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

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with the overall nutrient policy.
As an estimate of the between-individual variation,
the standard deviation of the ANR (SD ANR ) is
important in developing an INL. If the variation in
requirements is small, then an INL that is set at 1.5, 2,
or 2.5 SD ANR above the ANR will be relatively close to
the ANR; if the variation is broader, then the INL will
be larger. This demonstrates that the distribution of
requirements is an important determinant of the INL.
Two other NIVs, in addition to the INL x , may also be
derived. A ”deficient” or lower nutrient intake level may
be established at some point below the ANR (e.g., 2 SD
below) to serve as an estimated intake that is probably
below the needs of practically all individuals. Since the
ANR is usually used to estimate the proportion of the
population with inadequate intakes by determining
the percentage below the ANR [2, 17], a lower nutrient
intake level has limited use.
If information is available on the level of intake of
a specific nutrient that carries health risks, an upper
nutrient intake level (UNL) may also be established.
The UNL is usually set where the risk of excessive
intakes is very low, close to zero. The UNL is a level of
intake that should be avoided on a chronic basis [9].
There is no established benefit to consuming nutrient
intakes above the INL set at 2 or 2.5 SD ANR .
Estimating energy requirements
Energy recommendations are set at levels that represent
the average needs of individuals in the population. In
determining energy standards, factors such as age, sex,
and level of physical activity should be considered.
Energy standards may be expressed as equations that
permit the calculation of energy intake requirements
based on these factors.
It would not be appropriate to set an energy INL x as
was done for the other nutrients, because adding an
increment (e.g., 2 SD) to the average energy requirement
would result in an intake goal that would lead to
weight gain. If the energy intake is consistently above
or below the average requirement for a long enough
period of time, changes in body weight will occur
and may adversely affect health. As a consequence,
recommendations for energy are expressed in terms
of energy expenditure rather than energy intake in
order to prevent under- or overconsumption. Since
nutrient standards are set for healthy individuals, it is
assumed that body energy stores are appropriate and
that the average requirement should be used as the
standard for the entire population. Because energy
intake and expenditure are not independent, it is not
possible to determine the probability that energy intake
is adequate.
Acceptable macronutrient distribution
ranges
J. C. King et al.
Recently, several countries or regions have established
acceptable ranges for the percentage of energy coming
from carbohydrate, protein, and fat in the diet, which
are thought to reduce the risk of long-term or chronic
disease while providing an adequate intake of essential
nutrients. The term used to describe these recommendations
is acceptable macronutrient distribution range
(AMDR). The AMDR is expressed as a percentage of
total energy intake, because the range is not independent
of other fuel sources or of the energy requirement
of the individual. As mentioned earlier, definitions used
for macronutrient intakes as a percentage of energy
vary. The AMDRs established by the United States and
Canada refer to appropriate ranges of usual intakes of
individuals, whereas the WHO standards are population
mean intake goals [6, 22]. Thus, the WHO mean
intake goal of 15% to 30% of the energy as fat implies
that it is acceptable for half of the individuals in a
population to have intakes below 15%.
Although a range of protein intakes as a percentage
of energy has been established, since protein is one of
the fuel sources of the diet, there is also a specific minimum
need for nitrogen and amino acids that serves as
the basis for the protein ANR and INLx. Those values
are usually presented as grams or milligrams per day.
Since the need for nitrogen or amino acids is likely
to be independent of intake, the theoretical statistical
model can be used to estimate the probability of
inadequacy for an individual and the prevalence of
inadequate intakes in a population. When protein NIVs
are derived, the committees need to ensure that those
NIVs can be acquired within the range of acceptable
protein intakes.
General features of the statistical model for
estimating nutrient requirements
There are two important caveats associated with this
model for estimating nutrient intake values [31].
First, the estimates of requirements pertain to the
maintenance of health in already healthy individuals.
Such estimates may or may not pertain to individuals
with disease, and they certainly are inappropriate
for individuals recovering from nutrient deficiencies.
Second, nutrient intake refers to the usual intake of an
individual or group, i.e., the average intake for weeks
or months, not days.
The primary advantage of this general framework
is its simplicity. Only the midpoint of the requirement
distribution (the ANR) needs to be determined from
primary scientific data. Ideally, one would also like
information regarding the variance in the requirement
in a large, representative population. However,