I just came in from 20 minutes of raking the flowerbeds out it's 77F(25C) Worked up a sweat and checked my blood sugar 103, YAY! I ate a small lunch a couple of hours earlier.
Problem is, I can't work like a laborer all day -- but exercise is the ticket for me -- the worst I have seen is a peak around 200 that was 30 minutes after a meal. You fast when you sleep but are inactive (sleeping). Maybe you are sleep eating
It has to be a metabolic affect. Maybe exercise 10 minutes when you wake up in the middle of the night to take a piss?