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
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.