I recently lost 25kg in 4mths from 105kg and my fasting went from 7 to 4.5, Hba1c from 54 to 33 and I passed an ogtt with 5.2 (2hrs). I now eat around 250gcarbs per day and have lost another 3kg since then. If you are lightly active, at 5ft 10, you would need 3150kcal/day to stay the same weight. Replacing carbs with fat will lower blood glucose but fat has more than double the calories than carbs so a small slip of the "healthy" oil will add hundreds of Calories to your intake.
If you cut your Calories to 2200/day you would have lost 40kg by end of Feb 2015. 4 meals of 500 Calories a day, of whatever macronutrient ratios you like, is what I would do then store 200/day for treat every few days. I had good success on 2 meal replacements and 1 veg meal totalling 1200Calories but I did lose muscle, but it is back on now, maybe too severe restriction . Best of luck