I'm about to start something like this as I have the 'losing weight but losing it from the wrong bits' issue mentioned in another post.

I am physically active, I don't drive, I walk around 3 to 4 miles a day as part of my commute, I go up and down three or four flights of stairs quite a lot of times a day (I'm a teacher and timetabling systems seem to have a Saltationist bias as they have us jumping between lessons) and I work mostly standing up and moving around a large room. So I imagine a vaguely similar activity profile to the hunter gatherers mentioned - I'd love more detail on miles walked per day &c.