This scientific book explores in-depth the key aspects of human nutrition. The first chapter addresses the body’s fundamental energy needs, explaining the different sources of energy and the factors influencing their use. The next chapter focuses on essential nutrients, detailing their role and vital functions in the body. The third chapter examines the metabolic processes associated with the digestion and use of nutrients. Next, the evaluation of nutritional needs is discussed, presenting the tools and methods used to determine individual dietary requirements. The book also discusses dietary patterns and their impact on health, with an emphasis on disease prevention. Chapter six delves into the relationship between nutrition and diseases, while the seventh explores global nutrition challenges. Finally, the last chapter looks ahead to the future of nutrition, addressing innovations and upcoming challenges.