Lay summary
Kernel density estimation (KDE) is an emerging spatial analysis technique that takes into account both the proximity and density of features of the environment (e.g. parks, fast food outlets) in relation to each other. This developing field of research can provide valuable insights into the role of food and physical activity built environments in enabling or hindering children’s healthy lifestyle behaviours. The aim is to develop and test novel indices of the food and activity environments with a range of datasets that include children and youth of varying ages and life stages to develop age-specific measures of neighbourhood environments.