Non-alcoholic fatty liver disease is a condition in which fat accumulates in the liver, the largest internal organ of the body. While the symptoms are virtually identical to those that accompany alcohol abuse, little or no alcohol consumption is involved.
Obesity and diabetes are both risk factors, meaning the disease is more common in people who are overweight, obese, or diabetic. Some people without any of these risk factors get non-alcoholic fatty liver disease, but these cases are less common.
While the incidence of fatty liver disease has increased dramatically since the early 1980s — along with the rise in obesity and diabetes — the exact correlation between its risk factors and what causes the disease are not fully understood.