In 2005, the author's The China Study showed that a diet based on whole, plant-based foods dramatically reduces the risk of a broad spectrum of diseases, including heart disease, obesity, diabetes, and cancer. It revealed what we should eat and provided the powerful empirical support for this answer. This new book picks up where the previous one left off. It answers the question of why. Why does a whole-food, plant-based diet provide optimal nutrition? It demonstrates how far the scientific reductionism of the nutrition orthodoxy has gotten off track and reveals the elegant wonders of the true holistic workings of nutrition, from the cellular level to the operation of the entire organism. This is a journey through cutting-edge thinking on nutrition with implications for our health.