I need to weigh in here ( no pun intended).
I had stroke in 2007 and after 4 years battling latest mess - was 30 years plus as T2 I would offer some thoughts.
Not Doctor so cannot give advice but:
I had got to 330 pounds on diet of 1200 calories and 2 miles of walking and could not lose an ounce till liver crap and over glucose release shut down by metformin doses appropriatly done. Large single doses are waste of drugs and do not address issue.
Liver's role as fifo buffer filling in when BG drops sub 70 can be real pain in ass.
Liver is great doing this when it only adds 20 % above nominal. If it is adding the full liver buffer each time it dumps or large portion of this, ones BG level quickly gets too high and one cannot lose weight.
Once liver excess glucose stopped and managing diet so that it keeps BG above 100 per Doctor's advice, I lost over 100 pounds on same 1200 calorie diet and 2 miles walking and health returned.
SO much useless advice out there makes erroneous assumption human body mostly working correctly when in fact there may be medical screwup over riding that.
Low glycemic diets are great as long as liver mostly working correctly. If not low glycemic diet is going to routinely drop BG sub 70 and kick liver into gear adding glucose and depending upon issue see bg hammered up to 511 and average back to 278/311
buggering up glucose control.
My health is back and I am much happier but am fed up with all the mis information and bum advice out there. See Salk Institute and John Hopkins CHildrens research on metformin and its real miracles not discussed in the approved cures et all.