Lecture 11 - How Good is a Persons Nutrient Intake Flashcards
4 steps to nutritional assessment
- anthropometric assessment
- dietary assessment
- biochemical assessment
- clinical assessment
dietary assessment alone is
not enough to work out someones nutritional status
what is the appropriate use of the EAR (individuals)
use to examine probability that usual intake is inadequate
what is the appropriate use of the RDI (individuals)
usual intake > this level has low probability of inadequacy (not so good for use for individual)
what is the appropriate use of the AI (individuals)
usual intake > this level has a low probability of inadequacy
what is the appropriate use of the UL (individuals)
usual intake > this level may place an individual at risk of adverse health affects
for nutrient adequacy in individuals, in an ideal world you would compare ….. BUT
- individuals long term usual intake
- individuals requirement
but we dont know either so
- individuals observed intake
- best guess at their requirement = EAR
we dont know individuals long term intake of requirement which means we can only get their ….. and what is this
apparent adequacy
- “an estimate of the confidence one has that usual intake is above (or below) an individuals requirement”
what are the 3 steps to the quantitative approach for nutrient adequacy in individuals
- obtain info on indivuals usual intake
- choose an appropriate reference standard
- determine apparent adequacy
what is step one in the quantitative approach for nutrient adequacy in individuals
obtain info in individuals usual intakes
- calculate individuals mean intake
- find an estimate of day to day variation in intakes (ideally national data - e.g IOM tables
what is step two in the quantitative approach for nutrient adequacy in individuals
choose an appropriate reference standard
- EAR = best guess of individuals actual requirement
- RDI = not recommended, dont know the individuals usual intake
- AI = can use if thats all you’ve got
what are the 3 equations used to determine apparent adequacy (quantitative approach for nutrient adequacy - individuals) = using EAR example (ideal), and what should we do with this answer
D = y - r
SD(D) = square root of (Vreq + (Vwithin /n))
D / SD(D) =
compare this answer to IOM table to determine probability of correctly concluding that usual intake is adequate or inadequate
what does D mean in the 3 equations used to determine apparent adequacy (quantitative approach for nutrient adequacy - individuals) = using EAR example (ideal)
difference
what does SD(D) mean in the 3 equations used to determine apparent adequacy (quantitative approach for nutrient adequacy - individuals) = using EAR example (ideal)
SD of difference
what does Vreq mean in the 3 equations used to determine apparent adequacy (quantitative approach for nutrient adequacy - individuals) = using EAR example (ideal)
variance of distribution of reqs in group
what does Vwithin/ n mean in the 3 equations used to determine apparent adequacy (quantitative approach for nutrient adequacy - individuals) = using EAR example (ideal)
average variance in day - to day intakes of nutrient
when using the AI for individuals - quantitative approach for determining nutrient adequacy it is a similar
approach to EAR but can only determine the certainty that intake is > AI
when using the AI for individuals - quantitative approach for determining nutrient adequacy it can not tell
can not tell u about anything about adequacy of intakes < AI
AI is often higher than what and
higher than the RDI, there is no information on its distribution
the quantitative approach for individuals assumes
- requirements are normally distributed, BUT no for Fe premenopausal women
- intakes are normally distributed, BUT not for vitamins A, B12, C, E
when using the EAR if observed intake is < EAR
probably need to increase (Padeq<50%)
when using the EAR, if EAR < observed intake < RDI
probably needs to increase
when using the EAR if long term observed intake is > RDI
probably adequate
when using the AI is long term observed intake is > AI
probably adequate
when using AI if observed intake is < AI
we can’t determine adequacy
when using the UL if the observed intake is > UL
potential risk if over many days
when using the UL if the observed intake is < UL
probably safe is over many days
what are the limitations for methods determining individual adequacy
- dont have usual intake or actual requirement
- assume CV of 10% for SDreq
- assume SDintake for individual similar to pooled data from CSFII
- assume no low energy reporting
- dont have EAR for all nutrients
need other nutritional assessment data as well
the NRVs are used to determine the probability that
an individuals intake meets their own requirement
the quantitative approach ideally
uses the EAR and can be used for most nutrients
similar approaches can be used for the
UL and AI for individuals
the qualitative approach provides
much less information but has to be used for some nutrients
what does y equal in the quantitative approach using the EAR
D = y - r
y = mean observed intake for individual
what does r equal in the quantitative approach using the EAR
D = y - r
median requirement (EAR)
what does everything mean in the equation SDD = square root of Vreq + ( Vwithin / n ))
SDD = SD of difference
Vreq = variance of distribution of reqs in group
Vwithin = average variance in day to day intakes of nutrient
n = number of days intake observed
