Book excerpt: Intermittent Fasting for Longevity and Performance Your cells are constantly monitoring the nutrient status of the cells to determine whether or not to conserve energy or to promote growth. **One of the few known ways of increasing lifespan in almost all species is caloric restriction and energy deprivation.** This triggers many metabolic pathways and processes that make the organism more adaptable to environmental stressors and thus live longer. **The metabolism has two sub-categories or sub-processes called anabolism and catabolism. ** * Anabolism, meaning 'upward' in Greek, describes the synthesis of biological molecules to build up new physical matter in the body. * Catabolism, meaning 'downward' in Greek, describes the breaking down of biological molecules to release energy. This can apply to the breakdown of bodily tissue as well as the digestion of food that then gets assimilated into the body through anabolic processes. In addition to 'Metabolic', you can also find another word in the title - 'Autophagy', which translates from Ancient Greek into 'self-devouring' or 'eating of self'. This is central to the main practice of this book. By maintaining a balance between anabolism and catabolism, you can effectively extend your lifespan. The process of autophagy entails your healthy cells devouring the old, worn-out, weak ones and converting them back into energy. It's literally your body eating itself and using that to maintain homeostasis. There are many longevity-boosting benefits to this as illustrated in virtually all other species. This book is a collection of guidelines about the principles of the anabolic-catabolic cycles in regards to nutrition and exercise. It's definitely not a panacea - a solution or remedy for all conditions and circumstances. Instead, it's a very specific protocol that's not supposed to apply for all situations. **Metabolic Autophagy will teach you:** * What increases lifespan in humans and other species * Why there's so much disease and obesity in society * How to promote health and longevity with intermittent fasting * What is Autophagy and how it works * How to age slower and be vigorous throughout your life * Which foods make you live longer and build muscle * How the nutrient regulators of mTOR, AMPK, sirtuins, FOXO proteins, hormesis and others affect longevity * What are circadian rhythms and how they affect your health * Metabolic Autophagy Foods list and their anabolic-catabolic score * Supplements that support muscle growth and longevity * Many extras and bonuses in regards to food and exerciseSiim Land is a best-selling author, anthropologist, entrepreneur, high-performance coach and a biohacker who writes about optimizing health and human performance.This book incorporates daily lifestyle and dietary practices that help to cross the chasm between longevity and high performance.