I came across this article on New Scientist and found it surprising. With at least 5 to 10% of the US population having liver disease that often goes undiagnosed, 2/3 of cases are now due to being overweight/overeating. At this point it affects people of all ages, with a number of 20 and 30 year olds having it, along with some children. Luckily I've under-eaten most of my life.
Liver disease: the silent epidemic - health - 03 April 2007 - New Scientist
Some good news of the article is that liver disease is much more reversible than originally thought, and improving one's lifestyle is often enough (at least in the earlier stages) to return to health.