1. Food Records: principle and uses
Food Records: principle and uses
Two types:
- Estimated Food Records
- Weighed Food Records (Weighed Diet Record, WDR)
Principle and Uses:
- Based on recording portion sizes of actual foods consumed by an individual, estimated using household measures or weighed using dietary scales.
- Weighed Food Records ideal for scientific and controlled studies in particular when diet counseling or correlations of intake with biological parameters are involved.
- Uses: research, multi-center epidemiological studies, for controlled metabolic studies.
- Weighed food record respondents must be motivated, numerate and illiterate.
2. 24-hour recalls: principles and uses
24-hour recalls: principles and uses
Two types: Single & Repeated
Principle and Uses:
- assesses actual food intake of an individual during previous 24 hours period or preceding day.
- the number of 24-h recalls requires to estimate the usual nutrient intake of individuals depends on day-to-day variation in food intake within one individual (i.e., within-subject variation. If more than one-day recall is required, nonconsecutive days should be selected.
- 24hr recall data can be repeated during different seasons of the year to estimate the average food intake of individuals over a longer time period (i.e., usual food intake).
3. FFQ: principle and uses
FFQ: principle and uses
Two types: Qualitative and Semi-Quantitative
Principle and Uses:
- Assesses energy and/or nutrient intake by determining how frequently a person consumes a limited number of foods that are major sources of nutrients or of a particular dietary components in question during a specified time period (typically 6 months to 1 year)
- Provide data on habitual intakes of selected nutrients, certain foods or food groups
- Specific combination of food can be used as predictors for intakes of certain nutrients or non-nutrients, provided that the dietary intake components are concentrated in a relatively small number of foods or specific food groups, e.g. consumption of vitamin C are predicted from fresh fruits and fruit juice.
- Often designed to gain information about specific aspects of diet, such as dietary fats or particular vitamins or minerals, and other aspects may be less well characterized
- List of approximately =100 individual foods items or food groups that are important contributors to the specific nutrients of interest
- Should feature simple, well-defined food and food categories, avoid use of open-ended questions
- (Usually) self-administered; designed to be easy to complete by the study subjects
- Often rely on assumptions regarding portion size; limited by the amount of detail that it is feasible to include in the questionnaire
- It is possible for the questionnaires to be semi-quantitative where subjects are asked to estimate usual portion sizes
- In epidemiology, FFQ are often filled in with reference to the previous year in order to ascertain usual food consumption patterns for that period.
- The FFQ must be culture specific (Khonson, 2002)
