Many will agree with you regarding the possible damage but fasting has been proven to benefit us in health, physically, mentally, spiritually and many other ways. Weight loss happens naturally, and is enhanced when training is added. If nobody believes me, I am proof thereof. I have no after effects from the 34km run, and I feel so good that I will try it again tomorrow but in cooler conditions starting around 05:30.
It isn't more important than your health because if you are sick, you are allowed to miss the necessary amount of days, and then make it up afterwards. If you have a chronic ailment that would require regular medication, you are exempt from fasting but you will make up for it in another way, mainly in the form of charity.
