Nutrients

A nutrient is any substance contained in food which cannot be created in the body and the purpose of which is to provide energy, amino acids or elements that regulate the metabolism.

 

They can be classified as:

- Energy nutrients or macronutrients: proteins, carbohydrates and lipids.

- Non-energy-producing nutrients or micronutrients: vitamins and minerals.

All these nutrients, together with water and dietary fibre, make up, to a lesser or greater degree, the full range of foods that we eat.

 

The first three nutrients are called energy nutrients as they are able to oxidise in order to provide energy to the body. Vitamins and minerals do not provide energy. Their function is to regulate metabolic reactions, however, in some cases (for example calcium) they have a structural function.

In normal conditions, the main function of carbohydrates and fats is to serve as energy-providing substances. The former provide energy for immediate use (glucose) or in reserve (glycogen) while the latter offer sources of reserve energy. Proteins should fulfil their main function, which is to form and repair the structures of tissues, i.e. the plastic function or formation of tissues, and cannot be used as a source of energy.

 

This section describes the main characteristics of nutrients