1. DIETARY ASSESSMENT AND
LINKS
WITH NUTRITIONAL
ASSESSMENT
#6C
Lalita Bhattacharjee
Nutritionist
National Food Policy Capacity Strengthening Programme
Food and Agriculture Organization of the United Nations
Bangladesh
Presented on 5 July 2011
at the
Training Workshop on “Food Security Concepts, Basic Facts and
Measurement Issues”
2. OUTLINE
Introduction
National and household food consumption surveys
Individual dietary assessment
Rapid methods of dietary assessment, micronutrient
assessment and FFQ
Validation of dietary assessment
Dietary diversity
Conversion of dietary intakes to nutrients
Conclusion
3. Dimensions and methods for
assessing food security and under
nutrition
Methods Availability Access to Consumption Utilization
of food food of food of
nutrients
FAO Method
Household
income
& expenditure
surveys
Individual food
consumption/
intake surveys
Anthropometry
Qualitative
measures of
food security
4. DIETARY ASSESSMENT AND
NUTRITIONAL ASSESSMENT
A DIETARY ASSESMENT is a comprehensive evaluation of a person's
food intake. It is one of the established methods of nutritional
assessment. Dietary assessment techniques range from food records
to questionnaires and biological markers.
NUTRITIONAL ASSESSMENT is more comprehensive and includes d
determining nutritional status by analyzing the individual’s brief socio
economic background, medical
history, dietary, anthropometric, biochemical, clinical data and drug –
nutrient interactions
NUTRITIONAL STATUS is the measurement of the extent to which an
individual’s physiologic need for nutrients is being met
NUTRIENT INTAKE depends on actual food consumption which is
influenced by factors such as economic situation, eating
behaviour, emotional climate, cultural influences, effects of disease
states on appetite and the ability to absorb nutrients
NUTRIENT REQUIREMENTS are determined and influenced by
age, sex, BMR, physiological status, activity patterns, physiologic
6. DIETARY ASSESSMENT
PRINCIPLES
Adequacy : a diet that provides enough energy and nutrients to
meet the needs according to the recommended dietary allowances
for good health
Balance : a diet that provides enough, but not too much of each
type of food
Variety : a diet that includes a wide selection of foods within each
food group
Nutrient Density : a diet that includes foods that provide the most
nutrients for the least number of calories (nutrient dense foods)
Moderation : A diet that limits intake of foods high in sugar and fat
7. Methods of assessing dietary
intake
National food supply data
Household data
Individual data (Food records, 24 hr dietary
recall, FFQs, diet histories,food habit
questionnaires, combined methods
RAP - rapid assessment procedure ( focus
groups to gather information on food
behaviours, beliefs and intakes)
8. National and household food
consumption
Food consumption data collected at national, HH
or individual levels
Individual intake data required for assessing
nutrient adequacy
Food supply and HH data can provide useful
information
Food consumption assessment at national level
based on FBS ( per capita availability, no
individual variation in food intake)
Food supply data useful
9. National and household level
consumption
Preferred source of food consumption surveys (
provide more information than FBS)
Provide consumption characteristics of specific
vulnerable groups including those from urban
/rural populations
HIES 2010
14. (En%) of
cereals and rice to Bangladesh
diet
Source/Year Energy Cereal (g) Rice (g)
intake (kcal) En % En %
452 440
HIES 2005 2238
70% 68%
442 416
HIES 2010 2318
66% 64%
15. Potential key indicators to be mapped at national
&sub-national levels by sector : FOOD AND
NUTRITION
Food intake indicators
Average energy intake Percentage of energy from fat
Average food intake of major Percentage of protein from
food groups animal source
Daily per caput protein intake Percentage of protein from
vegetable source
Percentage of energy from
protein Dietary Energy Supply
Daily per caput carbohydrate Percentage of undernourished
intake population
Percentage of energy from
carbohydrates
Daily per caput fat intake
16. Assessment of individual intakes
Dietary records
Record all foods and beverages consumed over a specific
time period ( 3-4 d)
Amount consumed determined by weighing with a scale or
measuring volume using standard cups and spoons
Specific/special foods may be recorded (fat, vitamin A, iron
rich)
Total energy intake will require all foods to be recorded.
17. Assessment of individual
intakes
24 hour recall :
Recall all the foods and beverages consumed the
previous day or 24 hours prior to the interview
Interviewers should be knowledgeable about foods
available in the market
Regional and ethnic preparations and methods
Interview conducted face –to-face, structured w/o probing
questions
Estimates of portion size are made using standardized
cups and spoons
Record of food amounts converted into nutrient intakes
using food composition tables
18. Assessment of individual
intakes
Food frequency questionnaire (FFQ)
Report usual frequency of consumption of each
food item from a list of food items in reference
to a specified period (past wk/mo/yr)
Face to face interview, telephone or by self
administration
Describes dietary patterns or food habits not
nutrient intake
Semi quantified tools can obtain information on
portion size using household measures
19. Estimating average intake of
nutrients
Specification of portion size – standardized
portions (Willet )
Description of portion size – small, medium, large
(Block)
Information on frequency and serving size allows
for estimating nutrient intakes
Food list should contain foods that contribute to
majority of the nutrients/specific in the diet
% adequacy of food groups
% adequacy of RDA for energy and nutrients
Used in epidemiological research to study diet
20. Assessment of individual
intakes
Diet history
• Collection of information on frequency of intake of
various
• foods and usual meal pattern
• Entails detailed listing of foods and beverages
consumed at each eating session
• 3 d - diet record as an independent check on food
intake
• Methods of preparation
21. Rapid methods for community
dietary
assessment
Dietary assessment of development of culture -
HHs with children under 5s specific relevant food usage
list
Rapid assessment survey
(focus group interviews, Linking food intake data with
weighing /measuring of
selected target group
children & mother
interviews IYCF practices,
Derive mother’s BMI from
Social customs and food standard tables
beliefs, behaviours &
intakes
Key informants –
community leaders, local
shop owners or health
personnel
Small clusters of women
5-6 women sufficient for
FGD
22. Strengths and limitations of dietary assessment
methods
Method Strengths Limitations
Food record Does not rely on memory; open ended High participation burden; requires
literacy; may alter intake behaviour (
?? community use )
24 hr recall Immediate recall period, easy to obtain Relies on memory; requires skilled
information; since interviewers interviewer; does not reflect the
administer tool & records the usual dietary intake
responses, literacy is not a ( need for food list, std menu
problem, respondent burden minimal; types; need for community based
does not alter intake behaviour; wide training ) memory; requires complex
FFQs Inexpensive ; preferred for nutrients
range of use Relies on
with high day-to-day variability; does calculations to estimate frequencies;
not alter intake behaviour; lower requires literacy, doe not quantify
respondent burden; epidemiological intake ( need for exhaustive food
research to study diet-disease list; need for manual tally type
relationships calculations)
Food habit Rapid &low cost; does not alter intake may rely on memory; may require
questionnaire behaviour trained interviewer ( need for food
list; std menu types; community
based training)
Relies on memory; may require
Diet history No literacy needed; trained interviewer ( need for food
list & community based training
23. Selecting appropriate methods for
community dietary assessment
RAP –low cost, primary method for collecting
dietary data (locally available /commonly
consumed foods, dietary habits, behaviour)
Household surveys – provide data on foods
consumed by HH not individuals
Point to which foods are major contributors to
nutrients of particular concern ( identify
vulnerability/at risk of dietary deficiency - e.g no
fresh vegetables/fruits, lack of DGLV/YOV–lack of
vitamin C & A in diet; inadequate presence of
dietary enhancers for iron absorption??)
Food record and 24 hr recall methods of choice
for estimating mean intakes
Combine with quantitative dietary intake methods
to obtain individual nutrient intakes
24. Simplified assessment for specific
nutrients
FFQ
Simple, short questionnaires
Assessing intakes of specific nutrients to study diet –
disease relationships
Questionnaires should focus on assessing intakes of
specific nutrients (e.g calcium and osteoporosis, anti
oxidants and CD –cancer, heart disease, V&F and
certain cancers, specific micronutrients and
VAD, anemia; iodized salt, sea foods and fortified foods
and IDD)
Questionnaires need to be tested in diverse populations
to assess validity
VS, HKI Simplified FFQ
25. Validation of dietary
methods
Need to establish validity and reliability
Validity - how well it measures what it purports to
measure (accuracy)
Reliability – how well it agrees on retesting under
the same conditions (consistency)
Assessment of reliability is feasible , validity
poses a problem
Gold standard established – dietary record/direct
observation of subject’s consumption
Reference for validation
26. Relative validation
Unlike other methods, 24 hr recall is more susceptive to
direct validation
Since time covered is short and limited, direct observation
and measurements of intake are possible and also
practical
Studies that compared 24 hr recall with observation
and weighed duplicate meals have found that that the
2 methods yield similar results
Dietary intake varies from day to day, single recall may not
be representative
Many studies confirm that variations within
individuals, mean intake of group was not found to be
significantly different from day to day
Inter individual variability is less marked than intra
individual variation
27. Errors in dietary surveys
RANDOM (reduced reliability)
Generate larger total variances
Reduce the statistical power to detect association between
intake and a disease
Accentuate the estimates of possible associations
SYSTEMATIC (bias)
Represent greater hazards than random errors
Alter results
Very little can be done to correct for their effect
Structure of errors differs according to type of survey
method
Methods relying on simple recall or ability to provide reliable
estimates
of usual eating habits tend to be more prone to systematic errors
while
28. SOURCES OF ERROR IN DIETARY
ASSESSMENT
METHODS (INDIVIDUAL INTAKES)
Source of Weighed food Estimated 24 hr recall Dietary history
error records food weight and FFQs
records
FCT /recipe + + + +
books
Food coding + + + +
Wrong weight _ + + +
of foods
Reporting error _ _ + +
Variation of + + + _
diet with time
Wrong _ _ _ +
frequency
Modified ± ± _ _
eating pattern
Response bias ± ± ± ±
Sampling bias + + + Ferro –Luzzi in FAO, 2002
Source: Anna +
29. Illustration of association
between dietary adequacy and
anthropometry
Prevalence % % Total
of UW inadequate adequate
% <-2SDs 20 10 30
% > -2SDs 0 70 70
Total 20 80 100
Source : Mason, 2002 in “Measurement and Assessment of Food Deprivation and Undernutrition”, FAO
30. Dietary diversity (DD) : when to
measure
Objective Timing
Assessment of the In rural, agriculture In non agriculture based
typical diet of based communities communities
HH/individuals
When food supplies are Anytime of the year (if
still adequate (maybe seasonality is not an issue)
up to 4-5 mo after the
main harvest)
Looking at DD at
different points in the
agricultural cycle is one
way of investigating
seasonality of food
security
In many areas there are
important seasonal
differences in dietary
patterns.
For a more complete
assessment of usual
diet, DD should be
31. Dietary diversity (DD) : when to
measure
Objective Timing
Assessment of the food security During the period of greatest food
situation in rural, agriculture-based shortage, such as immediately prior
communities to the harvest or immediately after
emergencies or natural disasters
This may also serve as a baseline
for monitoring change for
investigating seasonality
Assessment of the food security At the moment of concern to identify
situation in non-agricultural a possible food security problem
communities May also serve as a baseline for
monitoring changes due to an
intervention
Monitoring of food security/nutrition Repeated measures to assess
programmes or agricultural impact of the intervention on the
interventions such as crop and quality of the diet, conducted at the
livelihood diversification same time of year as the baseline
(to avoid interference due to
32. Dietary diversity : Key steps
Activities prior to data collection
Translation and adaptation steps
Review
Key informant and community meetings
Refining the food lists and translations
Use of local names
Technical issues
Minimum quantities
Individual food items that can be classified into more than one
food group
Mixed dishes
Training
Instructions for administering the questionnaire
Household level
Analyzing dietary diversity data
Dietary diversity scores
33. DIETARY DIVERSITY SCORES : Aggregation of food groups to create HDDS and
WDDS
HDDS WDDS
Question no. Food Group Question no. Food Group
1. Cereals 1,2 Starchy staples
2. White tubers and 4 Dark green leafy
roots vegetables
3,4,5 Vegetables 3,6 and red palm oil Other vitamin A rich
as applicable fruits and vegetables
6,7 Fruits 5,7 Other fruits and
vegetables
8,9 Meat 8 Organ meat
10 Egg 9,11 Meat and fish
11 Fish and other sea 10 Egg
food
12 Legumes, nuts and 12 Legumes, nuts and
seeds seeds
13 Milk and milk products 13 Milk and milk products
14 Oils and fats
15 Sweets
16 Spices, condiments
and beverages
34. Food groups consumed by ≥ 50 % HH
by
diversity tertiles
Lowest dietary Medium dietary High dietary diversity
diversity (≤ 3 food diversity (≥ 6 food groups)
groups ) ( 4 and 5 food groups)
Cereals Cereals Cereals
Green leafy vegetables Green leafy vegetables Green leafy vegetables
Vitamin A rich fruit Oil Vitamin A rich fruit
Oil
Other vegetables
Fish
Legumes, nuts and
seeds
Source: FAO, 2010
35. Measures and use of DD
Dietary diversity as a measure of HH access and
food consumption can be triangulated with other
food related information
Gives a holistic picture of food and nutrition
security status across a broader area
DD being used increasingly to provide indicators
of HH access and individual dietary quality
Contextual use : Baseline and impact
assessment , national surveys, surveillance
systems, M&E of programmes and policies
Phase classification for identifying emergencies
37. Easy way to count your calories
(Measures providing 100 kcal
Cereals : 30 g ( 1/5 cup) Egg : 60 g ( 1 medium size)
Bread : 40 g ( 2 slices) Chicken : 90 g ( 3 small
Pulses : 30 (2 Tbsp) pieces)
Leafy vegetables (sak): 250 g Mutton: 85 g
( 2 small bunches) Fish (lean) 100 g
Other vegetables : 400 g (4 Fish (fatty) 60 g
cups) Shrimp : 30 g
Potato : 100 ( 1 cup) Prawn : 100 g
Nuts/oilseeds : 20 g (handful) Sugar : 25 g ( 5 tsp)
Fruit : 150 g/ 1-2 fruits Spices : 40 g ( 6 tsp)
Milk/Curd :150 ml ( 1 cup) Oil/ghee : 10 g (2 tsp)
Butter milk (ghol) : 670 ml ( 4 Butter : 15 g (1 Tbsp)
cups)
Channa/paneer/cheese : 30 g
(1 pkt)
41. Conclusions
Need to use core indicators linked to food security &
nutrition outcomes;
Identify food and nutrition vulnerability through information
on food consumption patterns
Need to obtain information on intra household distribution
of food for accurate assessment of individual intakes;
Differential nutritional status associated with differences in
morbidity or illness or other factors within HHs provides
valuable information on food distribution
Knowledge of HH food allocation patterns and underlying
reasons for food / diet related behaviour, so that
effectiveness of nutrition interventions can be improved.
42. Conclusions
Choice of method : Information needed, resources
available
Food/nutrients of primary interest, group/vs individual
data, absolute /vs relative intake , population
characteristics
Include statistical expertise while designing survey and
questions
Can provide qualitative data on dietary intake of HH
Can be combined with other methods to obtain individual
quantitative data
When absolute vs relative estimates are required, food
record, 24 dietary recall are methods of choice
For day –to-day variability – FFQ useful
DD – dietary patterns/habits/semi qualitative can be
quantified
Dietary assessment is essential to identify populations at
risk
Notas do Editor
Inter
The above table provides a graphical presentation of the per capita food intake in g with rural-urban break up from HIES 1991 -92 to HIES 2010. The trend in food consumption (intake) pattern over the past 30 years the total per capita food consumption (intake) in Bangladesh has increased steadily; an increase of 5.51% is noted in the last 5 yrs at the national level. Increase in food intake over the years could attributed to increases in food production, coupled with an improvement of socio-economic status of the people. While the intake in urban households has been higher than rural, the current per capita intake shows a higher level among rural than urban populations.
Consumption of food items is highly dependent on availability of food, price levels, food habits and ultimately purchasing behaviour. That the consumption of rice shows a relative decline in relation to an increase in total food intake is indicative of diversification of diets in Bangladesh, though at a slow pace. A decrease from 461 g/d in 2005 to 442 g cereals in 2010 is noted. A decrease of 2.1% is noted where Cer En % now contributes to 66% dietary energy compared to a previous contribution of 68%. Consumption of rice has decreased to 416g in 2010 from 440 g in 2005 which amounts to a decrease of 5.37% of rice En in the diet. Intake of animal foods rich in protein and micronutrients has increased to 109 g/capita/d in 2010 from 95 g in 2005. This amounts to an increase of nearly 15 % over the period. Similarly the intake of vegetables and fruits has increased to 211 g from 190 g per capita/d which amounts to an increase of 11% over the period. Pulses which are an important source of protein has remained almost the remain and continues to be much below the requirement. The production of pulses has been steadily declining due to the land being competed for production of other crops. The import of pulses has also not increased. Consumption of edible oil has increased by 25% (almost ¼) which could be a source of concern if an increasing trend in consumption is continued. On the whole, diversification of diets merits attention and needs to be accelerated given its role in sustaining diets and enhancing delivery on nutrition outcomes. by increasing intakes ofnon-cereal foods, particularly meat, egg, potato, fruits and vegetables (Figure 3).
The overall energy intake per capita/d significantly increased to 2318kal in 2010 from 2238 kcal in 2005 ( recording an increase of 3.56%) a finding markedly different from the previous surveys. While the increase is noted in both rural and urban areas, it has increased more in the rural areas ( 2344 kcal in 2010 from 2253 kcal in 2005) with an increase of 91 kcal/d (4.06%) during this period. In the urban areas, it ahs increased to 2244kcal in 2010 from 2194 kcal in 2005 reflecting an increase of 51 kcal/d (2.31 %) during this period. Significant increase of per capita/d energy intake might be attributed to changing food habits, increase in income and subsequent purchasing power and availability of convenience foods on the shelf (small shops and markets in both urban and rural areas). The higher level of energy intake in the rural areas compared to the urban area could also be attributed to the higher energy requirements of the rural population given their occupation in heavy work related to agricultural labour and farm activities and rehabilitation work following the natural disasters, etc. Carrying out heavy work and physical activities demands higher calorie needs and food intake.
Assessment of dietary intakes at individual levels provides most useful information on the nutritional adequacy of diets. Need to record all foods and problem of omission is lessened and foods are described more fully. Requires motivated and literate respondents, which can limit its use in developing countries; recording foods as they are eaten can also affect both the type of food chosen and quantities consumed. This is a weakness, when the aim is to measure the usual dietary intake. However, when the aim is to enhance awareness of the dietary behaviour change as in some intervention studies, this effect can be seen as a strength. This method is taken to represent the “gold” standard and is used as a reference for validation of other methods.
The validity of dietary recall has been studied by comparing reported intake with those recorded or weighed by trained observers. In general, group mean nutrient estimates from 24 hr recall were similar to observed intakes, although respondents with lower observed intake tended to over report and those with higher intakes tended to under report their past intakes. For some nutrients like VA with considerable variation in nutrient intake, there may be serious errors if one day recall is used to describe individual intakes. If groups are the focus of interest, the problem would be less.
Some of these errors are shared by all methods; for example the quality of the FCT on which rests the precision for the estimation of energy and nutrient intake. Other errors are specific to one or another of the methods. A larger number of errors are associated with FFQ, dietary history method while the weighed food record appears to be least affected.
The relationship between anthropometric and dietary energy inadequacy is not symmetric as ill health can cause growth failure in the presence of adequate food access. Food intake often will be reduced owing to poor appetite in sickness even in the presence of adequate food supply; however in a stable situation, people will not be of adequate body size with inadequate food energy even if health is good. The implications are illustrated in the table. Treating this association by placing individuals in categories depends crucially on the cut offs and implies that the cut off of – 2 z score for W/A used in the illustration is related to energy intake below requirement ( i.e hunger). In this case the cut off may be approximately correct. Crucially in a steady situation there should be no one in inadequate energy – adequate weight category (note bottom left cell is equal to 0). It is not possible to maintain an adequate weight with inadequate energy. This may help relate the indicators to each other to some extent, referring again to the table. DES indicators should go in the same direction as anthropometric indicators. Need for combination of methods support individual dietary intake surveys, including qualitative methods from HIES surveys and other HH surveys such as DHS and UNICEF – MICS surveys
Weight to height ratio is a simple and widely accepted method which estimates total body mass rather than fat mass. It correlates well with amount of body fat. BMI is BW in kg divided by the square of height in meters BMI of 25 -30 is an indication of being overweight and BMI above 30 indicates obesity