Mod 1 Flashcards
Interventional/experimental studies purpose
Purpose = test hypothesis
Interventional/experimental studies
Manipulate ≥ 1 factor and measure outcomes
Independent and dependent variables
Can determine causal relationships
Interventional/experimental studies limitation
Hard for nutrition because you can’t control all the variables
Epidemiological/observational studies purpose
Purpose = generate hypothesis
Epidemiological/observational studies
Test correlation between exposure and outcome
Can make associations and look at complex relationships
Epidemiological/observational studies limitation
Can’t prove a causal relationship
Cross-sectional
Measure exposures and outcomes simultaneously
Remember: NHANES study
Retrospective
Observe the outcome first and look back to determine the exposure
Compare an individual with a condition to an individual without
Prospective
Look at the exposure first and determine the outcome
Follow a group of people with similar characteristics over a long period of time
Necessary
If the cause is not there → the outcome won’t occur
Prerequisite
Test for Necessary
Prove by removing the factor
Sufficient
If the cause is there → the outcome will occur
Test for Sufficient
Prove by adding the factor in
Contributory
The cause is necessary and/or sufficient only under certain conditions
Issues with assessment of exposures
Lack of reliable measurements
Potential confounding factors and biases
24 Hr Recall
Food and drink recorded over 24 hours
Many not represent usual intake
Recall bias
Issues with assessment of health outcomes
Indexes and biomarkers of disease are used instead of the specific disease
Nutritional assessments are usually not specific to nutrition
Food frequency questionnaire
Food intake patterns
Limited in accuracy and completeness
Have to know target population
Food diary
Record when you consume food
Portion size estimated
Most accurate method
Observer effect
ABCs
Anthropometric measurements
Biochemical testing
Clinical assessment
Dietary assessment
Anthropometric measurements
Measurements and proportions of body
Biochemical testing
Lab tests
Clinical assessment
Physical exam
Dietary assessment
Diet + health history
Nutrition
Process by which a living organism obtains, assimilates, and uses nutrients or other food components for growth, maintenance of tissues, and reproduction
Nutrients
Chemical compounds in diet that organisms need to sustain life
Nutrients organism level
Promote growth
Maintain tissues
Regulate physiological processes
Nutrients cellular level
Provide energy
Structure for materials
Regulatory agents for processes
Macronutrients
Proteins
Lipids
Carbs
Water
Alcohol?
Micronutrients
Vitamins
Minerals
Water
Macro
Inorganic
Non NRG yielding
Carbs
Macro
Organic
NRG yielding
C, H, O
Lipids
Macro
Organic
NRG yielding
Membranes, signaling
Condense source of NRG
Protein
Macro
Organic
NRG yielding
C, H, O, N
Vitamins
Micro
Organic
Non NRG yielding (complex)
Regulatory agents, signaling, hormones
Minerals
Micro
Inorganic
Non NRG yielding
Nutrient Density
Number and amount of micronutrients in a food relative to its nrg content
mg/kcal
Energy density
Energy content of a food relative to its weight
kcal/g
Nutrient-dense food
high in essential nutrients but relatively low in calories
RDA
One value to meet the needs of a healthy population
Revised every 5 years
The levels of intake of essential nutrients that, based on scientific knowledge, are judged by the Food and Nutrition Board to be adequate to meet the known nutrient needs of practically all healthy persons
Goals for DRIs
Set recommended intake values for individuals (RDA + AI)
Facilitate nutrition research and policy for population (EAR)
Establish safety guidelines (UL)
Prevent chronic disease
AI
Adequate intake level
Established if data is insufficient for EAR/RDA
Nutrient intake goal for individuals
Based on avg intake of healthy populations that supports adequate nutritional status
UL
Tolerable upper intake level
Max daily intake that appears safe
Beyond the intake level, increased risk for adverse health effects
Calculate RDA
EAR + 2x SD
Intake goal
Btwn RDA and UL
DRI
the average daily intake level of a particular nutrient that is likely to meet the nutrient requirements of 97-98% of healthy individuals in a particular life stage or gender group
EAR
Average daily level of intake estimated to meet the requirements of 50% of healthy individuals
