In very overweight people, other genes known to affect fat and liver health didn’t change between those with mild and severe fatty liver — only SIRT1 did, making it stand out as a possible key player.

In very overweight people, only the fat around the organs (not the fat under the skin or back) shows lower levels of a protective gene (SIRT1) when the liver is very fatty — suggesting belly fat is uniquely involved.

In very overweight people, those with the worst fatty liver also had much lower levels of a specific gene (SIRT1) in their belly fat, which might mean this gene helps protect the liver from too much fat.

In very overweight people with severe fatty liver, the less SIRT1 gene activity they have in their belly fat, the worse their body’s response to insulin tends to be — meaning their blood sugar control is poorer.