Measurement and Interpretation TRAINING COURSE ON ASSESSMENT OF NUTRITIONAL STATUS, National Food Policy Capacity Strengthening Programme (NFPCSP) 21 December 2011 Presentation by: Nusha Choudhury, WFP
Measuring Dietary Diversity The gold standard to measure dietary diversity is through measuring various food items consumed by an individual or a household in energy or kilocalorie terms. Costly Time consuming Requires Technical expertise Alternate/Proxy Indicators Household/Individual Diet Diversity Score/HDDS/IDDS Food Consumption Score/FCS
Household & Individual Diet Diversity Score (HDDS/IDDS) Measures no. of different food groups consumed over a given reference period i.e. 24 hours/1 day (FANTA/USAID). HDD is also a proxy for hh’s socio economic status. Whereas IDD is purely a proxy measure of an individual’s quality of diet. 12 Food Groups in HDD, (Score: 0-12) 1.Cereals Roots and tubers 2.Vegetables 3.Fruits 4.Meat, poultry, offal 5.Eggs 6.Fish and seafood 7.Pulses/legumes/nuts 8.Milk and milk products 9.Oils/ fats 10.Sugar/honey 11.Miscellaneous 8 Food Groups in IDD (Children), (Score: 0-8) 1.Grains, roots or tubers 2.Vitamin A-rich plant foods 3.Other fruits or vegetables 4.Meat, poultry, fish, seafood 5.Eggs 6.Pulses/legumes/nuts 7.Milk and milk products 8.Foods cooked in oil/fat
General Rules for HDD & IDD Data Collection Data should be collected during the food shortage period of the year. Recall period is 24 hours. The 24 hour recall period has to be a normal/usual food consumption day for the household/individual. Generally for HDD food items consumed outside the house should not be included, unless it is a common practice for majority of the household members.
HDDS Calculation Step 1: Assign 1 if the food group/item consumed; 0 not consumed. Sum all the scores for various food groups. Sum will be between Step 2: The average HDDS for the sample population Sum HDDS Total no. of households Setting HDDS Threshold: Option 1: From a baseline survey take the HDDS for the richest income tercile (33%). Option 2: From a baseline survey take HDDS of the upper tercile (33%) of diet diversity.
Food Consumption Score FCS is a frequency weighted diet diversity score for a household or an individual over past 7 days. Here the score is calculated using the frequency of consumption of different food groups by (WFP). Key features of FCS Total 9 food groups are considered. Consumption frequency by various food groups are recorded over 7 days recall basis. Consumption less than 10 grams/1tea spoon are not considered. Each food groups are assigned weights based on their micro and macro nutrient content. Key features of FCS Total 9 food groups are considered. Consumption frequency by various food groups are recorded over 7 days recall basis. Consumption less than 10 grams/1tea spoon are not considered. Each food groups are assigned weights based on their micro and macro nutrient content.
Food Groups & Weights in FCS FOOD ITEMS (examples) Food groups (definitive) Weight (definitive) 1 Rice, wheat, maize, maize porridge, sorghum, millet pasta, bread and other cereals Main staples2 Cassava, potatoes and sweet potatoes, other tubers, plantains 2Beans. Peas, groundnuts and cashew nutsPulses3 3Vegetables, relish and leavesVegetables1 4FruitsFruit1 5Beef, goat, poultry, pork, eggs and fishMeat and fish4 6Milk yogurt and other diaryMilk4 7Sugar and sugar productsSugar0.5 8Oils, fats and butterOil0.5 9 spices, salt, fish power, small amounts of milk for tea. Condiments0
FCS Calculation Group all the food items into specific food groups. Sum all the consumption frequencies of food items of the same group, and recode the value of each group above 7 as 7. Multiply the value obtained for each food group by its weight and creates new weighted food group scores. Sum the weighed food group scores, thus creating the food consumption score (FCS). Using the appropriate thresholds (see below), recode the variable food consumption score, from a continuous variable to a categorical variable. FCSProfiles 0-21Poor Borderline > 35Acceptable
Bangladesh Specific FCS Given the importance of oil and fish in the diet of the Bangladeshi people, the general thresholds were elevated. As a result, FCS thresholds were revised for Bangladesh (HFSNA 2009): Poor consumption (≤28), Borderline Consumption (>28 and ≤42), Acceptable Consumption (>42), An additional threshold was introduce to distinguish the acceptable households between acceptable low (43-52) and acceptable high (>52).
Diet Composition by Food Consumption Score in Bangladesh
Comparative Advantages of the Two Scores HDD has more food groups than FCS therefore prevents under reporting. Short recall periods are more reliable. Easy to collect, enumerators do not need extensive training. More suitable for rapid assessments during emergencies. A child IDD module is available. FCS records frequency of consumption which prevents over reporting. 7 days recall period provides a habitual food consumption. Disregards small quantities of consumption which over rates the consumption. Suitable for in depth food security assessment.
Research findings on the two scores Gina Kennedy et al. conducted a study in Burkina Faso, Lao PDR, N. Uganda and found correlation between HDDS & FCS were significant in all three countries. The best correspondence identified based in this study FCS ≤ 21 corresponded to HDDS between 2 & 3. FCS ≤ 35 corresponded to HDDS slightly higher than 3. FCS and HDD demonstrated similar strength of correlation with other food security indicators. Gina Kennedy et al. conducted a study in Burkina Faso, Lao PDR, N. Uganda and found correlation between HDDS & FCS were significant in all three countries. The best correspondence identified based in this study FCS ≤ 21 corresponded to HDDS between 2 & 3. FCS ≤ 35 corresponded to HDDS slightly higher than 3. FCS and HDD demonstrated similar strength of correlation with other food security indicators. IFPRI research found that combination of frequency and diversity in FCS correlates better with household energy intake than only diet diversity (based on three countries) Another IFPRI research revealed that weighted FCS do not have added advantage over un weighted FCS in terms of relationship to energy intake, unless they are locally adjusted.
Research findings on linkage between FCS & anthropometric measures P <0.05P <0.001P <0.000 HFSNA 2009
Precautionary messages Both the FCS and HDDS are proxy indicators of food consumption and are not interchangeable. The choice of the methods will depend on objective and depth of the surveys. None of these measures are directly synonymous of food insecurity, they are rather one of the indicators of food insecurity. To identify the food insecure and vulnerable the diet diversity scores/groups should be used in combination with food security access indicators like income, expenditure, asset, HFIAS etc.
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