The body does renew the skin during an extended fast. The skin is an important part of the elimination system. I had stretch marks from my obesity before fasting last year and expected more stretch marks from losing the weight so quickly with fasting. The opposite happened in fact, my stretch marks all but disappeared- you just can't see them unless you are really looking for them and moving the skin around a bit. My other scars have not healed completely, but have all faded to some degree. Fasting is definitely good for the skin.