I am diabetic type 2 and take statins and metformin. I am on a strict ketogenic diet, carbs < 20g/day. I asked Dr Jason Fung on Diet Doctor the following: When in ketosis I may be relying on gluconeogenesis to produce glucose for my brain. If the Metformin I am taking inhibits glucose formation, might this limit the amount of energy supply to the brain and produce symptoms of fuzziness and becoming light-headed? His reply was "It's definitely possible". A bit worrying, as I do suffer from a fuzzy head that I normally attribute to keto flu. Has anyone heard of this sort of problem with metformin?