Measuring Healthy Diets to Advance Nutrition Globally Using the Diet Quality Questionnaire
This post is written by Chris Vogliano, technical advisor, USAID Advancing Nutrition.
One of my favorite things about my work in international development is the variety of foods that I have been able to experience around the world. Every country and even regions within countries have a unique flavor, which is great for adventurous eaters but challenging when trying to understand how shifting diet patterns in different regions of a country may be impacting nutrition. We know that assessing and monitoring positive and negative characteristics of diets is key to understanding the causes of poor health and nutrition outcomes. Identifying current diet patterns can help improve nutrition, especially in low- and middle-income countries where diets are rapidly changing due to urbanization, globalization, migration, and other factors. Measuring dietary patterns is an important first step that can inform nutrition programming and potentially both nutrition-sensitive agriculture policy and related interventions.
USAID Advancing Nutrition, the Agency’s flagship multisectoral nutrition project, is working with a diverse group of partners to support the adaptation of a Diet Quality Questionnaire (DQ-Q) across 92 countries, for adults as well as infant and young child feeding (ICYF). The DQ-Q was developed by the Global Diet Quality Project, a collaboration between Gallup, Harvard, and the Global Alliance for Improved Nutrition, with guidance from a technical advisory group of global experts in dietary assessment. Dr. Anna Herforth, principal investigator of the project at Harvard, has led development of the tool and is leading the adaptations across countries.
Diet Quality Data, Simplified
The DQ-Q is a new, easy-to-use tool to rapidly collect dietary data to measure diet characteristics needed to monitor and promote healthy diets at population level. The tool includes binary yes/no questions about consumption of 29 unique food groups, including both healthy foods and less healthy foods. The DQ-Q takes about five minutes to administer, is read the same way each time, and does not require implementers to have nutrition expertise or specialized training.
Demographics and Indicators
Population-level data obtained from the DQ-Q tool can be used to calculate numerous diet quality indicators, including the minimum dietary diversity for women, the corresponding food group diversity score, the Global Dietary Recommendation score, and the recently updated World Health Organization and UNICEF infant and young child feeding indicators.
Figure 1: Demographics and indicators of the DQ-Q tool
This tool can also be used to calculate the percentage of a population consuming foods from each of the 29 unique food groups, including healthy foods and foods associated with an increased risk of non-communicable diseases (i.e., unhealthy foods). A key innovation of the new tool is that the questions use closed lists, consisting of a limited set of sentinel foods for each food group.
Culturally Responsive and Inclusive Adaptations
The Global Diet Quality Project team has conducted more than 550 key informant interviews in over 92 countries to identify sentinel foods, the most commonly consumed foods in each food group for each country. The purpose of these country-specific adaptations is to ensure the DQ-Q tools are culturally responsive and representative of each country’s foodways, and to reduce food group classification errors. Key informants in each country identified not only the appropriate sentinel foods in each food group, but also their common names if they differ from common translations (such as “sukuma wiki” for “kale” in Kenya). In addition to the DQ-Qs for the general population, the project has adapted IYCF questions consistent with World Health Organization and UNICEF infant and young child feeding indicators (2021). This is the first effort to systematically adapt the list-based approach for food group level data collection, which is critical for high-quality, consistent data collection in the Demographic and Health Survey (DHS) and other national surveys.
Assessing Food Lists at the Subnational Level
Country adapted DQ-Q tools are designed to include foods commonly consumed in different regions and seasons within each country. Validation results conducted in Ethiopia, Vietnam, and Solomon Islands produced nearly the same results when the DQ-Q data were compared to a 24-hour multiple pass dietary recall. The Global Diet Quality Project, USAID, and USAID Advancing Nutrition are conducting additional validation studies of the country-adapted DQ-Q to assess the degree to which they capture foods commonly consumed among subnational populations in different countries.
Diet Quality Questionnaire Roll Out
The Gallup World Poll is already implementing the DQ-Q in 42 countries to assess diet quality, and aims to scale up implementation to all of the countries it surveys (about 140) by 2024. The map below (Figure 2) shows countries where the DQ-Q adaptations and data collection are underway. The DHS is also implementing question adaptations aligned with the DQ-Q for women of reproductive age and for IYCF.
Figure 2: Countries where the DQ-Q is being adapted, and implemented by the Gallup World Poll
All country-adapted DQ-Q tools will be freely available as a global public good by the end of 2021, and can be easily added to existing surveys to rapidly measure and monitor the diet quality of populations.