Again, I would want to see if the actual factor is a placebo, that of attention to the diet. The more you know about your food, the more you will respect your food and not overdo it.
The people that over do it are not the ones that end up type II diabetics. It is slightly more common in vegetarians than normal eaters, and particularly uncommon in heavy meat eaters. Cutting out sugar and starches will help but won’t do the trick alone; you have to eliminate all polyunsaturates and man made fats.