When Dr. Pradeepa Korale-Gedara first noticed that countries like Japan and Germany—where people work fewer hours—also had some of the lowest obesity rates in the OECD, she wondered: could time at work be shaping our waistlines more than we think? Her new study, presented at the European Congress on Obesity in Istanbul, reveals a striking pattern across 33 wealthy nations: for every 1% cut in average annual working hours, obesity rates fall by 0.16%. This isn’t just a marginal correlation—it’s a consistent signal across three decades of data, and one that shifts how we think about public health.
Obesity affects over 40% of adults in the U.S., compared to just 5.54% in Japan, the lowest in the OECD as of 2022. For years, public health efforts have zeroed in on diet and exercise, but this study suggests a deeper, structural force: time poverty. With national data from the OECD, WHO, and World Bank, Korale-Gedara and her team at the University of Queensland analyzed trends from 1990 to 2022, controlling for income, urbanization, and even national fat intake—only to find that calories consumed didn’t align neatly with obesity rates. Countries like Chile and Mexico, despite lower average fat consumption than Norway or France, have far higher obesity levels.
The numbers paint a clear picture. Germany, with just 1,340 working hours per year, stands in sharp contrast to Colombia, where people average 2,282 hours—nearly 500 more. The U.S. logs 1,811 hours annually, placing it among the highest, while the U.K. sits at 1,505. The study found that shorter workweeks don’t just improve work-life balance—they’re tied to slimmer populations. The effect is especially strong for men: a 1% reduction in working hours links to a 0.23% drop in male obesity, compared to 0.11% for women. Over the earlier period, 1990–2010, the effect was even more pronounced, with men seeing a 0.24% decline and women a 0.17% decline per 1% cut in hours.
What’s particularly telling is how the relationship has shifted. Between 2000 and 2022, the overall effect weakened slightly to a 0.13% obesity reduction per 1% drop in work hours, with women now showing a stronger response (0.17%) than men (0.12%). This could reflect changing gender roles, greater female workforce participation, or evolving lifestyle pressures. Whatever the cause, the message is clear: time is a health resource.
As countries grapple with rising healthcare costs and declining well-being, this study offers a bold insight: sometimes, the best prescription isn’t a new drug or diet, but more hours in the day. The path to healthier populations may not run through gyms or grocery labels—but through labor policy.