I don't think you can don't off health regen with the prefs ini file, can you? For that, i think you have to use a mod.
A console command can do that, but i forgot which one. "Set player.something to 0" IIRC.
Edit:
"set player.HealRateMult to 0"? No, that does nothing. I remember doing it, but not how i did it

Edit 2: "player.setav healrate 0"