I’m going to toss out something that worked for me but I’m not going to spend time in this thread defending it so if it doesn’t seem like it will work for you, I get it.
About 5 years ago my company starting health screening as a part of each participant’s health insurance cost. You didn’t have to get screened and screening would not hurt you by increasing your premium but it could help by decreasing your premium. Being a fairly fit guy for most of my lift I took the challenge and I scored 4/5. That was stunning but the reason for not scoring 5/5 was my A1C level. So I did the normal thing most people do which was not go to the doctor but instead I googled how to fix it 
I spent 14 months pretty much living by the diet outlined in that book.
My A1C went from 5.8 to 4.2-4.4 ever since. I don’t eat paleo anymore. My assumption is that the combination of regaining some insulin resistance and being very fit was enough for me to adopt the Nate diet (carbs and more carbs) and really not have my levels impacted by doing so.
So that’s what worked for me. N=1, your mileage may vary and all that stuff.
Good luck!