Non-Alcoholic Fatty Liver Disease, better known as NAFLD or NASH, is a known entity in adult medicine. It occurs when the fat component of the liver is greater than 5 percent of the liver's weight. It is strongly associated with obesity and insulin resistance, although not always. As many as 25% of the US adult population has NAFLD.
Now NAFLD is not just a disease of adults, but it also a pediatric entity. As many as 10% of children may have NAFLD. It's prevalence is as high as 80% in obese children. It is still unknown whether lifestyle modification and/or medications may help these children. This is currently an area of research. It makes logical sense that exercise and proper diet, along with weight loss back to a normal weight, would help these children, but we do not as of yet know if the damage they incur while obese carries over once they are normal weight.
What we do know is that normal weight children, who are active and eat a nutritious diet, are much much less likely to get NAFLD. This is just another reason to encourage our patients to live healthy, both for themselves and their children/grandchildren.