Which is a shame because I feel that Dr David Unwin, Prof Tim Noakes, Dr Gary Fetke , Virta Health and many others have greater success by using a Low Carb 'Way Of Eating' and focussing on reducing the BG rather than a Calorie Restricted Diet .
Just a piece of anecdotal information, my experience, so not something everyone will experience. For me, weight loss wasn't the key thing in bringing BG under control, it was the lower carbs.
I had taken Rosiglitazone for a few years back in the early 2000s. I had a weight problem to begin with and although less calories had previously helped me lose weight, it didn't seem to work any more and worse still, with Rosiglitazone which helps the pancreas produce more insulin, my weight shot up to 163 kgs. I'm not sure how I could have controlled or prevented that weight gain because I already 'watched what I ate'. I didn't eat processed food including things like biscuits, chocolate, cake etc. I didn't drink alcohol either. One thing I can say is the it was a period of time when I didn't weigh myself because the scales had broken and I did nothing to replace them, bad mistake.
When the GP noticed my deteriorating liver function, caused by the Rosiglitazone (which is why it's no longer available) I stopped taking it and the weight literally fell off, until my GP prescribed Gliclazide, another drug to make the pancreas produce more insulin. I had however lost about 20 kgs. It took a low carb diet to lose another 20 kgs. At least scrapping carbs meant I no longer took the Gliclazide or the Januvia and also threw out the statins because my total cholesterol was so low.
I think with the low calorie diets such as the Newcastle, it is also a low carb diet, lowering calories has to lower carbs, unless carbs becaome a bigger percentage of your calorie intake.
The other thing we should do is define 'Reversing diabetes'. For me, if I can ever go back to eating bread, toast for breakfast, roll for lunch (not so bothered about carbs for dinner, I love my veggies, so no room on the plate), without any problems with BG, then it's reversed. I suppose to make sure I'd have an insulin resistance test.