Nutrition covers a wide range of topics including food composition and how individuals ingest, digest, absorb, transport, utilise and excrete food substances. The study of nutrition must also consider the wider context of certain social, economic, cultural and psychological aspects of food and food consumption.
Nutrition is directly relevant to health because of its role in every process within the body. The nutrients an individual receives can have many different functions in many different processes. For example, fat plays an important role in the integrity of cell walls and is also a major component of our brains.