Really interesting discussion. It sounds like no one is going as low protein as Dr. Gundry's recommends. I find it very interesting that his approach marries a neuroprotection ketogenic diet (a la Perlmutter) with a CR/longevity twist. Sort of blending my approach with James's or G's.
FWIW, I'm eating around .8 grams of protein per kilo (about 46 grams) daily and it yielded me an IGF-1 of 121. That's the first time I've paid attention to that marker so I have no context. My guess is that I could go even lower with animal protein to further reduce it. I've been mildly ketogenic for several years, with lower protein the last 6 months, and I have found it extremely Important to engage in some moderate strength training to avoid catabolizing muscle. No big deal.
Hep, your description of glucoseneogenisis is fascinating. I always hear the term used in the context of a ketogenic diet with too much protein. BUT, I most certainly experienced the phenomenon when I was displaying symptoms of IR, eating a primarily LFHC diet. I had constant severe hypoglycemia with sky high cortisol. Now, that I'm mildly ketogenic with no signs of IR, my cortisol is perfectly normal.