• physical exertion
• public health
• health promotion

Overweight and obesity are increasingly prevalent in high-income countries, with societal shifts towards sedentary living and poorer quality diets regarded as major contributors to an energy imbalance of increased energy intake and reduced energy expenditure.1 By focusing on the ‘energy expenditure’ side of the energy balance equation, studies suggest that increasing physical activity (PA) levels can be an effective strategy to prevent or minimise weight gain in adults.2 Occupational PA can be an important intervention target as most adults will participate in the labour market at some point of their lives and can spend a third of their day or more at work.

There is mixed evidence for the association between occupational PA and changes in weight gain. It also is unclear whether reverse causation is a possibility, that having a higher weight at baseline is related to a risk of later occupational physical inactivity. The study by Sagelv et al 3 helps fill this research gap. The study of 11 308 participants assessed over three or more consecutive follow-up periods over four decades and found no association between changes in occupational PA and future body mass index (BMI) and weight changes after adjusting for previous PA levels. No effect modification was also found in the association between occupational PA and BMI …