So much good information to unpack in this interview. I am pleased to hear that ketones suppress the use of lean mass for energy, as this has been debated for quite some time, and I don't think the debate is over, but for my n=1, I find that fasting with only water and some electrolytes has no perceivable effect on my lean mass. I emphasize perceivable, as I'm not measuring changes in types of mass.

Also, information about IGF1 stimulated with consumption of protein coupled with the importance of IGF1 and the negative consequences of too much IGF1. I believe there are multiple factors at play here, as IGF1 is both essential and is often associated as an indicator of the presence of cancer. Given the active discussion on the optimum daily protein intake, I'm starting to view necessary protein consumption in the context of the food consumed. For those eating a SAD, increased protein consumption can be detrimental. For those eating low carb, I believe there's an an extended "healthy range" where in the presence of healthy whole foods, protein is beneficial. Coupled with fasting where IGF1 production is reduced, this quiescence period of no protein and no IGF1 production stimulates ketone production, autophagy, and stem cell regeneration. We require protein, but the quiescent period during a fast enables metabolic repairs. Once protein is consumed after a fast, IGF1 production ramps up and the rebuilding starts. It's only when one is consuming 3 meals a day plus multiple snacks that the system breaks down. We weren't meant to consume fuel like that.

Edited to correct acronym.