Nonalcoholic fatty liver disease in individuals with severe obesity.

Nonalcoholic fatty liver disease (NAFLD) is a common chronic liver disorder occurring in individuals without significant alcohol consumption. It consists of a spectrum of liver disease, ranging from simple steatosis to steatohepatitis, cirrhosis, liver failure, and hepatocellular carcinoma. Although a number of conditions have been identified as risk factors, obesity is by far the most dominant risk factor for developing NAFLD. Over the past decade, it became apparent that NAFLD in some patients is a progressive disorder,leading to cirrhosis and liver failure. Despite lack of direct evidence,due to the ongoing epidemic of obesity in western countries, it is believed that the incidence of NAFLD is increasing, and patients with complicated and uncomplicated NAFLD will present in increasing numbers to primary care physicians as well as specialists. This article discusses the prevalence, histologic spectrum, and natural history of NAFLD in subjects with severe obesity as well as the hepatic effects of drastic weight loss induced by bariatric surgery or severe calorie restriction.