This section looks at definitions and different ways of describing food intake and diet.

Nutrition is the science of how we take in and use food in the body. Food is defined as ‘any solids or liquid which can be swallowed and supply material from which the body can produce movement, heat or other forms of energy, material for growth and repair or reproduction or substances necessary to regulate the production of energy or the processes of growth and repair’ (MAFF 1995 ). All foods have components, known as nutrients.

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Nutrients consist of carbohydrates necessary for energy and which may be turned into body fat; fats which provide energy, protect vital organs and also help the absorption of certain vitamins; proteins which are essential for growth and repair of the body; minerals and vitamins which regulate the body’s processes and some of which are also used for growth and repair. Water is also essential for health although it is not defined as or considered to be a nutrient. Fibre is also not considered a nutrient as the body does not absorb it, but it is needed for healthy bowels.

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How we eat this mixture of food is known as our diet. A good diet provides all our nutritional requirements from a broad range of foods. Sometimes substances are added to food to perform specific functions. These are known as additives. Additives maybe used to prevent food spoilage or enhance the texture, flavour or appearance of food. Malnutrition is the result of a long period of time with insufficient amounts of nutrients. This could be from inadequate amounts of specific nutrients or lack of a combination of nutrients.