We all have a doctor inside of us; we must only assist him in his work. The natural power of internal regeneration is the greatest strength we have to recover health. Our food should be our medicine. Our medicine must be our food. But to eat when you are sick is to feed the illness." Hippocrates, Greek physician, considered the father of Western medicine. We believe that a sick person needs to eat to recover his strength. Why then does a person get sick even when he eats on average more than three meals a day? Fasting is a practice based on the instinct and has been practiced by the animal kingdom since the beginning of life on earth. Every wild animal, when injured or sick, simply loses the desire for food and fasts, until its hunger and energy return. Fasting is practiced by every living organism on the planet, except for the modern human being. The "civilized" human being is the only animal on the planet that goes against the instructions of its organism and feeds during illness, despite all the physiological signs such as loss of hunger, muscle prostration and the cessation of gastric secretions. In this book you will discover why the human body has the inherent ability to regenerate itself, promoting the self-healing of virtually every type of ailment that afflicts us. You will see that the loss of hunger and the prostration of illness have a reason. You will learn that, during human history, many distinguished medical figures defended fasting as the ultimate form of self-healing and that it was seen by health professionals who used it as "nature's surgery". You will see that science proves that fasting not only improves health enormously, it also rejuvenates the body and prolongs life in countless years, making the clock "go back in time". As hygienists claim: FASTING CAN SAVE YOUR LIFE.