Food security is often discussed in terms of whether people can afford enough groceries. But access to clean drinking water is also essential. Without it, preparing a safe meal can become difficult or impossible.
A global survey study published in Nature Food found that people who lacked clean drinking water were also more likely to go without food and experience food safety threats. The relationship appeared across countries at every income level, including wealthier countries such as the United States. Because the study captured people’s experiences at one point in time, it cannot show that a lack of clean water directly caused food insecurity. But the findings suggest that the two problems are closely connected and may be difficult to solve separately.
Researchers from the University of Southern California and the International Water Management Institute analyzed responses from 124,003 people in 121 countries. The data came from the Lloyd’s Register Foundation World Risk Poll, a global survey developed with Gallup.
Participants were asked whether they had gone without enough food to eat for more than a day during the previous year. They were also asked whether they had gone without clean drinking water for more than a day.
Across the world, people who lacked clean water were more likely to report that they also lacked food. People who experienced either problem, or both at the same time, were also more likely to report food safety threats and concerns.
The connection appeared in low-, middle- and high-income countries. The researchers found particularly strong combined effects on food safety in Eastern Africa and Northern America, a region that includes the United States and Canada.
“Even if you live in a wealthy country, if you lack access to clean drinking water, you are more likely to lack access to food,” lead author Wändi Bruine de Bruin said in a news release. Bruine de Bruin is a professor of public policy, psychology and behavioral science at USC.
The study did not identify a single explanation for the relationship. Instead, several factors may overlap.
Clean water is needed to wash produce, cook food and maintain safe conditions in the kitchen. When water is unavailable or unsafe, preparing meals can become more difficult. People may also need to spend additional time or money obtaining water, leaving fewer resources for groceries.
Broader pressures can contribute to both problems. Poor infrastructure, poverty, homelessness, extreme weather and conflict may make it harder for people to access safe water and enough food at the same time.
The study adds an important dimension to conversations about food insecurity. Hunger does not occur in isolation. Telling people to choose healthier foods or cook more meals at home has limited value when they do not have reliable access to clean water.
The findings should not be interpreted as a detailed picture of water insecurity in the United States. Although the survey included U.S. respondents and found the relationship in wealthy countries, the study did not provide a separate national estimate for Americans or identify which communities were most affected.
The survey also relied on self-reported experiences. It did not test household water quality, track what people ate or measure whether specific water or food programs improved health outcomes.
Still, the findings point to a practical reality: Access to food and access to clean water are closely linked. Efforts to improve nutrition and food safety may be less effective if water insecurity is treated as an entirely separate problem.
The study was supported by the Lloyd’s Register Foundation, the National Science Foundation, the Leverhulme Trust Foundation, the Reckitt Global Hygiene Institute and the IMMANA program, which supports research on agriculture and nutrition. IMMANA is led by the London School of Hygiene & Tropical Medicine in partnership with Tufts University and the University of Sheffield, with support from the United Kingdom government and the Gates Foundation.
The Lloyd’s Register Foundation also launched the World Risk Poll, the global survey used in the study, in collaboration with Gallup.