Okay, Metformin helps hold back glucose creation (gluconeogenesis).
Helping to keep your glucose lower.
Mine was in the mid 90s even on carnivore. But it was demand driven. My brain was using all of my glucose, and my muscles were sparing it for the brain.
Taking Metformin the first time actually led to night time tachycardia! As my glucose dropped, my brain then sees the drop as an emergency and pushes a fight or flight response, and it works, my glucose comes up…
The side effect was that during the day, my brain had to learn to work on a lower glucose. And over a week or two, I was now programming with an 85 Glucose, as my brain was becoming less glucose dependent (using ketones more).
My Doc guessed this might be happening. Because my ketones were sky high (4.6) after a weekend fast, and my glucose was 78. The best description I could give you is that I had the “wrong” energy. I felt physically able to do anything… But measuring my time to do Sudoku, etc. And they were horrible. Thinking was just “hard”. (I could vegetate in front of a video/audio, but writing software was basically impossible)
Those pathways in my brain for programming, were ALWAYS amped up by glucose (full sugared soda) and caffeine. For 40 years! (Laughing at the damage I was doing without realizing it).
Anyways, since I am mostly carnivore, all this glucose was symptomatic of demand/stress. And it has a real downside in that I could have plenty of ketones, but I get hit by the HANGRY version of mental fog… A couple of hours of programming starts feeling like a couple of hours under duress… Especially when I am on Metformin. So, I have opted to cycle on it for a week or two, and cycle off for about a month (I hate being on ANY Rx drug).
I have the rest of my life to figure this out… Now, I CANNOT prove a word I wrote. It was a theory my Doc came up with, and it matched my symptoms pretty well. His thought process is that every organ can independently be at a different level of keto adapted… And despite the literature saying “your brain prefers ketones”, he explained that is a “generalized” statement.
In your case, programming while bathing your brain in glucose may have trained those pathways.
I know how I feel, and how I felt. And I now that my lower glucose has NOT been preventing me from programming. Although a lack of caffeine seems to hold me back… That’s probably just because I’ve basically self-medicated my ADHD with caffeine my whole life so I could function…