about 25-35% and you should be burning most of it
The integumentary system, the skin, protects the internal organs from harmful bacteria, sunlight, and injury. The skin is the largest organ of the body and consists of two layers: the epidermis and the dermis. The epidermis is the outer layer. It is made up of dead cells and new cells which make the body waterproof, give color to the skin, and help maintain the body's hydration levels.
