The author argues that human beings are naturally frugivorous, advocating a diet centered on fruit and nuts, supported by comparative anatomy, physiology, chemistry, hygiene, and empirical observation. The book examines nutritional constituents—proteins, fats, carbohydrates, and minerals—reviews dairy, vegetables, cereals, condiments, and food combinations, and presents hygienic cookery and guidance on quantities. It contrasts national and individual dietary experiences, supplies tables of food composition, and advances practical recommendations for economical, health-preserving eating intended to maintain vitality and prevent disease.