Objectives: To examine possible associations between driving to work, physical activity and overweight and obesity.
Design: Secondary analysis of cross-sectional data from a representative sample of the 2003 New South Wales Adult Health Survey, Australia.
Subjects: A total of 6810 respondents aged 16 years or over.
Measurements: Self-reported height and weight, modes of transport to work, level of physical activity, fruit and vegetable intake and social-economic status.
Results: Almost half of the respondents (49%) were overweight. The main mode of transport to work was driving a car (69%), 15% used public transport, 7% walked, 2% cycled and 6% worked at home. People who drove to work were less likely to achieve recommended levels of physical activity compared to non-car users (56.3 vs 44.3%, chi2 = 82.5, P<0.0001). Driving to work was associated with being overweight or obese (adjusted odds ratio = 1.13 (95% CI 1.01-1.27), P = 0.047). Inadequate level of physical activity was independently associated with overweight or obesity. Socially and economically disadvantaged people were also more likely to be overweight and obese. In addition, being female or never married or having higher level of education was associated with a significantly reduced odds ratio of being overweight or obese, as was speaking a language other than English at home. No association was found between weight status and recommended vegetable or fruit intake.
Conclusions: Driving to work is the dominant mode of commuting in a modern society and its impact on health requires scrutiny. The association found in this study between driving to work and overweight and obesity warrants further investigation to establish whether this relationship is causal. If proved as such, then promoting active transport modes such as walking, cycling and public transport should form a key component of global obesity prevention efforts.