A longer outtake from the paragraph I was quoting:
It is well known that people with schizophrenia are three times more likely to develop diabetes. A common debate in the field is whether the antipsychotic medications, which are known to cause weight gain and diabetes, are to blame. Recent research suggests that this is not the entire explanation. Even people newly diagnosed with schizophrenia appear to already have insulin resistance, even though most don’t yet have diabetes. This means that their brains may not be getting enough energy from glucose. Other brain studies have found metabolic abnormalities, such as higher levels of oxidative stress and inflammation as well.
Recently, it's been observed that the rate of new diabetes cases is declining, while obesity keeps going up. Nobody knows what's going on, even though we are bombarded with theories.
I remember (I think) reading a long time ago about how someone had linked insulin resistance to pain nerves (or maybe taste nerves, I forget) found in the pancreas - even though you don't perceive with them consciously. I wonder if anything came of that research.
I doubt that it's that straight forward. Inflammation is associated with both chemical derangement and infection. Probably other things as well, like allergic reactions.
Insulin resistance has also been linked to inadequate muscle mass more strongly than to excess fat per se.
It is well known that people with schizophrenia are three times more likely to develop diabetes. A common debate in the field is whether the antipsychotic medications, which are known to cause weight gain and diabetes, are to blame. Recent research suggests that this is not the entire explanation. Even people newly diagnosed with schizophrenia appear to already have insulin resistance, even though most don’t yet have diabetes. This means that their brains may not be getting enough energy from glucose. Other brain studies have found metabolic abnormalities, such as higher levels of oxidative stress and inflammation as well.