Dietary Reference Intakes. Food pyramid(s) are devised based on the food choices that are necessary...
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Transcript of Dietary Reference Intakes. Food pyramid(s) are devised based on the food choices that are necessary...
Dietary Reference Intakes
Food pyramid(s) are devised based on the food choices that are necessary in order to meet the Dietary Reference Intakes.
Different pyramids can be constructed based on the biases of the “author”.
By following the food-serving recommendations of the USDA food pyramid , one would meet all of the nutrient requirements recommended by the DRI.
Because the USDA is a political body, some of the food servings have been derived based in part on lobbying efforts by certain elements within the food industry; meat, for example.
Healthy LifestyleFood Pyramid
©C. Murray Ardies
The Healthy Lifestyle Food Pyramid* also meets the DRI but is vegetarian-based & provides a phytochemical-rich diet that promotes prevention of a variety of chronic diseases and it includes specific requirements for exercise to enhance prevention .
The meat component is optional because the nuts-seeds-beans-legumes component comprises a meat-substitute and the only meat recommendation is 2 servings of fish/week.
*Optimal Health Guide – Stipes Publishing, LLC, Champaign Illinois, http://www.stipes.com/health.html
Food And Nutrition Board IOM-NAS (USA)1993 Symposium - Should RDA’s be Revised?
Canadian National Institute of Nutrition (Health Canada)1990 Symposium - Should RNI’s be Revised?
Food & Nutrition BoardCanadian National Institute of Nutrition
1995
Created the Standing Committee on the Scientific Evaluation of Dietary Reference Intakes
To revise existing nutritional standards based on new information to create
Nutrient-Based Recommendations to Serve North America
A Brief History
IOM Publications (DRI)
1997 - Calcium, Phosphorus, Magnesium, Vitamin D & Fluoride
2000 - Thiamin, Riboflavin, Niacin, B6, Folate, B12, Pantothenic Acid, Biotin, & Choline - C, E, Selenium Carotenoids
2001 - A, K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium & Zinc
2002 - Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein & Amino Acids
2004 - Water, Potassium, Sodium, Chloride & Sulfate
Dietary Reference Intakes Replace the RNI and RDA for Healthy Individuals
Estimated Average Requirement: EAR
Recommended Dietary Allowance: RDA
Adequate Intake: AI
Tolerable Upper Limit: UL
Based on:
Research Experiments/Surveys: ConsumptionDisease IncidenceDisease PreventionBiochemical Function
Biochemical correlates associated with nutrientfunction are used to determine adequacy.
The recommendations are based on the distribution of the specific analyses within the target population
(including specific function and its relation todisease and disease prevention).
Thus the DRI’s are really statistical estimates of population parameters related to
nutrient intake & health.
DRI’s
EAR Use to examine the possibility of inadequate reported intakeRDA Usual intakes at this level have a low possibility of inadequacyAI Usual intakes at this level have a low probability of inadequacyUL Usual intakes above this level have a risk for adverse effects
RDA & Health
Inclusion of health indices has altered some RDA’s dramatically (a few examples):
Vitamin C + 25% ♀ & ♂
Folic Acid + 100% ♀ & ♂
Vitamin E + 100% ♀ & + 50% ♂
Iron + 20% ♀ & - 20% ♂
Copper - 50% ♀ & ♂
A Wee Bit of Diet Analysis Stuff …
Evaluation of true nutritional status requires clinical, biochemical, and anthropomorphic data
Diet analysis requires an accurate measure of usual intake and addresses the question:
Is an individuals dietary intake adequate to meet their Nutritional Requirements?
To be adequate an individuals usual intake (y) should be equal to or exceed the individuals requirement for that nutrient (p):
If y > p then y is adequate
If y < p then y is inadequate
An individuals actual nutritional requirement (p) is unknownAn Individuals usual intake (y) is unknown
Because the DRI’s are statistical constructs a statistical approach is necessary
EAR is used as an estimate of r and SD of r is proportional to the uncertainty about how accurately r estimates p.
Mean intake over n days (y) is used as an estimate of y and SD of y is proportional to the uncertainty about how accurately y estimates y.
For practical purposes y and r are used instead of y and p and the difference (D) between y and r is used to make inferences regarding adequacy of the diet
D = y - r
Because of uncertainty of both y and r, SDD must be calculated and the ratio of D / SDD is used to construct a level of confidence
SDD = Vr + (Vwithin / n)√
Use z-score values to determine levels of confidence for the D/SDD ratio