Could shorter working hours cut obesity rates?
People who work fewer hours each year appear to have a lower risk of obesity, according to an Australian study presented at the European Congress on Obesity in Istanbul, Turkey. The research shows that a 1% reduction in annual working hours is associated with a 0.16% decrease in obesity rates across OECD countries.
Food environments and time poverty are known to negatively affect nutrition and activity levels. While the association between work and obesity does not prove a causal link, the study – based on a large dataset from 33 OECD countries between 1990 and 2022 – puts the spotlight on links between working hours and exercise, diet and stress.
However, these connections have proven difficult to untangle. For example, energy and fat intake in Latin American countries in the OECD are far lower than European countries such as Norway, Spain, France, Denmark, and Austria, yet the Latin American countries have far higher rates of obesity.
The new work, led by Dr Pradeepa Korale-Gedara, University of Queensland, Brisbane, Australia, aimed to explore why obesity varies so dramatically among OECD nations. As of 2022, the United States reported the highest adult obesity rate among the 30 OECD countries with data at 41.99%, while Japan had the lowest at 5.54%. Several countries including Chile, Mexico, and New Zealand also exhibit high obesity rates, exceeding 30%, whereas several European nations, particularly in Northern and Western Europe, maintain rates below 20%, with the UK between these extremes at 26.8%.
Of the 32 countries with data analysed, the lowest working hours per year were Germany (1,340), Norway (1,422), Belgium (1,422), Sweden (1,436), and the Netherlands (1,450). The UK was in the lowest 10 countries, with 1,505, while the USA was in the 10 highest with 1,811. The five countries with the highest were Colombia with 2,282, Mexico (2,226), Costa Rica (2,149), Chile (1,966) and Israel (1,891).
Using computer modelling, the researchers found that between 1990-2022, a 1% reduction in annual working hours is associated with a 0.16% decrease in obesity rates across whole populations. When the data is divided by sex the impact of reduced working hours is stronger in men, where a 1% reduction in annual working hours is associated with a 0.23% decrease in obesity rates, compared with 0.11% for women.
‘These patterns point to potential mechanisms such as reduced time for physical activity, increased work-related stress, and greater reliance on energy-dense convenience foods,’ the authors say. ‘Higher GDP per capita, greater urbanisation, and higher food prices were negatively associated with adult obesity prevalence, suggesting that improved economic conditions, more supportive urban environments, and higher relative food costs may facilitate healthier dietary choices.’
They also note that extended working hours can induce psychological stress, contributing to stress-related eating and elevated cortisol levels, both of which are associated with weight gain.
‘This research underscores the critical role of working hours in shaping obesity rates across OECD countries,’ the paper says. ‘Future research should explore the interplay between work demands and health-related behaviours to better understand the complexities of obesity prevention.’
