Assessment of dietary adequacy
Methods for evaluating dietary adequacy are described. This section simply draws attention to the limitations of these methods.
The first limitation is that the evaluation of nutri-ent intake can provide only an estimate of the risk of nutrient inadequacy for a population or an indivi-dual. None of the methods can identify the specific individuals who have a nutrient deficiency. Individu-als with a nutrient deficiency or excess can be identi-fied only on the basis of biochemical or clinical measures of nutritional status.
The second limitation is that all estimates of dietary adequacy/inadequacy obtained by compari-son with reference values for nutrient requirements depend on how the estimate is derived.
However, irrespective of the approach that is used to assess dietary adequacy, unless the extent of under-reporting is known and taken into account, the pro-portion of individuals at risk of inadequacy will be overestimated. While it may become possible to dis-tinguish more reliably in population-based studies valid from invalid reports of dietary intake, this still does not enable population-based estimates of inad-equacy to be made unless those who provide valid intakes are also representative of the population as a whole. All the evidence available to date suggests that this is highly unlikely.
When the principal objective of a dietary survey is to identify the proportion of the population who may have inadequate intakes of energy and nutrients, it is essential that the dietary intake information is inter-preted in the light of appropriate biological measures of nutritional status.