Our environment – the space in which we live, work and play – plays a huge role in how we behave. Probably a lot more than we realise.

This has been shown in research about eating and physical activity. People walk and cycle more when there are good paths and bike lanes, for example. And there's a whole huge area of industry devoted to designing supermarkets to make us move through stores and buy in certain ways.

A new study has shown the power of this idea in helping people make healthier food choices. And it's reinforced what we