A huge international study has found that people who eat meals prepared outside the home are more likely to become overweight or obese, no matter where they live in the world.
The findings suggest that modern eating habits may be helping drive the global obesity epidemic at a much faster pace than expected.
The study was presented at the European Congress on Obesity (ECO 2026) and was carried out by researchers from Göttingen University and Heidelberg University in Germany.
Scientists examined health and food survey data from more than 280,000 adults across 65 countries to understand how eating outside the home affects body weight.
The research comes at a time when obesity rates are rising rapidly in both rich and poor countries. Around the world, people are eating more fast food, takeaway meals, restaurant dishes, and processed snacks than ever before.
At the same time, obesity-related diseases such as diabetes, heart disease, and high blood pressure are becoming increasingly common.
For decades, obesity was mainly seen as a problem in wealthy countries. But researchers say the situation has changed dramatically.
Many low-income and middle-income countries are now facing a double burden. Some people still struggle with poor nutrition and vitamin deficiencies, while others are becoming overweight because of easy access to highly processed food.
To better understand these global changes, the scientists analyzed surveys collected between 2009 and 2021. Participants reported how often they ate meals prepared outside the home during a typical week.
The researchers focused on food-away-from-home consumption, often shortened to FAFH. This includes meals from restaurants, fast-food outlets, cafés, street vendors, takeaway shops, and other commercial food businesses.
The study found that about 47% of adults worldwide eat meals outside the home at least once every week. But there were major differences between countries and regions.
In the Americas, eating out was extremely common. More than 80% of adults said they regularly consumed outside meals. In some lower-income countries, however, eating out was still relatively uncommon.
For example, in Timor-Leste, only about 12% of adults reported eating meals away from home at least once a week. In contrast, about 84% of adults in the United States said they ate outside meals regularly.
Even though eating out was less common in poorer countries, an interesting pattern appeared. People who did eat outside meals more often were much more likely to be overweight or obese.
The researchers found that adults living with obesity in low-income countries consumed outside meals at much higher rates than people with normal body weight. Similar patterns were seen in lower-middle-income countries.
Scientists believe this may happen because commercially prepared foods are often much richer in calories than traditional home-cooked meals. Fast food and restaurant meals frequently contain large amounts of oil, sugar, salt, and unhealthy fats. Portions are also often much larger than what people prepare at home.
These foods may encourage overeating because they are designed to taste highly rewarding and convenient. Busy lifestyles, urban living, work schedules, and food delivery apps may also make eating outside the home more attractive and more frequent.
The researchers also discovered that certain groups of people were more likely to eat out often. Younger adults, men, unmarried people, employed workers, and people with higher education levels tended to consume more meals prepared outside the home.
In low-income countries, eating out may still be seen as a sign of wealth or social success. In wealthier countries, however, outside meals have become part of normal daily life for many families.
The findings are important because they suggest obesity prevention cannot rely only on telling people to “eat less” or “exercise more.” Scientists say the wider food environment may strongly shape eating behavior.
Professor Sebastian Vollmer, one of the senior researchers, explained that modern food systems often make unhealthy eating easier than healthy eating. Highly processed foods are widely available, heavily advertised, and sometimes cheaper or more convenient than nutritious home-cooked meals.
The researchers say governments and public health experts may need to focus more attention on the food industry itself. Policies that encourage healthier restaurant meals, better food labeling, reduced portion sizes, and healthier school and workplace food options may help reduce obesity rates in the future.
At the same time, the scientists acknowledged several limitations in the study. Because the research was observational, it cannot prove that eating out directly causes obesity. Other factors, including exercise levels and lifestyle habits, may also contribute.
In addition, the food information was self-reported by participants, meaning some people may not have remembered their eating habits perfectly. The study also counted meals but did not fully measure how healthy or unhealthy each meal actually was.
Still, because the study included such a large number of people from many different countries, the researchers believe the findings provide strong evidence that eating outside the home is closely linked to obesity worldwide.
The research highlights how quickly food habits are changing across the globe. As cities grow and processed food becomes easier to access, home cooking may continue to decline in many societies.
Scientists say understanding these changes is important because obesity is not only a personal issue. It is also shaped by the way modern food systems are built. The study suggests that making healthier outside food more available could become a key strategy for improving public health in the future.
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Source: Göttingen University and Heidelberg University.
