Unhealthy diets are one of the largest drivers of noncommunicable diseases such as cancer, heart disease, and diabetes. Conditions linked to diet cause one-in-five deaths and half of all deaths of children under five, while costing trillions of dollars.
How can we ensure that everyone has access to nutritious food if we don’t understand what people are eating? Having a consistent, scalable way to measure diet quality globally is critical in order to shape relevant policies and guide funding to reach those most in need. The benefits impact everyone, with every dollar invested in healthy diets creating $12 in economic benefits.
In 2025, the United Nations added diet quality to its indicators for the Sustainable Development Goals (SDGs), key targets intended to improve health and education, spur economic growth, preserve the environment, and reduce inequity. The new indicator, called Minimum Dietary Diversity (MDD), tracks the food groups eaten by women and children. This data, which is measured using the Diet Quality Questionnaire, will be used to draw attention to and fight hunger and malnutrition.
The successful effort to include Minimum Dietary Diversity as an indicator in the Sustainable Development Goals was elevated by a 2022 convening at The Rockefeller Foundation’s Bellagio Center (Bellagio Center) to harmonize metrics for tracking diet quality. The convening brought together representatives from the World Health Organization (WHO), the Food and Agriculture Organization of the United Nations (FAO), and UNICEF, along with researchers and advocates.
Dr. Anna Herforth, principal investigator of the Global Diet Quality Project and who led the development of the Diet Quality Questionnaire, attended the 2022 convening. We spoke to her about why measuring diet diversity matters, how collaborators drove change at the international level, and what work still needs to be done to ensure everyone can access healthy food.
What gets measured gets managed. That’s why bringing diet quality into the UN Sustainable Development Goals is a monumental step forward for nutrition.
Dr. Anna HerforthPrincipal Investogator, Global Diet Quality Project
What is the new Minimum Dietary Diversity indicator, and why is it important?
What gets measured gets managed. That’s why bringing diet quality into the SDGs is a monumental step forward for nutrition. Before this, the Sustainable Development Goals (SDGs) tracked agricultural production, hunger, nutritional status, and noncommunicable diseases, but not the link between them, which is what people eat. Minimum Diet Diversity (MDD) helps us see that link. It is a proxy indicator for whether women and children are getting adequate nutrients. People who meet the minimum threshold are more likely to have a diet that contains adequate micronutrients.
The MDD indicator, which is now in the SDGs, shines a light on the issue and gives us a tool to educate and advocate for greater access to nutritious foods. If it shows that people aren’t consuming a diverse diet, it forces us to ask, “Why not?” The answer should spark important discussions about food availability and affordability and inform our agriculture and food policies, creating better social protections, improving incomes and wages, closing information gaps, and ensuring people have the opportunity to access healthy foods.
What is the Diet Quality Questionnaire and how does it help this work?
When I was at Cornell doing my PhD on international nutrition, a big part of our education was learning about the different kinds of data available to understand causes and consequences of malnutrition. We had indicators on nutritional status, infant and young child feeding practices, infectious diseases, and hunger. But when it came to data on what people actually eat and indicators of diet quality – there was nothing. It’s not really an easy topic to measure at scale. Approaches like asking someone to recall everything they’ve eaten over the past 24 hours or complex food-frequency questionnaires are valid when done well, but they’re expensive and difficult.
The Diet Quality Questionnaire (DQQ) was developed to overcome barriers to data collection that have precluded diet quality monitoring in the past. It is a simple, easy-to-use tool to measure minimum dietary diversity consistently across countries. The DQQ was developed by the Global Diet Quality Project – a collaboration between Gallup, Harvard T.H. Chan School of Public Health, and the Global Alliance for Improved Nutrition. Part of what makes it simple is that it asks about food groups using commonly-consumed foods. So instead of saying, “Yesterday, did you eat foods made from grains,” which can be hard for respondents to interpret, it might say “Yesterday, did you eat bread, rice, or pasta,” including food items that vary depending on the respondent’s country.
What happened at the Harmonizing and Mainstreaming Diet Quality convening at the Bellagio Center, and how did it help spark the creation of this new indicator?
The Bellagio Center meeting came just at the right time. It created a consensus that gave the extra push needed to make MDD a global indicator. One of the most important aspects was that it brought together the directors of nutrition of the FAO, WHO, and UNICEF. They’ve all worked together on nutrition issues before, but that was the start of a more formalized collaboration that carries on to this day, and it has been absolutely critical in moving this agenda forward. Along with them were people who work on gathering dietary data and other dietary assessment experts from a range of different countries. There was an important mix of aspirational goals and practicality. Dietary diversity is important, but healthy diets need to include moderation and balance. Attendees were in consensus that diet diversity shouldn’t be the only marker of a healthy diet, but they realized that, from a practical standpoint, MDD was an existing, validated option with the best chance of becoming an SDG indicator.
The MDD indicator could have been rejected as an SDG indicator, but the global community connected to it, to the point that it received more comments than any other proposal. That connection was a big reason why it succeeded. People from all over the world wrote and said, “This is a huge data gap. This information is really important, and we can measure it.” There was a need, and the indicator was adopted because that need was felt by so many people, many of whom were actively involved in adapting the DQQ for their country. Now, the new data will shift the discourse and policies about diet, nutrition, and public health in a way that was missing before.
Looking to the future of this work, what worries you, and what makes you hopeful?
Inequities and losses in biodiversity could cause more people to fall further into poverty, which would make it even harder to access diverse diets that meet their basic needs. I’m also concerned that increasing commercialization, expansion, and heavy marketing of ultra-processed foods around the world will displace nutrient-adequate foods while raising the risk of noncommunicable diseases. I hope that by keeping these challenges in mind, we can shift dialogues and drive action to improve dietary diversity, improve livelihoods for small farmers, and have some sort of limits on the ubiquity and the marketing of foods that make it harder for people to meet their needs and stay healthy.
What makes me hopeful is that the minimum dietary diversity indicator can draw attention to the issues of poor diets, lack of access to healthy diets, and people struggling to meet their basic needs. My vision is that the data we’re collecting will lead people to see this issue in a new light and spark action through programs and policies. There’s great work being done, both internationally and by governments and universities around the world, on how to shift policies so that they prioritize health along with economic growth. Indicators like MDD can help shift the consciousness and lead to action.
Herforth sees the consensus forged at the Bellagio Center and the progress it helped achieve as a testament to the power of authentic, human connection. “When people gather in person and establish real rapport, they call each other with questions. They see each other as resources and keep working together long after the meeting is done, “ she said. “Without that space, those connections are more theoretical. But meeting face to face manifests action.”
Learn More:
- Read about the UN’s Zero Hunger sustainable development goal.
- Watch Dr. Herforth discuss the importance of global food diversity and nutrition on the Food as Pharmacology podcast.
- Learn about the development of the Diet Quality Questionnaire.
While The Rockefeller Foundation provided support to the author to create this project, the Foundation is not responsible for the project and does not recommend or endorse the contents of the article.