Obesity and the liver: developmental perspectives.

Obesity now affects 15% of children and adolescents in the United States. Many of the complications of obesity are seen in children, including fatty liver disease, gallstones, hyperlipidemia, insulin resistance, and type 2 diabetes. Infants and children also have unique susceptibilities to and manifestations of liver disease caused by total parenteral nutrition. In addition to genetic and environmental influences on obesity, there is increasing evidence supporting the idea of "metabolic programming," in which environmental influences at critical periods during development have permanent effects on an individual's predisposition to obesity and metabolic disease. Understanding the role the liver plays in the development and expression of the metabolic program will provide important insight into the pathogenesis and treatment of fatty liver disease, and of obesity itself.