Same disclaimer as you on expertise, but cancer basically comes from one mutation when a cell divides that causes it to start dividing out of control. So if you manage to starve all of those out of control cells to death, you've eradicated the cancer. The caveat is that you've got to kill _all_ of the cells, not just most of them.

Dumb question: why two months? Doesn't it depend on your fat reserves?

If you are 350 pounds, can't you just not eat until you are 150 and be fine? (I am not suggesting that this is true or that anyone should try it; I don't know and I am asking the question.)

With respect to energy, that’s apparently true.

However, metabolism has non-energy needs which are supplied through food: vitamins, minerals, protein, and some fats that cannot be synthesized iirc. Though these needs are greatly reduced when fasting, they do not go to zero.

Google “angus barbieri” for the most famous, though not unique, example for medically documented long term fasting.

It certainly has been done: https://en.wikipedia.org/wiki/Angus_Barbieri%27s_fast