Any human body can achieve maximum health and vitality after a very prolonged diet of moderate consumption of raw vegan food.
Fasting/breatharianism is added into the mix as a means of listening to the body and understanding that starvation/thirst is a total myth, and the body is actually built to survive without food or drink.
Someone who did this diet for this prolonged period of time would be able to jump into breatharianism like it's nothing.
I can jump in based on sheer consciousness alone, I've done very long water fasts (25 days) in past years when I was actually an unhealthy eater, so I know everything I say here is a fact.
Ultimately I think that a lot of this topic is being overthought.
Just do the right thing for yourself and realize you are not the body nor are you the mind! This understanding and its application to gain greater understanding is what will truly free your consciousness. There are so many things you can do apart from thinking and working on your diet even though that is an unavoidable aspect simply because of the way the human world is structured at present time.
Love and light