Even in people who are obese and healthy (normal cholesterol, blood pressure; little fat accumulation in the liver) often progress to unhealthy. This is particularly true of intra-abdominal fat (“beer belly” or “soda belly“). Fat under the skin, in the legs, buttocks, etc is less unhealthty.
Unhealthy is when the fat cells start to act poison, die, and set inflammation in place. I used to presumably have fatty liver (abnormal liver blood tests). Some people think that obesity will surpass alcoholism as a cause of liver cirrhosis, because the inflammation in the fat that fills the liver can scar the liver eventually.
After losing 130 lbs, my liver tests became normally – they were high before.