Nutritional assessment, apart from identifying what is essential as a good diet, can also be used in calculating individual needs. An example of this is the amounts of specific nutrients required by an individual; like for instance, the measurement of nitrogen balance. This is a very complex calculation, which is analyzed during the construction of the food tables and the sorting out of the nutritional status of an individual. During this specific calculation and research, different aspects must be taken into consideration.
There is first of all the range of foods covered by the tables. The food tables do not cover everything and involve some substitutes outside of its list. These alternatives have to be assessed and judged in order to evaluate whether it provides what is needed or not. One example is the kiwi fruit, which was not listed before. It has only previously joined the list as it is more common now.
The second point to be considered is the recipe variations. What I mean is that a particular and precise recipe cannot be obtained every time. Someone can cook the same meal over and over again but the taste varies as sometimes there is less or more of some ingredients involved in the cooking. The range, the ratio, the consistency differs every time and there always is that persisting slight variation.
My third point is the biological variation. An example can be an apple; the amount of vitamin C varies according to the different varieties. Another example is meat; the quantity of fat varies due to the region and manner the cattle are bred. Food tables in the end offer just an average and thus cannot be considered for all cases.
My final point is the method and duration of storage. The nutrient content of foods change...