> Vegetarians and vegans have lower T2D incidence on average FWIW.

Anecdotally, my dad tried vegetarianism for quite a while to address his T2D, but it had no effect. My mom cut out sugar and processed carbohydrates and her T2D was gone in ~3 months or so.

Following any diet is probably better than nothing at all, which could explain the lower incidence of T2D in that group vs the general public. I’d be more curious about the rates in vegetarians/vegans vs people who eat paleo or even carnivore.