421 - Week 2
what did the RDAs fail to address?
- chronic diseases - supplements
components of protocol**
- title - summary - project description: rationale, objectives, subjects, methods, statistical considerations (data analysis, sample size needed) - ethical considerations - references
HEI is derived on the adequacy of intake for -->
- total fruit - whole fruit - total vegetables - dark green and orange vegetables and legumes - total grains - whole grains - milk - meat and beans - oils (good ones)
DGA = practical advice (using words) to be understood by the public -->
----
DRIs are basis for all other information such as?
DGA, MyPlate, nutrition facts
can you use the RDA for assessing/planning groups?
NO
can you collect data on an individual level just because?
NO - need consent; can summarize data as a whole but can't individualize
DGA translate NUTRITIONAL SCIENCE into practical advice and are intended to address what??
NUTRITION RELATED PROBLEMS/chronic disease prevention (not just to ensure adequate intake)
reference amount
amounts of food that people customarily consume per eating occasion (expressed in metric units)
informed consent***
document providing the potential participant with INFORMATION needed to make an INFORMED DECISION about whether or not to participate in something
prospective study
follow subjects FORWARD IN TIME
MyPlate icon
fruits, veggies, grains, proteins, dairy
changes to the study & IRB
must inform before you do any changes
why are standards for food and nutrient intake important?
needed to ASSESS the ADEQUACY of an individual's or group's DIET
EAR
will meet requirements of 50% of the healthy individuals
UL
will pose NO RISK OF ADVERSE HEALTH EFFECTS FROM EXCESS at this level; MAX amount that can be TOLERATED
DGA vs DRIs
- DGA = QUALITATIVE advice to the PUBLIC about diet and CHRONIC disease prevention and maintaining health - DRIs = QUANTITATIVE advice to PROFESSIONALS about amounts of nutrients or food components to be found of benefit
standards for the evaluation of BOTH food and nutrient intake**
- Diet Quality Index (DQI) - Healthy Eating Index - US Dietary Guidelines
non-controlled trial
- all the participants are given a treatment and simply followed for a period - no control group in the study
randomized control trial (interventional)
- allocated at random (by chance) to receive one of several clinical interventions - one of these interventions is the standard of comparison or control
5 major themes of DGA
- balancing calories to maintain weight - foods and food components to reduce - foods and nutrients to increase - building healthy eating patterns - helping Americans make healthy choices
quantitative study
- classify or count variables of interest and use statistical models to evaluate data (data = #s and statistics) - done ahead of time
qualitative study
- complete, detailed description of subject matter of interest - data in WORDS, PICTURES, or OBJECTS
cohort (observational)
- enroll a group and follow over time - outcomes compared to examine people who were exposed or not exposed to a factor of interest
case-control (observational)
- enroll subjects WITH the disease of condition under study (cases) - enroll subjects of similar race, SES, age, WITHOUT the disease or condition under study (controls) - collect data prior to onset of disease
AMDR fat/CHO/protein
- fat = 20-35% - CHO = 45-65% - protein = 10-35%
observational
- individuals are OBSERVED or certain outcomes are measured - NO ATTEMPT IS MADE TO AFFECT THE OUTCOME!
HEI can also be used to... -->
- monitor changes in food consumption patterns - evaluate menus and diet plans - target areas in need of nutrition education programs
HEI is derived on the moderation of intake for -->
- saturated fat - sodium - calories from solid fats, alcoholic beverages, added sugars
selected messages of MyPlate --> (review)
1) balancing calories [enjoy but eat less; avoid oversized portions] 2) foods to increase [F&V, whole grains, skim milk] 3) foods to reduce [sodium, water]
4 types of observational studies
1) case series 2) case-control 3) cohort 4) cross sectional
2 types of interventional studies
1) randomized control trial (RCT) 2) non-controlled trial
how do you use the DRI?
1. assessing nutrient intakes 2. planning for nutrient intakes ---use then for individuals and groups
steps in research***
1. subject matter 2. search literature 3. develop hypothesis 4. design study 5. write study protocol and informed consent 6. review of protocol and informed consent by IRB 7. collect data 8. analyze data 9. disseminate results to the scientific community, this includes peer review
DQI - based on...? (name 4)
1. total fat 2. saturated fat 3. dietary cholesterol 4. servings of fruit/d 5. servings of vegetables/d 6. servings of grains/d 7. calcium intake 8. iron intake 9. dietary diversity 10. dietary moderation
in the absence of observations of known adverse effects, UL is?
10 times the RDA
The recommended intakes for most nutrients for infants up to age 1 year are expressed in terms of
AI
estimated energy requirement
AVERAGE DIETARY INTAKE to MAINTAIN ENERGY BALANCE in a person w/ good health
double blind randomized trial
BOTH the investigator and the subject are unaware of the exact treatment the subject is receiving
DRIs
COMPREHENSIVE set of standards
____ is an approach to help people plan diets that maintain adequate nutrient intake while minimizing consumption of unnecessary energy and reducing the intake of sodium, solid fats, dietary cholesterol, added sugars, and refined grain
Dietary Guidelines for Americans
standards for the evaluation of NUTRIENT intake***
Dietary Reference Intakes (DRIs)
Which one of the following represents the point of nutrient intake at which one half of the members of a given group will have its nutrient needs met while the remaining half will not?
EAR
RDA = ____+ 2 SD
EAR + 2 SD --> RDA is 20% higher than EAR b/c needs to meet needs of 98% of the population
DRIs consist of?
EAR, RDA, AI, UL
single blind randomized trial
EITHER the investigator or the subject, but NOT BOTH of them, is unaware of the exact treatment the subject is receiving
DRIs developed by?
Food and Nutrition Board of the National Academy of Sciences and the Canadian National Institute of Nutrition and Health Canada
Which one of the following was developed by the USDA for assessing the quality of the diets of Americans?
HEI
what is the only index issued by U.S. federal government and used on a regular basis to gauge overall diet quality of Americans?
HEI
IRB stands for?
Institutional Review Board or independent ethics committee (IEC)
AI
LACK OF DATA (used when EAR/RDA are not known)
retrospective study
LOOKS AT AN OUTCOME, then attempts to uncover CAUSES or relationships by GOING BACK IN TIME
standards for the evaluation of FOOD intake***
MyPlate
what does RDA stand for?
Recommended Dietary Allowances
study design examples -->
SEE PPT to test knowledge!
why are longitudinal studies useful?
TREND ANALYSIS, tracking changes over time, evaluating an intervention
T/F: Since they were first established in 1980, a basic premise of the Dietary Guidelines for Americans has been that nutrient needs should be met primarily by consuming naturally occurring foods as opposed to relying on fortified foods or dietary supplements.
TRUE
T/F: The "reference amount" is the amount of a food that people customarily consume per eating occasion and which is used by the U.S. Food and Drug Association in establishing the serving size in the Nutrition Facts label for that food.
TRUE
T/F: The primary purpose of the Dietary Guidelines for Americans is to prevent or delay the onset of chronic diseases.
TRUE
what is a protocol?**
WRITTEN REPORT of ENTIRE study
what is a hypothesis?
a probable or expected outcome of your study
2 principles HEI is based on?***
adequacy and moderation
IRB does what?
approve, monitor, and REVIEW biomedical and behavioral research involving humans, with the aim to PROTECT the RIGHTS and welfare of the research subjects
observational standard**
based on OBSERVED or experimentally derived approximations of average nutrient intake that appear to maintain a defined nutritional state or criterion of adequacy in a group of people
The recommendations contained within the Dietary Guidelines for Americans are applicable to the general public living in the U.S.
beginning at about 2 y/o
why are prospective studies good?
bias and confounding factors are minimized
cross sectional (observational)
conduct a survey of a sample of population elements at one point in time
Healthy Eating Index (HEI) assesses diet quality based on?
current Dietary Guidelines for Americans
case series (observational)
descriptive observation, small patient group / generally NO controls
AMDR
guidance on the amount of a particular MACRONUTRIENT needed to assure ADEQUATE INTAKE intake and to reduce risk of chronic disease while providing intakes of essential nutrients
why are retrospective studies good?
help to study uncommon outcomes since a large number of subjects can be studied
dietary quality index (DQI)
instrument used to assess the OVERALL DIET QUALIITY of groups and evaluate risk for chronic disease related to dietary pattern; numeric score used
longitudinal study
involves taking REPEATED MEASURES OVER TIME
what is a requirement?
lowest continuing intake level that will maintain a defined level of nutriture
MyPlate is designed for..?
maintainin/improving health NOT particular diseases
RDA
meet requirements of NEARLY ALL 97-98% of individuals
A food's vitamin and mineral content relative to its energy content is known as ____
nutrient density
food guide
nutrition education tools that translate dietary standards and recommendations into understandable and practical forms for use by those who have little or no training in nutrition (one example = MyPlate)
DGA are intended for?**
people 2 y/o and older!
what are the RDAs?
precursor to the DRIs
most important objective is?
primary - most important Q to answer
why are cross-sectional studies good?
quick snapshot of what's going on!
Daily Reference Values
reference values for nutrients and food components for which no set of standards previously existed (ex: total fat is <65g, saturated fat is <20g, total CHO is 300g (these are the numbers used on the bottom of the food label)]
Reference Daily Intakes
reference values for vitamins and minerals - micronutrients (are the RDAs but w/ a new name) - RDIs and DRVs referred to as Daily Values (DVs)
cross-sectional study
samples population elements AT ONE POINT IN TIME
UL is important in relation to?
supplements
interventional studies are useful for..?
testing a CAUSE/EFFECT relationship
primary focus for RDAs
to prevent DEFICIENCY diseases - set at a high level to meet needs of all healthy persons
interventional study
treatment is implemented and effect of the treatment is evaluated
why do a literature review?**
understand CURRENT KNOWLEDGE and PREVENT REDUNDANCY
