The book you hold in your hands collects the experiences shared among clinicians and basic researchers related to liver disease by non-alcoholic fatty deposits. These experiences have been discussed in different meetings held in León (Spain), trying to comprehend in its entire dimension a process that is currently the most common liver disorder in developed countries. This collection of experiences is not intended to explore all aspects of the problem but those in which the different authors have a relevant opinion. We hope you enjoy reading while you can discover nuances that help you have a broader view of this reality that is the pathological deposit of fat in the liver.