WORKING long hours causes weight gain, research suggests — and knocking off early could help people slim down.

A study found that every one per cent reduction in working hours led to a 0.16 per cent cut in obesity levels.

Working long hours causes weight gain, research suggests — and knocking off early could help people slim down Credit: Getty

A study found that every one per cent reduction in working hours led to a 0.16 per cent cut in obesity levels Credit: Getty

And countries where people worked fewer hours tended to have fewer seriously overweight employees.

Author Dr Pradeepa Korale-Gedara said: “When people are busy, they tend to go for convenience food — and long hours could promote stress hormone cortisol, associated with weight gain.”

She also said it meant less time to exercise, while sedentary office jobs burn fewer calories.

The study of 33 developed nations, by Australia’s University of Queensland, found Brits were in the lowest ten for working hours, with an average of 1,505 per year — yet against the study’s trend were still the tenth fattest.

Colombians work the most, at 2,282 hours, and Germans the least, at 1,340 hours.

The findings suggest a four-day week could lead to 500,000 fewer obese Brits.

Obesity is a leading cause of cancer, heart disease and dementia.

James Reeves, of the 4 Day Week Foundation, said: “A four-day week on full pay could slash Britain’s obesity levels by giving millions the time they need to ditch bad habits and make healthier choices.”

Dr Christopher Snowdon, of the Institute of Economic Affairs, added: “The UK is among the ten countries in this study with the lowest working hours and yet has one of the higher obesity rates, so the idea that a four day week would make Brits slimmer seems dubious.

“For most people, a four day week would mean a lower income, and we know that people on low incomes are more likely to be obese.”

A Government spokesperson said: “This government will not mandate a four-day work week for five days’ pay.

“But through the Employment Rights Act, we’re making it easier for flexible working requests to be accepted.”