I realise this is the weight-loss forum, but diabetes and obesity are inextricably linked, and we seem to have had quite a few posts on the subject lately. I was unable to respond to lucigret's tag on a closed thread, so herewith a few thoughts on the subject.
1) Back when my mum was a ward sister, diabetes was almost unheard-of. Those few cases who did appear were Type 1. Type 2 was such an obscure condition that, if a case turned up, all the medics would cluster around and prod and question the poor patient.
So let's be clear about this: T2D is not just "one of those things" that strikes at random. It has a very specific dietary cause: synthetic foods which our bodies have never encountered before, stuffed full of easily-digestible carbohydrates and lacking fats - often because the fat has been artificially removed. If you stop eating in that specific way, your chances of acquiring T2D drop dramatically.
2) Diabetes is not caused by obesity. We know this because about 30% of cases present with a more-or-less normal BMI. Obesity and diabetes are both a consequence of a body failing to adapt to repeated and excessive doses of glucose-based energy (carbs and sugar). Your body can adapt to virtually any diet that doesn't cause this scenario ... as is very apparent by looking at the wide variety of healthy diets consumed worldwide, or historically.
3) If you already have T2D, it can be painlessly and quickly reversed with what is inaccurately called a "low-carb high-fat" diet. This name is actually a pejorative, invented by vested interests in order to imply that it's unhealthy. The correct term should be "moderate carb adequate fat", or something along those lines.
Nevertheless, I'll keep using the term "LCHF" here, mainly because that's the name of the HU group associated with this way of eating.
4) LCHF has been repeatedly shown to be the most effective way of reversing T2D, and the NHS Diabetes Prevention Programme is endorsing it in certain areas. It's main benefit is that it is sustainable in the long term. The food is tasty and you can eat until you're full: essentially, it involves eating good old meat and veg, as humans have done for millennia. Your appetite quickly adapts to it, and you stop wanting bad food.
5) The competing therapy is known as the Newcastle Diet, which is an ultra-low-calorie diet based around food substitutes. It has a broadly similar success rate (~60% complete remission) but it is very unpleasant, and in fact it works in exactly the same way as a standard LCHF protocol: it reduces the carbohydrate load on your body. The difference is that it also reduces protein and fat, without any theoretical justification for doing so. The long-term efficacy of the ND is unproven, but since the patient is not told why his condition occurred in the first place, and what he can do to prevent it, relapse seems inevitable.
The TL;DR version: Diabetes Type 2 is easily reversible, and if you do it right, it stays reversed. It is not a progressive, permanent condition. If anyone feels it might be the right course for them, the LCHF group is a welcoming place with lots of knowledgeable people - including a few who have successfully reversed diabetes or prediabetes.