The Food Prices for Nutrition project shows how the cost and affordability of healthy diets can be used to monitor food access and guide intervention. Our methods start with data on availability and price that is routinely collected around the world. We match item descriptions to food composition, and measure access to healthy diets using the least expensive locally available items that would meet national guidelines and global targets. Our project supports the work of national governments, international organizations, and educational institutions, leading to large-scale adoption and use of these metrics.
Our mission is to equip governments and civil society with accurate, updated metrics to monitor the cost and affordability of healthy diets, for use in guiding agriculture and food system change. We envision a global food system that brings healthy diets within reach of all people at all times.
Our data and methods generated the FAO, IFAD, UNICEF, WFP and WHO’s estimate that about 2.8 billion people cannot afford a healthy diet, as published in their SOFI annual reports and used to frame the summary statement of action from the 2021 UN Food System Summit. For global monitoring, our core result is the Cost and Affordability of a Health Diet database, published jointly by the FAO and the World Bank. Within countries, we provide the tools for national governments and others to monitor food access for diverse local populations, such as the Ethiopian Public Health Institute (EPHI) and Nigeria’s National Bureau of Statistics (NBS).
Why this project?
Our metrics help identify the causes of poor diet quality
This project’s diet cost metrics can help identify actions to improve nutrition by distinguishing among three possible causes of poor diet quality:
- high prices for the least expensive items needed from each food group, thereby revealing opportunities to improve diet quality through supporting production and distribution;
- insufficient income available to buy the least expensive healthy diet using locally available foods, thereby revealing the need for higher earnings or safety nets and social assistance; and also
- displacement of healthy foods by less nutritious items, even when low-cost healthy diets would be affordable, thereby revealing the need to address food choice among available options whose health effects may be unknown or misleading, as well as costs of meal preparation or other factors that affect food choice.
A recent summary of our methods and results is this 20-min. explainer video from a talk for U.S. audiences at the National Academies, with more details available from our publications and outreach through diverse media and worldwide events.
Food prices create a ladder of affordability
When healthy diets are unaffordable, food prices relative to available income are an insurmountable barrier to reaching international standards of diet quality. Among affordable diets, many other factors also influence food choice, but even the least expensive items for each step up in diet quality are have a higher cost per day:
Our work combines existing datasets to measure the cost and affordability of each step up in diet quality, based on the retail consumer prices and nutritional composition of items available in local markets. The resulting metrics provide an operational measure of access to healthy diets, for use in monitoring the food and nutrition security of vulnerable populations.
The diet cost metrics we use, as summarized on the methods page, are based on identifying the least expensive locally available foods in sufficient quantities to meet a population’s nutritional needs. Results have been widely disseminated in peer-reviewed journal articles and dialogue with international agencies and national governments, beginning with work in Ghana and Tanzania (AJAE 2018) and practical use to guide agricultural, food and nutrition policy is being scaled up globally through UN system agencies, country governments and the World Bank (https://www.worldbank.org/FoodPricesforNutrition).
For international comparisons, our core discovery is illustrated by the figures below from the first round of global monitoring data for 2017, and the updated results for 2021:
Results shown above reveal some variance in the Cost of a Healthy Diet but no correlation with national income, while actual food spending is generally higher at higher income levels. For the world’s lowest-income people, resources available for food and hence actual food spending are lower than even the least expensive locally available healthy diets, while higher-income people may not obtain healthy diets even though they spend more on food. Use of the lowest-cost diet as a benchmark allows national governments and international organizations to distinguish the causes of poor nutrition as either lack of access due to high prices or low incomes, or displacement of low-cost healthy diets by other foods due to factors such as time use or tastes and aspirations. This diagnostic metric helps identify locally-appropriate interventions to improve access through innovations and investment in food supply to lower cost, safety nets and livelihoods to raise income, or other actions to alter food choice from among the affordable options, and thereby achieve universal access and use of healthy diets worldwide.
How we work
The goals of Food Prices for Nutrition are summarized below:
Funding and origins of our work
Food Prices for Nutrition (INV-016158) is a five-year, $3.8 million effort from Oct. 2020 through Aug. 2025 funded by the Bill & Melinda Gates Foundation and the Foreign, Commonwealth and Development Office of the UK government, implemented by Tufts University. The first four years were conducted in partnership with the World Bank, the International Food Policy Research Institute (IFPRI), and diverse collaborators in Bangladesh, India, Pakistan, Burkina Faso, Ethiopia, Ghana, Malawi, Nigeria, Tanzania and other countries around the world. Our work aims to scale up the use of methods developed through two previous projects at Tufts University: first Indicators of Affordability for Nutritious Diets in Africa (IANDA, 2015-17), a £250,000 research grant funded by UKAid through the IMMANA project, followed by Changing Access to Nutritious Diets in Africa and South Asia (CANDASA, 2017-20), an $800,000 research grant funded by the Bill & Melinda Gates Foundation for work in India, Bangladesh, Ethiopia, Ghana, Malawi, Tanzania and elsewhere. Project-related activities at Tufts University have also been funded by contracts from the Food and Agricultural Organization of the United Nations for background papers to the SOFI 2020, 2021 and 2022 reports and related policy analyses, and received additional support from USAID through the Feed the Future Innovation Lab for Nutrition and the Feed the Future Policy Research Consortium, for work in Malawi and elsewhere. The project’s activities at IFPRI build on a project funded by the Bill & Melinda Gates Foundation entitled Advancing Research on Nutrition and Agriculture (ARENA), and our work at the World Bank is part of its Development Data Group building on the International Comparison Program (ICP).
NEWS AND CONVERSATION
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