L12 - how good is this group's nutrient intake

Why is it important to collect information on group nutrient intake?

to monitor populations, identify problem nutrients for specific groups and plan programs to address problem nutrient e.g. supplementation or fortification

What is the EAR used for in groups?

to estimate the prevalence of inadequate intakes

What is the RDI used for in groups?

Dont use

What is the AI used for in groups?

mean usual intakes >this level indicates a low prevalence of inadequacy

What is the UL used for in groups?

estimate % age of population at risk of adverse effects

What is the first step to measuring nutrient adequacy in groups?

collect multiple days of dietary data through a diet record (2+ individual days or 3+ consecutive days) and 24 hour recalls (collect 2nd independent day in >50%)

What is the second step to measuring nutrient adequacy in groups?

adjust intake distribution - for day-day variability in intakes because if only 1 day of observations more people will appear to have consumption < EAR

What is the third step to measuring nutrient adequacy in groups?

use either the EAR cutpoint method of the full probability approach

What is the EAR cutpoint method and what does it assume?

shows prevalence of inadequacy as proportion of the population with intakes below the EAR, assumes no correlation between intakes and requirements, assumes variance of intakes > variance of requirements, assumes that distribution of intakes is symmetrical, assumes that prevalence of inadequacy is neither very high or very low (ideally 10-90%)

What is quadrant A?

people in quadrant A are false negatives as the method identifies them as fine because above the EAR however, their intake is inadequate for their individual requirements

What is quadrant B?

people in quadrant B are false positives because the method identifies them as inadequate because their intake is below the EAR however, their intake is adequate for their individual requirements

Why does the EAR cutpoint method work?

the number of false negatives and false positives cancel each other out so can estimate prevalence of inadequacy in group

What is the probability approach, what does it assume, and when must it be used?

shows prevalence of inadequacy as as probability of weighted average of risks at each intake level, assumes no correlation between intakes and must be used for Fe in premenopausal people or if prevalence of inadequate intakes is very high or very low in population

What are the steps in the probability approach?

construct a risk curve to give probability for each intake level that is inadequate, determine % of intakes in each category, determine prevalence of inadequacy: sum of(prob inadequacy x %intake in each category)

How is AI used for groups and what does it assume?

mean intake >AI → prevalence of inadequacy probably low, mean intake <AI → can’t determine adequacy, assumes that AI is based off a healthy and similar population to this group

How is UL used for groups?

similar to the EAR cutpoint method, must use appropriate intake distribution

What are the limitations of the EAR cutpoint method and full probability approach?

cant identify specific people in group with inadequate intake, dont have an EAR for all nutrients, and full probability approach is time consuming

What shouldn;t you do when using these methods?

compare mean group intake to the EAR or RDI, don’t use EAR cutpoint method for small groups<30