Spending long hours at work may make it harder to maintain a healthy weight, according to a new international study that links longer working hours with higher obesity rates.
Researchers say the connection may be explained by several possible factors: less time for physical activity, stress-related eating, higher cortisol levels and greater reliance on quick, calorie-dense food. But they stress that the findings show a statistical association only, not proof that long work hours directly cause obesity.
2 View gallery
Long work hours may make it harder to maintain a healthy weight
(Photo: MikeDotta/ Shutterstock)
“When people have a better work-life balance, their quality of life is better,” said Dr. Pradeepa Korale-Gedara of the University of Queensland in Australia, the study’s lead author. “They have less stress, they can focus more on nutritious food and they can incorporate more physical activity.”
The international study, presented this year at the European Congress on Obesity in Istanbul, compared working patterns and obesity rates in 33 OECD countries, including Britain, between 1990 and 2022.
According to the data, countries with longer annual working hours, including the United States, Mexico and Colombia, also reported higher obesity rates.
Even a small change in work hours was associated with a measurable difference. The study found that a 1% reduction in annual working hours was linked to a 0.16% decline in obesity rates.
The researchers emphasized that the relationship is complex and may be influenced by income levels, urbanization and other socioeconomic and cultural factors. Higher income levels, for example, were associated with lower obesity rates: a 1% increase in GDP per capita was linked to a 0.112% drop in obesity. A 1% increase in urbanization was associated with a 0.02% decline in obesity.
As of 2022, the United States had the highest adult obesity rate among 30 OECD countries included in the data, at 41.99%, while Japan had the lowest, at 5.54%. Chile, Mexico and New Zealand also recorded obesity rates above 30%, while several European countries, particularly in northern and western Europe, remained below 20%.
Britain fell between those extremes, with an obesity rate of 26.8%, one of the highest in Europe. About 3.8 million children in Britain ages 5 to 19 have a high BMI, roughly double the number of children with overweight or obesity in France and Italy.
“The findings suggest that the relationship between working hours and obesity is complex and influenced by different socioeconomic and cultural factors,” the researchers said. “These patterns point to possible mechanisms, such as less time for physical activity, increased work-related stress and greater reliance on prepared, convenient and calorie-dense food.”
They added that higher GDP per capita, greater urbanization and higher food prices were inversely associated with adult obesity rates, suggesting that better economic conditions, more supportive urban environments and relatively higher food costs may encourage healthier dietary choices.
The link between working hours and weight is also supported by other research. A broad meta-analysis published in Obesity Reviews, the official journal of the World Obesity Federation, reviewed a wide range of observational studies and also found evidence that long working hours are associated with negative weight outcomes and a higher risk of metabolic syndrome.
The authors of that review said addressing the health effects of workplace stress and prolonged sitting requires action from employers as well, including more flexible schedules and workplace programs that encourage employees to adopt a more active and healthier lifestyle.