Let’s say you are dying of starvation. You pull one of your teeth out, causing blood to slowly seep into your mouth, which you swallow. The calories from the blood getting digested will delay the time you die of starvation, right? Or will losing blood while starving kill you faster?
You can never, ever get a net gain from self cannibalism of any kind. Digesting takes energy, and you’re also having to heal/replace whatever it is you’re eating.
Besides, the amount of blood that will come from a pulled tooth isn’t enough to do anything useful. You wouldn’t even gain minutes from it if the source was external.
If you have calories in your blood, you should leave them in there to get used instead of taking them out and back in. You wouldn’t be adding usable energy, you already had it.
You have energy stored in fat and muscle, but your body already is going to try and consume those without all that added stress of eating yourself from the outside.
I’ve read a story of a 3 year old that had to have his tonsils removed. The poor child didn’t understand that it’s not good to swallow so much blood, didn’t know enough to tell his parents what was up, and he unfortunately passed away, with a belly full of blood ☹️
