Fat is active tissue that secretes biochemicals called adipokines that fuel inflammation in other tissues and promote insulin resistance. It is an active site of inflammation. It intrudes into other tissues such as the liver, the pancreas, and the pericardium of the heart. What do you call tissue that grows without limit, is attacked by the immune system, and intrudes into organs and tissues, stealing their space and nutrients and interfering with their function? A tumor.
This fat tumor can bring about type 2 diabetes. This has been known for some time, but here is a new study in the BBC that makes it clear that diabetes can be reversed by a reduction of fat mass.