1) DRI Flashcards
1
Q
What are DRIs?
A
New references for planning and assessing nutrient intakes
2
Q
When were DRIs developed? Who developed DRIs?
A
- In 1997
- Joint collaboration between Health & Welfare Canada, USDA, NIH, and the US Academy of Sciences (FNB of IOM)
3
Q
What was the issue with the Recommended Daily Allowance (old RDA)?
A
- Issued a false impression that the recommendation must be met every single day, and that a state of deficiency would occur if not
- The body stores certain nutrients, which may compensate if an individual does not consume an adequate amount in a day
4
Q
What do the DRIs expand and replace?
A
- The former RDAs in the US (published since 1941)
- The Recommended Nutrient Intakes (RNIs) in Canada (published since 1938)
5
Q
What was the RNI previously referred as?
A
The Recommended Daily Nutrient Intake (RDNI), which was changed in 1983 to reflect an average intake over time
6
Q
What are the components of the committees regulating DRIs?
A
- Standing Committee on the Scientific Evaluation of DRIs
- Nutrient Expert Panels
- Upper Reference Level Subcommittee
- Uses of DRIs Subcommittee
7
Q
What are the functions of the Standing Committee on the Scientific Evaluation of DRIs?
A
- Oversees the five-year process, coordinating the recommendations from nutrient panels and subcommittees
- Submits the report for review to the National Research Council
8
Q
What is the major function of Nutrient Expert Panels?
A
Develop a series of DRI reports, in conjunction with the two subcommittes
9
Q
What five factors do Nutrient Expert Panels analyze?
A
1) The role the nutrient plays in each life stage
2) The role the nutrient plays in the development of chronic disease
3) The indicator of adequacy of the nutrient
4) The EAR of the nutrient for each life stage
5) The interpretation of the current intake data of North American population groups
10
Q
How many Nutrient Expert Panels are there?
A
7
11
Q
What is the mandate of Nutrient Expert Panels?
A
To determine nutrient requirements for the prevention of nutrient deficiencies AND to consider the levels of intake needed to prevent chronic disease
12
Q
Why is the Upper Reference Level Subcommittee particularly important in recent years?
A
Since supplementation and food fortification are now a major source of nutrition
13
Q
What two factors does the Upper Reference Level Subcommittee analyze?
A
1) Hazard identification to determine the highest intake of a nutrient without adverse effects
2) Assessment of the actual exposure of the population to determine to what extent there is a risk for toxicity
14
Q
What is the major function of the Uses of DRIs Subcommittee?
A
- Deals with appropriate (or inappropriate) applications for reference intakes
- Overall, they help the population interpret and apply the information
15
Q
What is a nutrient?
A
Substance that is necessary for proper biological and physiological function, without which deficiency occurs
16
Q
What are other food components?
A
Foods that are not considered nutrients (e.g. phytochemicals)
17
Q
What is the difficulty with applying recommendations for other food components?
A
The fact that there are no nutrient composition tables
18
Q
What are the four nutrient-based references of DRIs?
A
- EAR
- RDA
- AI
- UL
19
Q
What do DRIs focus on?
A
Chronic disease prevention
20
Q
How is chronic disease prevention taken further from DRIs? (4)
A
1) Looking at RDA values for micronutrients
2) Recommendations are set for deficiency, disease prevention, and chronic disease prevention
3) UL is established due to the common use of nutritional supplements
4) Non-essential food components are being considered for chronic disease prevention
21
Q
What population groups do RDAs not apply to?
A
- They do not apply to individuals with specific illnesses
- RDAs are generated as recommendations for a healthy population
22
Q
What percentage of the population is met with an EAR + 1 standard deviation? What about an EAR + 2 standard deviations?
A
- EAR: 50%
- EAR + 1SD: 84%
- EAR + 2SD: 97.5%
23
Q
Which DRI is used for groups? Which DRI is used for individuals?
A
- EAR: groups
- RDA: individuals
24
Q
How is the EAR determined?
A
The intake of the nutrient that provides adequate intake for 50% of individuals in a life stage and gender group
25
What factors are added to the intake of a nutrient that provides adequate intake for 50% of individuals to produce the EAR?
- Safety factor for optimal tissue stores
- Factor that accounts for accounts for additional needs for growth (e.g. pregnancy, lactation, childhood)
- Factor for bioavailability (if the nutrient has less than 100% absorption)
26
In addition to usual intake distribution of healthy people, valid studies must be considered concerning what? (3)
- Deficiency states
- Balance studies
- Animal research
27
What are the four conceptual similarities between DRIs and the former RDAs and RNIs?
They must account for:
1) Individual variability in a population
2) Bioavailability
3) Sex and age differences
4) Physiological state (e.g. pregnancy and lactation)
28
What curve would a population with a highly variable requirement produce? How would the RDA differ from the EAR?
- A flatter curve with a high standard deviation
| - The RDA would be much higher than the EAR
29
What are the four criteria of adequacy?
1) Biomarkers of exposure
2) Biomarkers of mechanisms or functional outcome
3) Biomarkers of effect
4) Biomarkers of a clinical outcome
30
What are examples of biomarkers of exposure?
- Blood levels
- Balance studies
- Pool saturation (e.g. hemoglobin saturation)
31
What are examples of mechanisms or functional outcome?
- Enzyme saturation
| - Enzyme activity
32
What are biomarkers of effect? What are examples of biomarkers of effect?
- Analysis of the efficacy outcome, which indicates if there is a risk for a clinical outcome
- Bone mineral density, LDL levels
33
What are examples of a clinical outcome?
Symptomatic state (e.g. osteoporosis, dental caries)
34
What is the EAR?
The usual intake that is estimated to meet the requirement of half (50%) of healthy individuals in a life stage and gender group
35
Is the EAR based on the average intake of a group?
NO, it is based on the intake distribution of the group
36
What criterion of adequacy is the EAR for vitamin C based on?
An amount thought to provide antioxidant protection as derived from the correlation of such protection with neutrophil ascorbate concentrations
37
What is the major difference between the RDA and the former RDAs and RNIs?
The RDA is determined QUANTITATIVELY through the EAR, rather than through judgment-based safety factor
38
What is the equation used to determine the RDA if the standard deviation of the EAR is available?
RDA = EAR + 2SD
39
If the SD of the EAR is not available, what is the coefficient of variation assumed to be?
10%
40
What is the equation used to determine the RDA if the standard deviation of the EAR is not available?
RDA = EAR(1.2)
41
How are energy requirements estimated? What factors are utilized?
- Estimated on an individual basis
| - Using sex, age, height, weight, and physical activity level
42
What is the criterion of adequacy in the estimation of energy requirements?
A healthy BMI and healthy level of physical activity
43
What is used as the standard for the estimation of energy requirements?
The mean intakes of an adequately nourished population, as it is assumed that for energy there is a high correlation between intake and expenditure so that energy balance is closely maintained
44
Why aren't nutrient-based RDAs used for energy?
As setting higher intakes increases the risk of overconsumption of energy, and subsequent obesity
45
How do RDAs participate in the assessment of risk of deficiency for an individual?
- RDAs allow an estimate of probable risk of deficiency for an individual if the diet is assessed over time
- The intake below the RDA cannot indicate a nutritional deficiency with certainty
46
What factors are analyzed to determine nutritional status?
- Anthropometrics
- Biochemical
- Clinical
- Dietary
- Functional
47
What is the established cut-off for the RDA that determine a high probability for deficiency?
- 2/3 below the RDA
| - However, this does not guarantee that the individual is at risk, as perhaps they simply require a lower requirement
48
How is the RDA intended to be met and achieved?
- Through diets containing a variety of food
| - Achieved via average daily intakes over a period of days
49
What factors do NOT influence the development of the RDA? (2)
- To overcome nutrient deficiencies
| - To recover from illness
50
Which factor USED to not influence the development of the RDA?
Prevention of chronic disease
51
Which nutrient demonstrates a high-variability of intake? Which nutrients demonstrate a low-variability of intake?
- High-variability: vitamin A
| - Low-variability: protein, vitamin B6
52
The period of time needed to compensate for a deficient intake depends on what factors? (2)
- Body pool size
| - Nutrient turnover
53
How does a high body pool size influence the period of time needed to compensate for a deficient intake?
Allows the body to readily compensate in periods of low intake by depleting nutrient stores (e.g. vitamin A, vitamin B12)
54
How does slow nutrient turnover influence the period of time needed to compensate for a deficient intake?
Uses very few amounts of the nutrient from bodily stores every day, prolonging the time for deficiency to occur in periods of low intake (e.g. vitamin B12)
55
How does small pool size and rapid nutrient turnover influence the period of time needed to compensate for a deficient intake?
Signs of deficiency are observed more rapidly (e.g. over 3 days with vitamin B2)
56
Which population groups do not have the same protection as adults in periods of deficient intake? Why?
- Children and infants
| - They have time with a prolonged intake of a certain nutrient to maintain these body stores, as adults would
57
Why isn't comparing the mean intake of a group with the EAR a good approach?
- Group A and B may possess the same mean intake, but their intakes may be more variable
- The prevalence of inadequacy is higher in the group with the greater variability in intake
58
What factors are combined when planning nutrient intake within a group?
- Nutrient requirements (requirement distribution with the EAR)
- Nutrient intake (intake distribution)
- The EAR and the variability of the intake of the group is used to set the target intake
59
Why isn't a lower prevalence of deficient intakes (e.g. 0.1%) targeted with the RDA?
Because it causes most individuals to have intakes that are much greater (possibly, excessive and toxic) to their actual needs
60
What are the four conceptual differences between DRIs and the former RDAs and RNIs?
1) When possible, the reduction in the risk of chronic degenerative disease is included in the formation of the RDA
2) Concepts of probability and risk explicitly underpin the determination of the DRIs
3) Upper levels of intake are established
4) Food components that may not meet the traditional concept of a nutrient are considered
61
What was the main criticism of the former RDAs and RNIs?
They were based on insufficient information, as there were no metabolic studies to estimate their recommendations
62
What was used to determine the former RDAs and RNIs?
- The mean intakes of a healthy population, lacking signs of deficiencies
- This may not reflect the actual requirement of a person or of a group of people
63
What is the AI?
Used instead of the RDA when an EAR cannot be calculated due to insufficient information
64
What are the four areas of criticism of the RNI?
1) Indices of nutritional adequacy were sometimes based upon insufficient information
2) Group mean intakes were used as the standard for nutritional adequacy
3) If not associated with nutritional deficiencies, they could be used as valid indices for setting the RNI
4) These mean values do not incorporate the 2SD from the mean safety factor
65
What is the AI based on? (2)
1) Observed or experimentally determined approximations
| 2) Estimates of nutrient intake by a group (or groups) of healthy people that are assumed to be adequate
66
What does an individual's intake ≥ AI indicate?
That the diet is almost certainly adequate (low prevalence of adequate intake)
67
How can you determine the proportion of deficient individuals consuming ≥ AI?
The proportion of deficient individuals consuming ≥ AI CANNOT be determined
68
What does an individual's intake ≤ AI indicate?
- Individuals consuming ≤ AI cannot be referred to as having inadequate intakes
- There is no quantitative (or qualitative) estimate that can be made of the probability of nutrient adequacy, as the point where risk increases cannot be determined
69
Which DRI is an intake? Which DRI is a requirement?
- AI: intake
| - RDA: requirement
70
What is the UL?
The highest average daily nutrient intake level likely to pose no risk of adverse health effects for almost all individuals in the general population
71
What occurs as intake increases above the UL? How does that benefit the individual?
- The potential risk for toxicity and adverse effects increases
- There are NO established benefits of intake above the RDA or AI
72
The UL refers to the total intake from what sources?
- Food
- Fortified food
- Nutritional supplements
- Water intake (i.e. hard water)
- For certain nutrients, the UL solely refers to the intake from nutritional supplements
73
What cannot be assumed if there is no UL for a nutrient?
It does not mean that intake at any level is without risk, but that the safe upper level is undetermined
74
What is the risk of deficiency at the EAR?
50%
75
What is the risk of deficiency at the RDA?
2.5%
76
How is the AI related to the EAR and RDA?
There is no consistent relationship to the EAR and RDA, as it is set without the estimation of the actual requirement
77
What occurs if the intake is between the RDA and the UL?
The risks of inadequacy and adverse effects are close to 0
78
What occurs if the intake is above the UL?
The risk of adverse effects increases
79
How is the AI used in infants?
As the appropriate index for the requirements of all nutrients up to one year of age, as there is insufficient data to calculate an EAR and RDA
80
Why is adulthood divided into fewer categories than infancy to adolescence?
- Because nutrient requirements are extremely important for growth
- The categories in adulthood reflect less drastic changes in requirements than childhood and adolescence
81
What are dietary guidelines? What are they derived from?
- Refer to optimal proportions of energy-yielding macronutrients
- Derived of RDAs
82
What do dietary guidelines describe? What don't they describe?
- Describe food components
| - Don't describe nutrients
83
How do dietary guidelines differ from the RDA?
- RDAs express the weight of nutrients to be consumed
- Dietary guidelines provide semi-quantitative advice on the consumption of a food component (e.g. percentages of total energy)
- Dietary guidelines can also be targeted to improve behavior towards a future goal for the population
- Dietary guidelines are the same for all age groups, genders, and life stages
- RDAs separate numbers for males and females of different age categories
84
What is the function of the Food Guide?
Translates nutrient requirements and health impacts of food intake into a practical pattern of food choices
85
Define health, according to the Food Guide.
Social, mental, and physical well-being
86
Who is the Food Guide intended to aid?
Canadians two years of age and older
87
What pattern of eating does Canada's Food Guide describe? (4)
- Is sufficient to meet nutrient needs
- Contributes to a reduced risk of nutrition-related health problems
- Supports the achievement and maintenance of a healthy body weight
- Reflects the diversity of foods available to Canadians
88
What were the areas of focus when Canada's Food Guide was revised from 2002 to 2007? (4)
1) Nutrient targets
2) Energy levels
3) Food groups
4) Serving sizes
89
How were energy levels revised for Canada's Food guide?
The amount of food recommended by the food guide was determined (number of servings)
90
How were food groups revised for Canada's Food guide?
- Classify new foods
- Modernize the food and food groups in the guide
- Provide additional guidance related to foods
91
How were serving sizes revised for Canada's Food guide?
Addressed challenges with use and understanding (e.g. age-appropriate servings, terms, measures)
92
What three factors do nutrition recommendations focus on?
- Adjust energy intake to avoid becoming over- and underweight
- Varied diet to obtain adequate essential nutrients, as recommended by the RDA
- Lower fat (no more than 30% of energy intake) and saturated fat (no more than 10% of energy intake)
93
Does fat possess an RDA?
- No, fat is not an essential nutrient (no RDA)
| - Essential fatty acids are required nutrients (possess an AI)
94
What would occur if the population fat intake was below 30%?
A certain number of individuals will eat too little fat, and be at risk for essential fatty acid deficiency
95
What does a low-fat diet imply? What does that result in?
- Major shifts in the types of foods consumed (too little animal protein)
- Results in a decreased consumption and bioavailability of iron, zinc, and calcium
- RDAs are developed with bioavailability associated with a mixed protein diet
96
What is the fat recommendation for children?
Children slowly transition from a high-fat diet to no more than 30% of energy intake from age 2 to the end of adulthood
97
Which population group possesses a particularly important recommendation for fat?
- Children
| - They should not be consuming fat at less than 30% of their energy intake
98
What are the recommendations for carbohydrates?
- Majority of energy should be derived from carbohydrates from a variety of sources
- Increased intake of phytochemicals (protection against chronic diseases)
99
What are the recommendations for alcohol?
No more than 5% of energy intake from alcohol (1-2 drinks daily)
100
What are the risks of increased alcohol intake?
- Cancer
- Heart disease
- Osteoporosis, dementia, liver diseases, hypertension, obesity, fetal alcohol syndrome, accidents, domestic violence
101
What are the recommendations for caffeine?
No more caffeine than in 4 cups of coffee
102
What are the risks of increased caffeine intake?
- Osteoporosis
- Hypertension
- Adverse pregnancy outcomes
- Cardiovascular disease
103
What does a lower sodium content prevent?
- Essential hypertension
| - Cerebral hemorrhage
104
What quantity of fluoride should community water supplies contain? Why?
- Less than 1 mg/L
| - To prevent dental caries
105
What are the three major guiding principles of new dietary guidelines (e.g. Dietary Guidelines for Americans)?
1) Consume a variety of foods and beverages (emphasis on plant-based)
2) Limit the intake of processed and prepared foods
3) Provide the population with the proper knowledge and skill to navigate the complex food environment, learning to buy and prepare healthy foods
106
Consume less than __% of calories per day from added sugars.
10
107
Consume less than __% of calories per day from saturated fats.
10
108
Consume less than ____ mg/day of sodium.
2300
