New research presented at this year’s European Conference on Obesity (ECO 2026) in Istanbul, Turkey (12-15 May) shows that a 1% reduction in annual working hours is associated with a 0.16% reduction in obesity rates across OECD countries. The study was led by Dr. Pradeepa Korale-Gedara and colleagues at the University of Queensland in Brisbane, Australia.
Adult obesity remains a major public health challenge across OECD countries, with significant health, social and economic implications. Public health research has overwhelmingly focused on dietary patterns, activity levels, and individual behavior as causes of obesity. While this has led to significant advances in knowledge in many areas such as nutrition, human metabolism, and psychology, researchers are increasingly focusing on structural determinants to develop effective interventions. Food environment and time poverty have long been understood as factors that negatively impact nutrition and activity levels, and the role of working hours as a factor in obesity has become more prominent in recent years.
In this new study, the authors investigated the association between working hours and obesity rates in terms of a broader range of determinants compared to existing research using data from 33 OECD countries over the period 1990-2022.
Preliminary analysis of the dataset surprisingly showed that average energy and fat intakes reported at the country level were not well correlated with national obesity rates. For example, obesity rates in Latin American countries are much higher, even though their energy and fat intakes are much lower than in European countries such as Norway, Spain, France, Denmark, and Austria.
The prevalence of obesity varies widely across OECD countries. As of 2022, the United States has the highest adult obesity rate among the 30 OECD countries at 41.99%, while Japan has the lowest at 5.54%. Some countries such as Chile, Mexico and New Zealand also have high obesity rates of over 30%, while several European countries, particularly Northern and Western Europe, maintain obesity rates below 20%, with the UK falling between these extremes at 26.8%.
As of 2022, the lowest annual working hours of the 32 countries whose data was analyzed were Germany (1340 hours), Norway (1422 hours), Belgium (1422 hours), Sweden (1436 hours), and the Netherlands (1450 hours). The UK was in the bottom 10 countries with 1,505 cases, and the US was in the top 10 with 1,811 cases. The five countries with the most cases were Colombia (2,282 cases), Mexico (2,226 cases), Costa Rica (2,149 cases), Chile (1,966 cases), and Israel (1,891 cases).
To account for potential gender-specific effects, analyzes are conducted separately for men and women. Additionally, subsample analyzes were performed for the periods 1990–2010 and 2000–2022* to assess how the relationships between factors evolved over time. Data is obtained from publicly available sources such as OECD, WHO, FAO, and World Bank.
Using computer modeling, researchers found that a 1% reduction in annual working hours between 1990 and 2022 was associated with a 0.16% reduction in obesity rates across the population. When the data are broken down by gender, the impact of shorter working hours is stronger for men: a 1% reduction in annual working hours is associated with a 0.23% reduction in obesity rates, compared to 0.11% for women.
The effect of working hours on obesity was shown to vary by period. Looking at the initial period of the study, 1990 to 2010, a 1% decrease in annual work hours would reduce overall population obesity rates by 0.17%. When assessing men and women separately, this reduction in work hours was associated with a 0.24% decrease in obesity rates among men and a 0.17% decrease in obesity rates among women.
An analysis of the period from 2000 to 2022 shows that a 1% decrease in working hours was associated with a 0.13% decrease in obesity rates across the population. A 1% decrease in work hours over this period was associated with a 0.12% decrease in obesity rates among men and a 0.17% decrease in obesity rates among women.
The authors say these results indicate that the effect of working hours on obesity was more pronounced in the earlier period (1990-2010) than in the recent past. They believe that policy interventions and increased public health awareness may have contributed to the decline in obesity rates since 2000. The literature also supports this explanation. In addition, changes in social norms may also be at play. As obesity rates increase, increased cultural awareness and promotion of healthy behaviors regarding nutrition and exercise may have offset some of the factors driving obesity rates.
Higher income levels were also associated with lower obesity rates, with a 1% increase in GDP per capita associated with a 0.112% decrease in obesity (0.16% for men and 0.11% for women). Urbanization also has an impact, although the impact is small. A 1% increase in urbanization (percentage of population living in urban areas) was associated with a 0.02 decrease in obesity (for both men and women). However, these associations are nonlinear, and factors related to differences in national culture and infrastructure play an important role.
The authors write: “These patterns point to potential mechanisms such as decreased physical activity time, increased work-related stress, and increased reliance on energy-dense ready-to-eat foods. Rising GDP per capita, increasing urbanization, and rising food prices are negatively correlated with adult obesity rates, suggesting that improved economic conditions, more supportive urban environments, and higher relative food costs may promote healthier dietary choices.”
Regarding the overall results, they said: ”The findings suggest that the relationship between working hours and obesity is complex and influenced by a variety of socio-economic and cultural factors. Long working hours create time constraints that can lead to unhealthy food choices and reduced physical activity. As previously mentioned, long working hours can also induce psychological stress, which can contribute to stress-related eating and elevated cortisol levels, both of which are associated with weight gain.”
“These results highlight the need for coordinated policy responses that go beyond individual behavior change. Effectively addressing obesity requires an integrated approach that considers labor market dynamics, urban design, and food system governance. Policy interventions aimed at improving work-life balance, promoting active transportation, and promoting healthier food environments may play an important role in reducing obesity risk.”
They conclude: ”This study highlights the important role that working hours play in shaping obesity rates across OECD countries. We advocate for policies that prioritize public health, such as regulating working hours, increasing vacation entitlements, and promoting healthier food environments. Future research should investigate the interaction between job demands and health-related behaviors to better understand the complexity of obesity prevention.”
sauce:
European Obesity Research Association
