DIETARY ASSESSMENT: INDIVIDUAL LEVEL

NIA N WIRAWAN NUTRITIONAL ASSESSMENT COURSE

Nutrition Study Program Faculty of Medicine Brawijaya University

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

National and Household level

Level

Individual level

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

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

FOOD CONSUMPTION AT INDIVIDUAL LEVEL

24-hr recall (single and repeated)

Food records (estimated and weighed)

Food Frequency Questionnaire

Dietary history

Characteristic of respondents

Study Objective

Motivation

Dieting

Validity and reproducibility of method

Respondent Burden

Available Resources

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

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

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

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

24-HOUR RECALLS

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

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)

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

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

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

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

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

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

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

FOOD RECORDS

Estimated food records

Weighed food records

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

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

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

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

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

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

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.