That's actually not a cure. It's a treatment, and it works, but it's not a cure.
I started doing that about 7 years ago. I was never obese, but I was overweight and I ate a lot (and I mean a LOT) of crap.
So, I stopped eating crap, and started getting a lot more exercise. I didn't lose any weight but I lost a whole lot of fat. My A1C last check was 6.1, and my glucose levels tend to be normal... but.
If I go eat a pizza right now, my blood sugar will still spike. It probably won't go a LOT above 200, but it will get there and stay there for a lot longer than a non-diabetic. Now my way of dealing with that is to never EVER eat anything with as many carbs in it as a pizza would have, and limit my carb intake to early in the day before I do the whole exercise thing.
I'm at the point where I've got it pretty much under control (much to the chagrin of my original doctor which I have since moved on from for obvious reasons) but I would love, love, LOVE a cure. Diabetes forced me to develop the tools and discipline to stay in shape, and I would likely still do that, but I do miss soo much good food.