This 13-page document provides guidance on the specific data collection needs for the household dietary diversity score (HDDS) indicator for food security, which the United States Agency for International Development (USAID) defines as follows: "when all people at all times have both physical and economic access to sufficient food to meet their dietary needs for a productive and healthy life." It has been developed by USAID's Food and Nutrition Technical Assistance (FANTA) project, which has supported a series of research initiatives to explore and test various methodologically rigourous indicators of the access component of household food insecurity (which includes availability, access, and utilisation). These indicators, it is hoped, can be used to guide, monitor, and evaluate - as well as report on - programme interventions that seek to enhance ability to acquire sufficient quality and quantity of food to meet all household members' nutritional requirements for productive lives.

Household dietary diversity is here defined as the number of different food groups consumed over a given reference period: "Knowing that households consume, for example, an average of four different food groups implies that their diets offer some diversity in both macro- and micronutrients. This is a more meaningful indicator than knowing that households consume four different foods, which might all be cereals." The following set of 12 food groups is used to calculate the HDDS: cereals, fish and seafood, root and tubers, pulses/legumes/nuts, vegetables, milk and milk products, fruits, oil/fats, meat/poultry/offal, sugar/honey, eggs, and miscellaneous.

Specifically, this process involves a face-to-face exchange of information - in the form of a series of yes or no questions - between a data collector and the person who is responsible for food preparation. The document is premised on the idea that these questions (which are detailed in Section III) will be part of a population-based survey instrument and will be applied to all the households in the sample at the time of both the baseline and final surveys. The authors argue that asking these questions takes less than 10 minutes per respondent. Furthermore, "Field experience indicates that training field staff to obtain information on dietary diversity is not complicated, and that respondents find such questions relatively straightforward to answer, not especially intrusive nor especially burdensome." It is possible to expand the questionnaire to capture programme-specific objectives (if, for example, a programme's activities encourage the consumption of specific foods or food groups); a sample strategy for doing so is presented in the first appendix.

The authors note that, while any increase in household dietary diversity reflects an improvement in the household's diet, changes in HDDS must be compared to a meaningful target level of diversity in order to use this indicator to assess improvements in food security in a performance reporting context; they offer two options for determining appropriate targets, one of which involves income/economic data from the baseline survey, and the other of which involves taking the average diversity of the 33% of households with the highest diversity.

The second appendix provides a side-by-side comparison of food groups included in the HDDS indicator, on the one hand, and the individual dietary diversity score (IDDS), on the other. IDDS is often used as a proxy measure of the nutritional quality of an individual's diet; the authors note that "If a program wished to collect data on HDDS and IDDS in the same instrument, data collection may become confusing because of the similarities of the questions. It is important to train the interviewers to help the respondent to transition from thinking about food groups consumed by the household to thinking in greater detail about the food groups consumed by their child."

Click here to access a related peer-reviewed summary on the Health e Communication website, and to participate in peer review.