Lots of good info in here. At risk of oversimplifying a complex issue:

Fasting for roughly 72 hours will enter the body into a deep state of autophagy, self consumption. The strong cells consume the weaker cells in this state, mutated cells are weaker cells much like supposed "covid variants", cancers are those weaker cells. The cancer is now in a starved and exposed state, the stronger cells will consume those weaker cells that consume all the sugars you consume before you use them, even cleaning up some necrosis and things of that nature. Very good self maintenance.

You are playing chicken - starving out between a small mutated cell and an entire human body with fuel reserves designed for the long haul. You've got all your fat reserves and muscle tissue if you go too long, those bastards just have short term sugar access. This requires nothing but strong will for the first 24 hours. It's easy after that. Tip for it being made easy, if you just don't eat past supper. Say 6pm, no snacks that night, by 6am you are already 12 hours in and possibly still sleeping. 18 by noon, and you should be into a decent ketosis (fat reserve) and not have an appetite. It's easy from there, the cell autophagy if I recall, really kicks in around 36 hours in and by 72 hours deeper and more proficient clean up occurs.

Dr Berg is a great resource, unfortunately he is a scientology goon lol, yuge discredit. But his accessibility to simply compiled research is unmatched. He has several break downs of the difference phases the body goes through during these deeper fasted maintenance states.

Bless you and yours in Jesus's name.