Human nutrition, thus, represents the process by which the substances being ingested in foods are metabolized into body tissues and energy for the various activities in human life. Nutrition is a branch of biology that focuses on human nutrition and is complex, as it encompasses not only physiology, biochemistry, and molecular biology but also psychology and anthropology which investigates people's attitudes, beliefs, preferences, and practices.

Human nutrition also discusses the economic and political aspects, since humanity acknowledges and reacts to hunger and death from malnutrition. The main aims of nutritional science are to achieve improved health and minimal risk of several such diseases as cardiovascular disease and cancer, and the exclusion of usual nutritional deficiency diseases such as kwashiorkor and pellagra.

Due to the multi-disciplinary accumulation of nutrition sciences, comprehending human nutrition is based on many aspects. Nutrition scientists analyze how diet components are metabolized in people’s organisms, while behaviorists and anthropologists focus on how people’s actions and cultures define their dietary habits. Economists and political scientists investigate matters relating to food and nutritional security, dependent on socioeconomic and political systems.

The practice of nutrition aims to enhance the health of a particular population by ensuring that a population receives the recommended portions of nutrients in every given period. This consists of protein, carbohydrates, fats, vitamins, and mineral requirements of the body. In this case, people will be in a position to control their health by feeding on a balanced diet, sharpening their immune system, and reducing the likelihood of growing persistent ailments in their bodies.