Dietary assessment Flashcards
What are the four main methods of dietary assessment?
- 24 hour recalls
- Diet record
- FFQ
- Diet history
Why use dietary assessment?
- Examine nutrient intake
- Look at specific foods/ food groups
- Examine dietary patterns
___ in ____ toddlers are iron deficient
1 in 3
How much can fortified milk increase toddler’s iron status by?
~122% (though subconsciously reduced red meat)
How do you carry out a dietary assessment recall?
- Develop a quick list
- Probe for forgotten foods
- Obtain food details (cooking method, time, brand)
- Obtain portion size (familiar measures)
- Final review (last chance to collect info on food not remembered)
What is the goal of a 24 hour diet recall?
Capture actual intake over a pre-specified time
What different types of diet recalls are there?
+ paper or online
+ can use interviewer or self-administered
What are the limitations of a diet record?
- have to carry measuring equipment & diet record
- have to ask about contents of food
- may change way someone eats
What is a food frequency questionnaire used for?
To measure usual or habitual intake (assess the frequency of intake of certain foods & look at specific dietary sources of nutrients)
What is one important consideration to take into account when when carrying out FFQ’s?
Must be validated for population it is going to be used in.
What is a diet history?
A fact to face interview (similar to a diet recall) that asks about variations over a week to help gain understanding of someone’s usual intake.
What is a diet history usually evaluated against
Recommended servings (i.e. of alcohol & salt)
What are key things to consider when conducting a dietary assessment?
- All responses are confidential
- Be non-judgemental
- Do not ask leading questions (portion sizes, breakfast etc..)
- Accuracy of information is very important
What are sources of error in a dietary assessment?
+ Change what you report (interviewer judgemental)
+ forgot what you ate
+ hard to estimate portions
+ raw/cooked weight?
+ ignoring drinks
+ people not volunteering cause not interested (bias)
+ unsocially acceptable cause misrepresentations
What are food composition databases?
+ average nutrient content of wide ray of foods
+ NZ Foodfiles
What is validity?
The extent to which a method gives you the “correct” answer
What is the difference between relative & absolute validity?
Absolute requires precise measurement of intake, whilst relative validity is indirect.
What is Reliability/ Repeatability?
The extent which a method gives you a reproducible answer
What is accuracy?
Accuracy is the e extent to which the measurement is close to the true value
What is measurement error?
Difference between measured & true value
What is observed intake?
True intake + measurement error
What are the 2 types of measurement error?
Random & systematic error
What does measurement error lead too?
Attenuation of relationships & Bias
What is random error?
Error due to chance/ normal variation which leads to increased variability around the mean & decreased variability
(Doesn’t change Mean)