Thinking back, trying to remember Dr. Fung's comments on insulin resistance, and the different kinds, liver specifically and wasn't there also brain insulin resistance? Meaning, glucose not being taken up by the brain tissue because of insulin resistance? Wouldn't that explain it? Given that these people were either obese or poorly controlled diabetics, IR is more or less assumed.

I would also wonder about inflammation, which could also be assumed in those two groups, being a factor.