How your cortisol levels are affecting your weight gain – and what you can do about it – The Independent

Research presented at the European Congress on Obesity in Istanbul on May 12, 2026, suggests a link between long working hours and increased obesity rates. The findings indicate that a 1 per cent reduction in annual working hours is associated with a 0.16 per cent reduction in obesity rates across the countries studied.

The data comes at a time when public health officials are concerned about weight trends in the United Kingdom, where approximately two-thirds of adults are categorized as overweight or living with obesity. This prevalence increases the risk of several serious health conditions, including stroke, heart disease, and Type 2 diabetes.

The Impact of the Office Environment

Researchers identified several environmental factors contributing to weight gain in professional settings. One primary explanation is the increasingly sedentary nature of modern jobs, which limits physical movement throughout the workday.

the availability of energy-dense foods within office environments often encourages poor dietary choices, further contributing to a calorie surplus for employees working long hours.

The Role of Cortisol and Stress

Beyond physical activity and diet, the biological impact of stress is a significant mechanism in this trend. Cortisol, known as the body’s primary stress hormone, is produced by the adrenal glands and plays a critical role in managing stress, fear, motivation, and mood.

Cortisol is essential for normal bodily functions, influencing sleep patterns, blood pressure regulation, and inflammation levels. However, chronically high levels of the hormone, often triggered by high-stress lifestyles and poor work-life balance, can influence weight gain.

While cortisol’s role in health is complex, some social media trends have popularized terms such as cortisol belly and cortisol face to describe inflammation and puffiness caused by stress. Experts cautioned that for the vast majority of people, these trending terms are not a primary medical concern.

Public Health and Policy Implications

The association between reduced working hours and lower obesity rates has led to renewed calls for the implementation of a four-day work week in the UK. Proponents argue that shorter work weeks could provide employees with more time for physical activity and better stress management.

The research suggests that by addressing the structural demands of the workplace, there may be a measurable impact on public health outcomes and a reduction in the prevalence of obesity-related diseases.

• A 1 per cent decrease in annual working hours correlates with a 0.16 per cent drop in obesity rates.
• Sedentary office habits and access to high-calorie foods are key environmental drivers.
• Chronic stress triggers cortisol production, which can impact metabolic health.
• Two-thirds of UK adults are currently overweight or obese.