Questions about fasting on keto after reading Lyle McDonald's book.

The fat in fatty liver would be fat mass, not lean mass but in any event wouldn't be more than in the grams range. Regarding Lyle's numbers, the brain uses 100g-120g a day when not in ketosis, and drops to 40g when in deep ketosis after a few weeks. So you better be getting enough protein to at least make up that other 60g-80g of glucose via gluconeogenesis.

Even Lyle doesn't advocate straight up fasting..His rapid fat loss handbook is a PSMF and he pushes something like 100g-150g IIRC (read it years ago) of protein for that.

But even that won't stop the rising cortisol and glucagon from plummeting leptin levels shunting protein, which would be used for growth and repair into gluconeogenesis. There is a reason women's hair falls out when they diet hard, and natural bodybuilders lose a lot of muscle dieting down to 6-8% BF. Nevermind all the studies showing a negative nitrogen balance during long term fasting, which Fung refuses to acknowledge.

And I'm not getting into the rising adiponectin just waiting to cause WAT hyperplasia from insulin hypersensitivity due to even lower leptin levels than wouldn't occur if long term fasting wasn't involved.

That said, the shorter term fasting that you describe wouldn't cause such serious systems. From the research I've seen, you can push it up to 72 hours before the bad stuff occurs, although you might want to get your gallbladder checked a few times or take some ursodiol for prophylaxis.

/r/ketoscience Thread