There is a lot of concern that a ketogenic diet may negatively impact liver health. But studies on keto's effects on liver health and functioning show varying results.
Some studies found that keto can lead to non-alcoholic fatty liver disease (NAFLD) [1] while a large number of studies found that keto had a therapeutic effect on NAFLD, meaning it improved liver health in those with a fatty liver [2]. So the link between liver disease and keto is controversial.
What we certainly know is that having diabets and being overweight are two major causes of NAFLD [3]. Since keto tackles both, it's more likely that keto can do your liver more good than harm.
Eating a balanced ketogenic diet with just enough protein and plenty of fiber will help you maintain a healthy weight and metabolism that also translates to better liver functioning. Still, if you have reasons to worry about your liver health, do speak to your doctor about starting a ketogenic diet.