[steeljack]

just a general observation from my own surroundings , the folks who live in the suburbs and are more dependant on a car being parked at the front door seem to be a bit bigger than the people I know who live 'downtown' and use public transport to get around . Best examples I can use for the US are NYC and San Francisco , both high density population/low car ownership cities (both cities also have the lowest number per capita of licensed drivers). The opposite arguement to this is that urban areas have more fast food places than the 'burbs' which should mean that city folks would be bigger .
Think it just boils down to folk not walking as much as they used to do , even if its just to the bus stop