Nora Gedgaudas shows how our modern grain- and carbohydrate- heavy low-fat diets are a far cry from the high-fat, moderate-protein hunter-gatherer diets we are genetically programmed for, leading not only to lifelong weight gain but also to cravings, mood disorders, cognitive problems, and "diseases of civilization" - such as cancer, osteoporosis, metabolic syndrome (insulin resistance), heart disease, and mental illness. Applying modern discoveries to the basic hunter-gatherer diet, she culls from vast research in evolutionary physiology, biochemistry, metabolism, nutrition, and chronic and degenerative disease to unveil a holistic lifestyle for true mind-body health and longevity. Revealing the primal origins and physiological basis for a high-fat, moderate-protein, starch-free diet and the importance of adequate omega-3 intake - critical to our brain and nervous system but sorely lacking in most people's diets - she explains the nutritional problems of grains, gluten, soy, dairy, and starchy vegetables; which natural fats promote health and which (such as canola oil) harm it; the crucial role of vitamin D in cancer and disease prevention; the importance of saturated fat and cholesterol; and how diet affects mental health, memory, cognitive function, hormonal balance, and cellular aging. With step-by-step guidelines, recipes, and meal recommendations, this book offers sustainable strategies for a primally based, yet modern approach to diet and exercise to reduce stress and anxiety, lose weight, improve sleep and mood, increase energy and immunity, enhance brain function, save money on groceries, and live longer and happier.