Individual Dietary Diversity Score

Outcome

the average number of defined food groups consumed during the previous day and night by [specify the target group]

The indicator measures the average number of defined food groups eaten by the target population during the previous day and night. It provides a snapshot of dietary diversity and, where the score has been validated for the population, can be used as a proxy for nutrient adequacy. It does not measure food quantities, energy or nutrient intake.

Collect the following data by conducting individual interviews with a representative sample of your target group members. If assessing children, interview the caregiver who is most knowledgeable about what the child ate and drank.

1) Check whether yesterday was a special day, such as a religious festival or celebration, when an unusually varied or limited diet was eaten. If so, follow the approach agreed for the survey, such as excluding the recall or flagging it for separate analysis.

2) List all foods and drinks the person consumed during the previous day and night in the Recording Meals Form, including meals, snacks and foods consumed outside the home.

3) Double-check the composition of meals and mixed dishes, including their ingredients (e.g. whether porridge contained milk).

4) Check for any snacks, fruits, drinks or other foods that were not mentioned.

5) Only then record in the questionnaire which food groups were consumed. Double-check with the respondent regarding food groups that were not mentioned (for example: Did she eat any eggs yesterday?)

6) Count the number of food groups consumed to calculate the Individual Dietary Diversity Score.

7) Calculate the indicator's value by adding all individual dietary diversity scores and dividing the total by the number of respondents with valid dietary data.

This data can be disaggregated by age group, sex, geographic area and household wealth category, and, if relevant, also by displacement status.

1) Individual dietary diversity is prone to seasonal differences. Do your best to collect baseline and endline data in the same period of a year; otherwise it is very likely that they will not be comparable. Do not collect data during the fasting periods (such as pre-Easter time or Ramadan) and during the fasting days. 

    

2) This indicator relies on an accurate age assessment. Since people often do not remember the exact dates of their children’s birth, the data collectors should always verify the child’s age. This can be done by reviewing the child’s birth certificate, vaccination card or another document; however, since many caregivers do not have such documents (and since they can include mistakes), it is essential that your data collectors are able to verify the child’s age by using local events calendars. Read FAO’s Guidelines (see below) to learn how to prepare local events calendars and how to train data collectors in their correct use.

 

3) For children 6–23 months of age, WHO guidance uses 8 food groups, including breast milk. The original WHO 2010 guidance used 7 food groups, but this was updated in 2017 to include breast milk as an 8th food group. For other age/sex groups, there is no universally agreed number of food groups for IDDS. The FAO guidance proposes 9 food groups specifically for the Women’s Dietary Diversity Score and notes that scores for other age/sex groups can be developed from the standard questionnaire according to the needs of the study.

   

4) Record food groups in the questionnaire only after all meals were listed in the Recording Meals Form – never record it straightaway as it is very likely that the number of food groups consumed will be under-reported.

  

5) When training your data collectors, practice extensively which meals belong to which food group (allocate at least 3 hours full of examples and exercises). For example, while pumpkin flesh belongs to Vitamin A Rich Foods, pumpkin leaves belong to Dark Green Leafy Vegetables (see more examples in the FAO Guidelines below). If your questionnaire includes examples of different foods per each group, adjust them to the local context. Before data collection, adapt the food lists to locally available foods and commonly used food names, translate the questionnaire into the languages used by respondents, and field-test it.

    

6) Decide before data collection how foods consumed in very small quantities will be treated and apply the same rule consistently. FAO reports that, in validation research among women aged 15–49 years, excluding foods consumed in amounts of about one tablespoon or less (<15 g) improved the association between dietary diversity and micronutrient adequacy. This threshold should not automatically be applied to other population groups.

  

7) Take advantage of the very useful guidance written by FAO - access below.

Also consider using the following indicators:

• Minimum Dietary Diversity - Women (use when measuring standardised dietary diversity among women of reproductive age)

• Minimum Dietary Diversity - Children (use for children aged 6–23 months rather than applying a generic IDDS score)

• Household Dietary Diversity Score (complements IDDS by assessing dietary diversity at household level as a proxy for food access)