Done it myself, it works.....lost circa 2stone 5lbs (5'7" tall, originally weighing 14stone). Waiting for the official result from my latest HbA1c (was starting in Jan 19 at 58 mmol/mol), but by tracking my own blood glucose at various times each day (x4 - 6) pre and post prandial, estimated HbA1c is possibly around the 30 mmol/mol expectation - fingers crossed.
I seem to recall reading in a clinical study that (subject to BETA cell production not being compromised in Islets/Pancreas) a 1g reduction of visceral fat around the Pancreas will allow the organ to produce Insulin again, albeit not usually at a non-diabetic level. The body's own resistance to Insulin is another story, but by judicious use of lifestyle adjustments (e.g. Low Carb, High Fat and Exercise) then there seems to be genuine validity as suggested by various endocrinology resources. The reliance on prescribing drugs such as Metformin (SR/ER) and alike, whilst may be essential in some cases, is seemingly far too readily churned out to every new diagnosis, and there seems to be a financial element that sways this decision making process. That said, there are benefits allegedly in prevention of cancers and such?.
In subjects, if you are storing excess visceral fat around the upper abdomen, then this is a very high marker for T2 Diabetes risk and also the main area to remove if subsequently diagnosed. Genetic factors are also slowly being recognised as a main contributor alongside lifestyle and food habits in the modern day. Carbs in the main are the enemy, and are heavily prevalent in most quick and easy foodstuffs demanded in a hectic lifestyle that we all tend to subscribe to, thus avoid to a high degree if possible - your blood glucose meter (if you get one, or buy one) will allow you to see the effects of various foods. As a previous poster mentioned, the 'hip-to-waist' is a far better ratio to review periodically as a guide, as the BMI calculators are a little mis-leading?.
Be wary of the advice that is given on some of the sites that purport to be an official resource - A special style of diet is required to prevent the loss of limbs, neuropathy, retinopathy etc. etc. and to believe otherwise is to fool yourself. That said, you can enjoy some of the nice things you once did, as long as its occasional and not every (other) day. Some say you cannot, but that's simply not true unless you have no self-control.