Dr. Roy Taylor, through studies using the ND (Newcastle Diet), is finding that drastically lowering calories will quickly remove fat from the liver in the first week. This starts to restore liver / glucose functionality. If the diet (800 Kcal / day) is continued for another 7 weeks more fat is lost from the liver AND fat in the pancreas is lowered and beta cells begin working again.
After 8 weeks, initially 7 of 11 diabetics with short term or pre-diabetes were successful in reversing their diabetes. A second study included people with longer term, 10+ years after diagnosis with much lower number of reversals. Currently a third and larger study is underway and data should be coming out in December 2017.
I haven't made up my mind about all this yet but still looking into it. Here's a link on youtube:
So another answer to your question might be:
1) reduce carbs to about 30 - 90gms daily
2) reduce blood sugar to non-diabetic levels
3) reduce calories to a 300 kcal deficit and
4) lose about 15% of your body weight.
Hmmmm, Sounds like LCHF to me.