DIETARY DIVERSITY 101

Why are dietary diversity indicators considered a good choice for measuring effects of agricultural development programs on nutrition? The Gender-Nutrition Idea Exchange invites Marie Ruel, Division Director, Poverty, Health, and Nutrition, at the International Food Policy Research Institute, to explain.

Photo by Finn Thilsted. Source: Flickr (WorldFish, Nutrition and Health)

The observant reader will have noticed that we’re talking about dietary diversity (DD) indicators, plural. There are individual-level and household-level indicators. Some indicators have been developed and validated to measure dietary diversity in women 15-49 years old (the most commonly used indicator includes 9 food groups) and others have been developed for use with young children 6-23 months (based on 7 food groups; this indicator is included in WHO’s recommended set of indicators to measure infant and young child feeding practices). The household-level indicator, which was originally developed to measure food security, is based on 12 food groups. With that in mind, here’s the bottom line on dietary diversity indicators.

• • The individual-level ones (woman and child) are good indicators of diet quality because they are tightly associated with micronutrient adequacy of the diet (an important dimension of diet quality). In other words, the higher the DD score, the more likely the woman or child is to meet its daily micronutrient requirements (or to have a diet that helps meet their daily micronutrient needs). The positive association between DD and micronutrient adequacy has been tested for both women and young children respectively using a standard methodology and data sets from diverse developing country settings; and the results are robust and consistent. See our chapter in Diet Quality for a summary; special issue of Journal of Nutrition 2010, including a summary of findings for women’s DD from Arimond et al.; and the Working Group on Infant and Young Child Feeding Indicators.

• • The household DD indicator has not yet been tested for its performance in predicting micronutrient adequacy and should therefore not be used as an indicator of dietary quality at the household level, although it can be a useful indicator of food security. The household DD has been validated and shown to be a good indicator of household calorie consumption and total expenditure (a proxy for income), (see Hoddinott and Yohannes 2002), but it has not been validated for its performance at predicting diet quality or micronutrient content of the diet. One problem with the household DD indicator is that it includes food groups that provide mostly calories (cereals, oils, sugar) in addition to those that provide micronutrients such as dairy, fruits and vegetables, and meat, poultry and fish. This indicator was originally developed to reflect household food security and calorie consumption and is therefore not well suited to reflect diet quality in terms of micronutrient consumption or adequacy of intake. While it is possible to adapt the existing indicator (for example, by dropping the 3 food groups that do not contribute micronutrients or by imitating the 9 food groups used for the woman’s DD), the resulting re-designed household DD should be validated in order to determine whether or not it accurately reflects micronutrient adequacy at the household level across different contexts.

• • There is no doubt that DD indicators are associated with child nutrition outcomes, like stunting, underweight, and wasting, but it’s not the case everywhere. See results from our analysis of DHS data and other multi-country analysis, plus a summary in Diet Quality. Clearly, diet is only one aspect of what makes children grow and DD may not be the most pressing constraint in some areas, especially where rates of infections are very high. In these contexts, poor health may be a more important determinant of nutritional status than food insecurity.

For nutrition-sensitive agriculture development programs, including value chain interventions, using maternal DD indicators to track changes in diet quality makes sense. If information about children is of interest, using child DD indicators is more appropriate than using child nutritional status (anthropometric) indicators, because the child’s nutritional status does not depend only on food intake. The child’s anthropometry is affected by a variety of factors including food (quantity and quality), maternal feeding and caregiving practices (e.g., optimal breastfeeding and complementary feeding practices), and health (which in turn is determined by access to health, water, sanitation and hygiene services). In addition, young children generally consume very small amounts of the family diet and require special foods that have high concentrations of micronutrients such as specially fortified foods. For these reasons, large improvements in the amount and quality of food available at the household level as a result of successful agricultural development programs may be beneficial for adult family members, but may not always translate into significant improvements in young children’s nutritional status.

All and all it would be a mistake to make agriculture solely accountable for improving the nutritional status of young children during the first 1000 days window of opportunity because agriculture alone cannot provide all the necessary inputs to foster children’s growth and development. Agriculture needs to be complemented by investments in other sectors such as health, nutrition education, and water and sanitation, in order to achieve significant improvements in child nutrition. However, it is imperative to make agriculture accountable for improving the amount as well as the diversity and quality of food available and accessible to poor households and individuals throughout the lifecycle, including women during the 1000 days window of opportunity (pregnancy and lactation) and outside of it.

• • • Ruel, M.T., J. Harris, and K. Cunningham. 2013. “Diet Quality in Developing Countries.” In Diet Quality: An Evidence-Based Approach, Volume 2, edited by V.R. Preedy, L. Hunter, and V.B. Patel. New York, NY, US:  Humana Press.
    • Guidelines for measuring household and individual-level dietary diversity from FAO and from FANTA
    • Guidelines for measuring young child dietary diversity from WHO
    • Resources from the working group on infant and young child feeding indicators from FANTA

This post is part of a blog, the Gender-Nutrition Idea Exchange, maintained by the CRP on Agriculture for Nutrition and Health. To add your comments below, please register with Disqus or log-in using your Facebook, Twitter, or Google accounts. You must be signed-in or registered in order to leave a comment.