This article is full of good stuff. A couple quotes:
“The crucial piece necessary for development of insulin resistance is not overall obesity, but fat contained within the liver, where there should not be any. This is the reason that there are underweight patients, as defined by the Body Mass Index, who still suffer from type 2 diabetes. These patients are often termed “skinny diabetics” or TOFI (Thin on the Outside, Fat on the Inside). Overall weight matters less than the fat carried around the midsection and the liver. This central obesity, rather than generalized obesity is characteristic of the metabolic syndrome and type 2 diabetes.”
“In type 2 diabetic patients, there is a close correlation between the amount of liver fat and the insulin dose required reflecting greater insulin resistance. In short, the fattier the liver, the higher the insulin resistance.
By contrast, in type 1 diabetes, insulin levels are extremely low, and liver fat is lower than normal. This is strong evidence that insulin levels are a key causal factor in developing fatty liver. Insulin drives fat production in the liver and low levels of insulin lead to less fat in the liver.”