a) Activity level : Nutritional requirements change as a person gets older, because the elderly use a lot of medication their absorption, excretion and utilization of nutrients can be affected. Growing children have different nutritional needs to that of adults. For example, a growing infant requires a higher intake of essential fatty acids than that of an adult. In the same way there are different nutrition requirements for young and old there are also very different requirements between the sexes. For example, a womans nutritional requirements can vary throughout her menstrual cycle, also a woman who is pregnant or breastfeeding has different nutritional requirement to that of one who is not. Nutritional requirement vary depending on whether someone is healthy or ill. As diseases are unique so are the nutritional requirements needed whilst that person is ill.

The same applies to psychological and emotional stress. When people are affected by stress their appetite is affected, this results in less intake of food which in turn results in less nutrients being absorbed.

A person activity level will affect their nutritional requirement. An athlete will need a different nutritional requirement to that of an office worker. Exercise improves metabolic efficiency in some people and increases nutrient requirement.

People may find that certain nutritional requirements are increase within their family. Genetics can play a part in an extra need for certain nutrients. Other factors such as using recreational drugs, smoking and drinking can affect nutrient requirements. Even beverages like Tea and Coffee can affect nutrient requirements; they