In this book, Weston A. Price documents his nearly 10-year global journey to understand the secret to health. He focused on healthy individuals in isolated primitive cultures and observed their excellent health, including perfect dental arches, minimal tooth decay, and high immunity to diseases. Price found that when these populations adopted modernized foods such as white flour, white sugar, and refined oils, they quickly showed signs of degeneration, including dental caries, deformed jaw structures, and increased susceptibility to chronic diseases. The book includes hundreds of photos and detailed analyses of the nutritional content of indigenous foods versus modern diets, emphasizing the critical role of fat-soluble vitamins and minerals in maintaining health.