Download - Dietary Assessment Individu Intro 2012
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DIETARY ASSESSMENT: INDIVIDUAL LEVEL
NIA N WIRAWAN NUTRITIONAL ASSESSMENT COURSE
Nutrition Study Program Faculty of Medicine Brawijaya University
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The Importance for Conducting Dietary Intakes
Dietary Assessment: assess the first sign of any nutritional deficiency
Can be used to predict possible nutrient deficiency
Assessing and monitoring food and nutrient intake
Formulating and evaluating government health and agricultural policy
Conducting epidemiologic research
Uses for commercial purposes
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National and Household level
Level
Individual level
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Individual Dietary Assessment Method
Quantitative Daily consumption weight or volume of food eaten on one day or over a period of days average daily intake: Recall Records
Types of Data
Qualitative food habitually eaten Retrospective on food pattern: Dietary historty FFQ
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Quantitative methods Qualitative methods:
measure or estimate the weight or volume of food eaten by an individual or group on one day or over a period of days
Could estimates quantitative usual intake if the number of measuring days is increased
do not assess portion sizes so that data on nutrient intakes not available
record the kinds of food habitually eaten by an individual over a period of time in the past
results provide information on the usual food consumption patterns of an individual or group
Quantitative and qualitative methods
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FOOD CONSUMPTION AT INDIVIDUAL LEVEL
24-hr recall (single and repeated)
Food records (estimated and weighed)
Food Frequency Questionnaire
Dietary history
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Characteristic of respondents
Study Objective
Motivation
Dieting
Validity and reproducibility of method
Respondent Burden
Available Resources
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Level 1: Mean intake of a group single 24-h recall/food record all days of the week are proportionately represented in final sample
Level 2: Population percentage at risk to inadequate intakes Repeat 24-h recalls/records at least 2 days on sub sample (30-40) Non-consecutive days (if 2 repeats) If non consecutive, 3 repeat are needed
Level 3 : Rank intakes of subjects within distribution multiple observations of 24-h recalls/records; alternative semi-FFQ
Larger number of replicates required Alternatively semi FFQ or FFQ or dietary history
Level 4: Usual intakes for correlation or counseling
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Level Study Objective
1 Describe: usual mean nutrient intake for a group Significant difference in mean/median intake of a group Change in group mean intake (before after intervention/paired or unpaired)
2 Distribution of intake within group proportion at risk of inadequacy Change in proportion at risk of inadequacy before and after intervention Change in proportion at risk between group Risk of inadequacy in specific sub group defined by SES, sex, etc
3 Relationship between frequency of food group (deciles of green leafy vegetables) vs mean level of biomarker Divide subject into tertiles of nutrient and calculate the corresponding average biomarker level for each tertile
4 Relationship between nutrient intake of individuals to other indices of nutritional status measured in the same person
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LEVEL 2 Proportion (%) of
population at risk of inadequate intake
LEVEL 1 Mean intake of
a group
LEVEL 3 Usual intake of
individuals for ranking within a group for linking with risk of
chronic disease
LEVEL 4 Usual intake of
nutrients in individuals for counseling/ correlation or
regression analysis
SINGLE 24 H RECALL/food
record
REPEATED 24 H RECALL/food records
SEMI Quantitative FFQ
All days of the week equally represented in final sample
Number of sample Gibson 05. p. 55)
At least 2 replicates in sub sample (30-
40 individuals represent age
range) if nonconsecutive, or
3 replicates for consecutive
DIETARY HISTORY
Replicates in all
Number of days in
Gibson 05 p. 57
Replicates in all
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Particularly applied for
quantitative methods 1. Measuring food intakes
2. Conversion of foods to nutrients
3. Estimate of absorbed intakes of nutrients
4. Adequacy of nutrient intakes relative to requirements
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24-HOUR RECALLS
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Principle and use
To assess actual food intake of an individual during previous 24-h period
Non consecutive day
Can be repeated during seasons of the year to estimate average food intake of individuals over a longer time period
Can be conducted for children >=8 years and most adults except person with poor memories
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Single 24-h recall
Not sufficient to describe an individuals intake of food and nutrients
Single 24-hr recalls used for large scale field studies to characterize average intakes of population groups (subjects are representative, all days of the week are represented)
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Repeated 24-h recalls
Can be used to assess usual nutrient intakes for an individual
Repeated 24-hr recalls on a sub-group of the population can be used to assess prevalence of inadequate nutrient intakes within each sub-group
Nutrient intake data can form the basis of subsequent nutrition education programs
If it is not possible to carried repeated measures of all respondents sub-sample
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Methods
Respondents: recall all foods and beverages eaten in the
past 24-h
Describe in detail each food item consumed
Estimates portion sizes in common HH measures
Interviewer: check the recall with respondent
Converts portion sizes into gram equivalent
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MULTIPLE PASS 24-HR RECALL
A complete list of all foods and beverages consumed during the preceding day is obtained
Detailed description of each food and beverages consumed (cooking method, brand names)
Amounts of each food and beverages item consumed in HH measurements
The recall is reviewed to ensure all items, including use of vitamin and minerals supplements
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Strengths of 24-hr recalls
Simple, easy and quick to administer
Provides a qualitative description of the dietary pattern as well as nutrient intakes
Can be used for both illiterate and literate
Relatively inexpensive
Non-threatening
Element of surprise so less chance of altering diet
Wide sampling coverage possible
Respondent burden low so response rate is usually high
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Weaknesses of 24-hr recalls
Relies on memory and hence may not be reliable
Prone to errors in estimating portion sizes consumed
May not reflect the usual intake of the group if recalls do not represent all days of the week
May be difficult to find appropriate time for recall interview
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Weaknesses of 24-hr recalls
Continuous questioning and answering is tiring for both the respondent and the interviewer and may result in errors
Prone to errors when portion size estimates are converted to gram equivalents
Prone to errors in coding food items if limited number of food items in database
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24-h-Recalls and Food Records
Number, selection and spacing of days depends on:
Food intake
Nutrient of interest
Day to day variation
Level of precision required
Weighed food record is the most precise method
Preferred method to make correlation between usual intake with biological parameters
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FOOD RECORDS
Estimated food records
Weighed food records
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PRINCIPLE AND USE
Based on recording portion sizes of actual foods consumed by an individual (Estimated HH measures or Weighed using dietary scales)
Uses for research
Multi-center epidemiological studies
For controlled metabolic studies
If a weighed food record method is used, respondents must be motivated, numerate and literate
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METHODS
Record a complete description of all foods and drinks as they are consumed in
Detail description: name (local and general if known) method of cooking state of food (e.g., raw, cooked, peeled,
refined) brand names where applicable all condiments, herbs, and spices method of food preparation and cooking
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METHODS
Weigh the amounts consumed (portion served minus left over) or estimate using household measures and calibrated household utensils
Foods eaten away from home records descriptions of the amount of food eaten. Nutritionist buy and weigh duplicate portion of each recorded food eaten, if possible assess the probable weight consumed
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RECORDING OF MIXED DISHES
describe method of preparation and cooking
weigh edible portion of each raw ingredient or estimate using household measures
record final weight (or volume) of cooked food
record weight of portion size consumed or estimate using household measures and/or calibrated household utensils
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STRENGTHS OF FOOD RECORDS
Do not rely on memory Provide accurate data on portion size consumed,
especially when weighed Can be used with illiterate participants provided
interviewer does the measurements Said to be reasonably valid for up to 5 days Can assess food patterns as well as the socio-
demographic environment of respondent Can enhance interpretation of laboratory,
anthropometric and clinical data Multiple day data more representative of usual
intake
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WEAKNESSES of food records
Require high degree of cooperation Act of recording may alter habitual diet High respondent burden may result in low
response rate Subjects must be literate to complete the
records Time-consuming Labor-intensive and expensive Significant under-reporting may still occur
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References
Cameron ME and WAV Staveren (1988). Manual on Methodology for Food Consumption Studies. Oxford University Press, New York
Gibson RS. (2005). Principles of Nutritional Assessment. Oxford University Press, New York
Jelliffe DB, Jelliffe EFP. (1989). Community Nutritional Assessment. Oxford University Press, New York.
Lee RD, Nieman DC. (1996). Nutritional Assessment (2nd edition). The McGraw-Hill Companies, America.