Midterm 3 (Lecture 11

Question 1

DRI: traditional recommendations

Answer 1

Set of standards for energy and nutrients
Canada:RNI (recommended nutrient intakes)(never revised)
USA: RDA (Recommended dietary allowances) ( revised every four years)

Goal is to prevent nutrient deficiencies

Question 2

DRI: overall structure

Answer 2

Standing committee in the scientific evaluation of dietary reference intakes
- subcommittee: upper reference levels of nutrients
- subcommittee: interpretation and uses of DRIs

These committees facilitated the development and publication of DRI reports for individual nutrients

Question 3

DRI organizations involved

Answer 3

Standing committee on the scientific evaluation of dietary reference intakes
- subcommittee: upper reference levels of nutrients
- subcommittee: interpretation and use of DRIs

expert nutrient review panels

Organizations involved:
- food and nutrition board (FNB) of the institute of medicine (IOM), part of the National Academy of Sciences (NAS)
- Health Canada

Question 4

Dietary reference intakes: what are they?

Answer 4

Consists of four reference values: EAR, RDA, AI, UL

Quantitative estimates of nutrient intakes

Consider more than just preventing deficiency

Used for planning and assessing diets of healthy individuals and groups

Question 5

Why change DRIs?

Answer 5

Want to optimize health

Expanded knowledge regarding the role of nutrients in prevention of chronic disease

Extend goal of recommendations beyond preventing deficiencies

Incorporate chronic disease, not just deficiency into deciding the values

Harmonize Canada and USA

Question 6

How are the DRIs different

Answer 6

Health maintenance and risk reduction
Four versus one??
US and Canada
Will no longer be reviewed every X number of years
If new evidence warrants, DRIs for individual nutrients will be revised

Example of vitamin C
- potential criteria of adequacy: prevent scurvy, saturate tissues, maximize absorption of non heme iron
- reduce risk of gastric cancer

Question 7

Estimated average requirement (EAR)

Answer 7

A daily nutrient intake value that is estimated to meet the requirement of half of the healthy individuals in a particular life stage and gender group

Question 8

EAR: what is the point

Answer 8

Amount that meets 50% of individuals in a particular life stage,gender group

Used in nutrition policy

Used for PLANNING: how much a GROUP needs

Used for ASSESSMENT: adequacy of nutrient intakes of a GROUP AND/OR INDIVIDUAL

Question 9

Recommended dietary allowance (RDA)

Answer 9

The average daily dietary intake level that is sufficient to meet the nutrient requirement of nearly all (97.5%)of healthy individuals in a particular life stage and gender group

Question 10

RDA: what does it mean

Answer 10

EAR plus two standard deviations

Normal distribution: 68-95-97.5 % rule for normal distributions

Used for PLANNING for INDIVIDUALS
- aim for the RDA

Different from previous RDA/RNI that different criteria of adequacy are used

Intake over time - day to day variation expected ted

Question 11

Adequate intake (AI)

Answer 11

A recommended daily intake value based on observed or experimentally determined approximations of nutrient intake by a group of healthy people - used when the EAR and RDA cannot be determined

Question 12

AI: what does it really mean

Answer 12

Created when there isn’t enough evidence to calculate an EAR and subsequent RDA

Obtained from data that show a mean intake that appears to sustain a desired indicator of health (eg,calcium retention in bone)

Used for PLANNING: for INDIVIDUALS when RDA doesn’t exist, for GROUP when EAR doesn’t exist

Used for ASSESSMENT: for INDIVIDUALS when an EAR doesn’t exist, for GROUP when an EAR doesn’t exist

Has limitations, not accurate as the EAR for assessment

Question 13

Tolerable upper intake level (UL)

Answer 13

The highest level of daily nutrient intake that is likely to pose no risk of adverse health effects to almost all individuals in the general population. As intake increases about the UL, the risk of adverse effects increases

Question 14

UL: what does it really mean

Answer 14

Guards against over consumption

NOT a recommended level of intake

Useful due to increased use of supplements and increased availability of fortified foods

Based on total intake from food, fortified food and supplements

Can be used for planning and assessment

Question 15

DRIs vary by life stage group

Answer 15

Specific values for life stage groups like: infants, children, males/females, pregnancy/lactation

Various age cutoffs as well

Note that infants usually assigned an AI “bc we have less info” - number comes from how much breast milk is consumed

Question 16

DRI comments

Answer 16

Everyone is different

Values are set accounting for this variation

Used for planning and assessment

Note that people eat food not nutrients
- DRIs can be helpful as guidelines for individuals
- healthy eating is best planned using canadas food guide to healthy eating

Question 17

DRI: review of the issues

Answer 17

Estimates apply to healthy people

Estimates reflect usual daily intakes
- need to account for variability somehow

Each DRI reference number serves a unique purpose
- EAR then RDA
- AI is set when there’s no EAR
- UL

all used in planning and assessments of groups or individuals

Subject to review as evidence evolves

Question 18

DRI report released in 2000

Answer 18

DRIs: Applications in dietary assessment

Key guide to actually using DRIs

What each number is used for, individuals vs groups

Which values for individuals and which for groups?

Question 19

Implementation of DRIs in Canada

Answer 19

HC assembles expert advisory panels

Review DRIs and identify public health implications in Canada

Public policy , public programs, public educations

Links between DRI and canadas dietary guidelines

Question 20

Others

Answer 20

Table

Graph

Last two slides DRI