>>69369
Consuming "normal" diet (whatever it is for an average person) and then starving the body is abuse and unhealthy.
Plus it's a fallacy that "if people back then couldn't eat each day then humans weren't made to do that so we have to mimic that pattern". Back then humanity had no access to lots of things we have today. Sure not all stuff is a blessing, but some it's better to have. And probably many undecided or depends on the individual.
I do agree that keto diet isn't necessarily a good thing. My general thought is what we should aim for is reducing the quickly absorbable carbohydrates (pure sugars, starchy stuff), but even these have place in the diet, and even value to health. I also think we would do better if we consumed less processed foodstuff. It would be great to have access to real milk, under the cow or goat or sheep or buffalo or whatever.

There's this telly show - I'm not sure if they still make it, it has over 10 seasons - titled Alone. Look up the details wherever.
The participants generally starve and go into ketosis.Their main source of food is usually fish, some can catch small game: mice, rats, squirrels, rabbits, some winners have access to big game like moose or bison. They can round out their diet with mushroom, berries, some leaf and root plants (like dandelions or nettle), which lack calories to begin with, but as they go into winter these are less and less.
What they really miss is carbs and fats - all wild meat is lean, except perhaps porkypines then even those aren't like pigs.
Two months is a long time for a participant staying out. Tho most fail due to loneliness, not for their diet.