Three Billion People Cannot Afford Healthy Diets. What Does This Mean for the Next Green Revolution?

The Reset the Table essay series is published weekly, describing today’s challenges to global food security and proposing U.S. government responses.

Three billion people cannot afford the cheapest form of a healthy diet. This appalling number reveals a core cause of malnutrition in all its forms. It was published in the United Nation’s 2020 State of Food Security and Nutrition in the World report, which is perennially focused on hunger, or lack of sufficient of calories. This year for the first time, the report includes a statistic squarely focused on whether people can access food to meet dietary needs, or the nutritional quality of those calories. It shows that although hunger is a problem, more than four times as many people cannot access healthy diets. What that means is that food security eludes many more people than previously thought.

“Access by all people at all times to sufficient, safe, nutritious food that meets dietary needs for a healthy and active life” is the global vision for food security the United Nations has used since 1996. But it has not fully been realized, in part because we have been sidestepping the issue of access to nutritious food.

Food to meet dietary needs is a concept handily captured by food-based dietary guidelines, including the U.S. Dietary Guidelines for Americans (My Plate) and guidelines likewise published by many other countries. I led the analysis that found that to follow these recommendations, people would need to spend an average of approximately $3.75 in international dollars per day at a minimum, selecting the cheapest options available in each different country.

Our analysis found that a significant proportion of the world’s population—over 40 percent, primarily located in Africa and South Asia—simply do not have $3.75 to spend on food every day. This amount is far above the international poverty line of $1.90. The cost of purchasing just enough of a basic starchy staple food to survive the day is about five times less than purchasing a healthy diet. Quite predictably, people in poverty around the world are eating diets mainly consisting of starchy staple crops, such as rice, corn, or wheat.

The most affordable diet is composed of these crops, which have received the lion’s share of public investment over the last 50 years. Public investment works: where the money goes, innovations follow, and agricultural supply chains have shifted to produce more of these three crops. As supply increases, these starchy staples have become cheaper and constitute a greater proportion of global diets.

The Green Revolution dramatically improved yields for cereals, and it is often claimed that the world has enough food to feed everyone. That is only partly true, however. Yes, there are enough calories available so that no one would have to go hungry, but there are not enough of the other foods needed for healthy diets. Only in Asia are there sufficient fruits and vegetables available per person per day, for instance. If we think about “food” in terms of diverse foods, we have to think about improving both availability and affordability of a wider range of healthy foods.

Of the $3.75 needed for a healthy diet, fully $1.50 is for fruits and vegetables. The World Health Organization recommends these be consumed in the amount of at least 400 grams per day, advice echoed in most national dietary guidelines, as perhaps the single most widely accepted core component of a healthy diet. And the lack of fruits and vegetables in diets is among the largest contributors to the global burden of disease. That is, diets low in fruits, vegetables, and other healthy primarily plant-source foods are estimated to be the leading cause of illness and premature death.


Fruits and Vegetables in Numbers

  • One hundred percent of dietary guidelines, such as the Dietary Guidelines for Americans and analogous guidelines published in other countries, recommend consumption of abundant fruits and vegetables.

  • Fruits and vegetables are emphasized due to their nutrient content and their association with lower rates of diet-related noncommunicable diseases. It is estimated that 39 percent of all diet-related deaths globally are attributable to low fruit and vegetable intake.

  • Nearly 43 percent of people in the world cannot afford healthy diets, which are those that follow food-based dietary guidelines. In low-income countries, 87 percent of people cannot afford healthy diets. Approximately 40 percent of the cost of a healthy diet is fruits and vegetables.

  • It is estimated that 82 percent of people in low- and middle-income countries do not consume enough fruits and vegetables (400 grams per day, equivalent to five a day).​

  • The world produces only 35 percent of the fruits and vegetables needed for all people to meet the global recommendation (400 grams per person per day).

  • Approximate percent of public agriculture investment devoted to vegetables: 2 percent.1


If we are serious about healthy diets for all, where is public investment in fruits and vegetables? The cost of vegetables and fruits in Africa and Asia appears to be increasing relative to other foods. In many countries I have visited, particularly in Africa and South Asia, farmers struggle with the risks involved in growing vegetables, which are highly profitable if they are grown, due to three main factors: low-quality seed, pest and disease stress, and inadequate cold chains or market linkages. What is public investment in agriculture doing about vegetable seeds and rural cold chains? Or about diversity in vegetables and fruits important for local use, such as traditional or indigenous vegetables, and not only horticulture as an export business? Or about food safety related to significant (often well-justified) consumer concerns about contamination and adulteration?

The entire budget of the World Vegetable Center, the primary global institution focused on these issues, is a mere 2 percent of that of the CGIAR, a global partnership for food security research.2 The 2020 combined budget for maize, wheat, rice, and starchy tubers alone is 30 times that for vegetables. Adding a geopolitical conundrum, the World Vegetable Center is not a member of the CGIAR—and therefore cannot access a large tranche of agricultural research funding and other opportunities—because it is headquartered in Taiwan, which is not recognized by China, an influential member of the CGIAR system. All this to say, the public agriculture investment architecture has not prioritized vegetables.

The global priorities for agricultural R&D are related to training opportunities and programs. U.S. land-grant universities train plant breeding scientists every year focused on the same big crops. There are entire graduate programs focused on a single species (maize, rice, wheat, potatoes), but few students of horticulture, which covers a vast diversity of species. The tracks lead straight from training and into institutions that have not kept up with global demand and global need for diverse diets. The public system of education designed to ensure support to farming where needed has gotten in a rut. Something needs to shift.

It might be tempting to say that private companies can take care of fruits and vegetables. But they have not. Companies can generally make a greater profit from ingredients destined for highly processed foods, which do not typically include much in the way of fruits and vegetables. Big companies that deal with horticulture are also more focused on high-profit export markets than food security and are likely to be more focused on standardization than locally adapted diversification.

The next Green Revolution should focus on crops that are severely lacking in both diets and public investment, including training as well as research and development. Smart investments in programs like U.S. Agency for International Development’s Feed the Future or the Horticulture Innovation Lab can do more to amplify diversity rather than narrow it. Governments can also support global and regional institutions focused on foods that are missing in diets, including national horticultural research institutes. The World Vegetable Center needs to be recognized at the global table, and other regional and national programs on fruits, vegetables, and legumes similarly need more support. Public programs like Feed the Future should pivot toward under-researched and underutilized nutritious crops. Land-grant universities need to train a next generation of agronomists and breeders in horticulture.

Overall, investment in crops should bear some resemblance to the balance of foods humans need for healthy diets. A greater diversity needs to be tended so that we create a world where there are not only enough calories for all, but where all people can afford healthy diets.

Anna Herforth is a Tufts affiliate, a senior research associate at the Department of Global Health and Population at the Harvard Chan School of Public Health, and a leader of the Agriculture-Nutrition Community of Practice (Ag2Nut).

Commentary is produced by the Center for Strategic and International Studies (CSIS), a private, tax-exempt institution focusing on international public policy issues. Its research is nonpartisan and nonproprietary. CSIS does not take specific policy positions. Accordingly, all views, positions, and conclusions expressed in this publication should be understood to be solely those of the author(s).

© 2020 by the Center for Strategic and International Studies. All rights reserved.

1World Vegetable Center budget of $18 million compared to CGIAR budget of $849 million, calculated from budgets available here and here.

2 Ibid.

Tufts Affiliate; Senior Research Associate, Department of Global Health and Population, Harvard Chan School of Public Health; Leader, Agriculture-Nutrition Community of Practice