Implementing food-based dietary guidelines for - United Nations ...

Terminology and framework for nutrient intake values
both “recommended” and “reference.”
In addition to an average and recommended (or
reference) nutrient intake value, recommendations
include a lower reference intake that defines a value
that is below the requirements of most individuals in
the population, an upper intake value that is the highest
intake unlikely to pose any health risks, a safe intake
value (or range) or adequate intake that is used when
the statistical distribution of requirements is unknown,
and a range of intakes for macronutrients (adequate
macronutrient distribution range [AMDR]) associated
with a reduced risk of chronic disease.
Proposed terminology for nutrient intake
values (NIVs)
To avoid confusion about the meaning of acronyms
and the use of multiple acronyms for the same nutrient
intake standard, we propose that a common set
of terms and definitions be used by all countries and
regions establishing NIVs. We recognize, however,
that the absolute values will probably differ among
the various countries and regions, because differences
in body size, the bioavailability of food sources, and
environmental conditions that affect nutrient needs
(e.g., sunshine exposure or altitude) will influence the
statistical distribution of nutrient requirements in a
particular population. Nevertheless, we believe that the
same terms and definitions can be used worldwide. The
following terms are recommended.
Average nutrient requirement (ANR)
The ANR is the average or median requirement estimated
from a statistical distribution of requirements
for a specific criterion and for a particular age- and
sex-specific group.
Individual nutrient level x (INL x )
The INL x is the recommended nutrient level for all
healthy individuals in a specific subpopulation. Often
committees add 2 SD to ANR, which will cover the
needs of most (i.e., 98%) of the population, assuming
that the distribution is symmetrical. In that case, the
INL x would be INL 98 . But one might choose a lower
level in the distribution of requirements for the recommended
intake if the current nutrient policies of the
country or region conclude that it is not practical to
achieve an intake equal to the 98th percentile for the
entire population. This might be the case, for example,
if the additional cost of providing fish rich in omega-3
fatty acids is inconsistent with the food supply for a
country. Then one might choose to make a recommendation
at a lower level, such as 1.5 SD above the
ANR, or at the 93rd percentile. In that case, the INL 93
S21
would meet the needs of 93% of the population. Thus,
the INL x for a specific country or region should be
consistent with the overall nutrition policy.
Upper nutrient level (UNL)
The UNL is the highest level of daily nutrient intake
that is likely to pose no risk of adverse health effects
for almost all individuals in a specified life-stage group.
Ideally, it is based on an analysis of the statistical distribution
of risk for high nutrient intakes. The UNL is
usually set at a level where the risk of excessive intakes
is close to zero. Also, the UNL is a level of intake that
should be avoided on a chronic basis [9].
General framework for estimating nutrient
intake values (NIVs)
Starting with the report by the United Kingdom recommending
a multiple reference framework for quantitative
nutrient standards [10] and the subsequent reports
of the US/Canadian dietary reference intakes (DRIs)
[3–7], a new statistical approach was used for making
dietary recommendations. The general features of this
model were adopted by a number of other countries or
regions, such as the Germanic language nutrition societies
[15], South Korea [13], Southeast Asia [14], and
Australia and New Zealand [16], as well as WHO/FAO
[23]. The framework for assessing intakes of population
groups stems from the work of a subcommittee of
the US Food and Nutrition Board [25] that related the
probability of inadequacy to nutrient requirements.
The framework has since been expanded to include
both assessment and planning of nutrient intakes and
can now be applied to both individuals and groups
[17, 26].
Determining the average nutrient requirement
The first step in estimating nutrient requirements is
to determine the average nutrient requirement (ANR)
for a defined population from primary research data
(fig. 1). Once the distribution of requirements is
known, the ANR can be estimated. Often the ANR
for a population is estimated from experimental data
derived from a subsample of individuals in the defined
group, because in practice, rarely, if ever, are the specific
nutrient requirements known for each person in
a group of interest. However, it is usually not possible
to mirror completely the diversity of the group. For
most nutrients, data on individual responses to varying
levels of nutrient intake are scant, resulting in the
need to make many assumptions about the attributes of
the population group from data obtained from a small
subsample that has been studied in depth. With each
assumption, there is potential error and a decrease in