From our previous discussions about the “sugar” diet, the key mechanism appears to be stimulation of FGF-21 which is triggered by protein sparing, and not sugar.
FGF-21 decouples mitochondria from cells and appears to increase basal metabolic rate by ~20%.
MD Shawn Baker does a protein sparing carnivore diet experiment (butter only) for 3 days - which should also stimulate FGF-21 increases.
Shawn Baker lost 4.5kg (10lbs) in 3 days doing this protein sparing diet.
THIS DIET IS NOT HEALTHY! You need protein.
We have discussed this before as a “fat” fast, but never in the context of FGF-21.
From a evolutionary perspective I’m not sure what benefit humans get from FGF-21 basal metabolic rate increases.
i.e. when fasting why increase the daily burn rate at all?
That’s not how evolution works. something doesn’t need to confer an advantage to hang around, just not enough of a disadvantage to matter for survival.
it may also be coupled with something that does confer a non-negligible advantage that we don’t know about.