolic pathways to make healthy our life. Over capacities of the liver to do the job generate the disease. A fatty liver disease is a primary disease that is initiated by excess accumulation of lipids in the liver generating steatohepatitis and even cirrhosis. This book described in detail a biochemical mechanism of the disease. The development of the disease involves an important role of the orotic acid intermediate metabolites from the pyrimidine nucleotide biosynthetic pathway. The development of the disease is inhibited by the shochu kasu. A beneficial function of the shochu kasu is to alleviate the disease. All those mechanistic developments and inhibitions of the disease found in this book are described in detail at molecular level. Overall, this book provides a useful discussion on the fatty liver disease from the initiation of the disease until its mechanistic inhibition. This book provides useful information for food product designers, industrial scientists, and every one who intensive study on liver function as well as the graduate students.