Thanks to all for your point of views and info.
I’m not gonna say I’m an expert at this but I have done extensive reading of books and peer reviewed medical studies, along with watching a great many hours of youtube videos, taking notes and learning what I can of the science behind this practice. From what I can tell, the body of knowledge is very limited and will probably stay that way since the general public is “scared” of fasting and there is so much money “on the other side” (selling us food/kitchen equipment/athletic gear and supplements etc…).
As with most things of this nature, a book, a video, a study, a certified personal trainer, a dietitian etc can’t tell me, with 100% certainty will and will not work for me. You hear it all the time in the area of nutrition/diet/exercise, you have to experiment and see what works for you.
Case in point, the Fung video listed earlier, great stuff and Fung says in the video that he doesn’t do longer fasts because they don’t fit into his life and he’s at a goal weight, he says the only reason he could think of doing a long fast if you are at goal weight is for the challenge, one of my motivations (I’ve consumed A LOT of Fung’s media, to the point that his verbal ticks [you know] have become annoying, still have massive respect for his POV).
As for Phinney, I’m aware of the “controversy” created by his statements but the way I understand it is that he’s said you COULD lose lean tissue but I agree with many who feel Phinney is being overly cautious (and I have a great deal of respect for Phinney as well).
Thanks again for the comments and feedback, I welcome them and enjoy the back and forth on this forum, it’s not facebook shouting wars and people getting overly emotional, very refreshing! Keep calm and fast on!