Book excerpt: The author of this paper, Ewa Dąbrowska, M.D., Ph.D., is one of the very few doctors in Poland who have come to understand that the main cause of common and diverse degenerative diseases (also called “diseases of affluence”) is long-term overfeeding and improper nutrition in general; that the only truly effective, causal drug in this case will be a fasting or semi-fasting diet, which in its various forms is also called fasting.Medicinal fasting has been known and used in medicine since ancient times and it was not until the 19th century that the rapid development of chemotherapy led to their abandonment, with the rapid spread of pharmaceutical drugs which, while removing only the symptoms, do not affect the very essence of the disease, yet often additionally poison the organism.