This may be problematic for assessing the risk of obesity or for understanding how to design
environments to promote healthy behaviours, such as active travel which has been found to be associated with lower BMI (Flint et al.
2014). In terms of obesogenic environmental exposure, using modelled routes may underestimate exposure to unhealthy food
environments for some people, such as those with children, whereas it may overestimate exposure for others, such as those in better
health. This reflects the fact that different population groups will make varied choice sets when deciding which route to take, which may
introduce bias into studies if health-related behaviours, such as seeking food or physical activity opportunities, are associated with
disparities between modelled routes and those actually taken