Is the human body really that perfect?

If so, what about decaying teeth? What about diseases?
According to the trainer, diseases, decaying teeth… are the result of mistakes in lifestyle, in diet.
Errors often instilled in us practically from birth, even forced.
And so, what was destroyed in an unnatural way, must be repaired in an unnatural way.
According to the trainer, the human body (and not only human) is perfect. Even our free will and mind, thanks to which we can destroy the body, are beautiful.