I started walking to work in June. About 3.5 miles from the closest bus stop to my job. In that time I went from 274lbs to 248lbs so 26lbs lost in 2 and a half months. I also started a new "diet" though not a very strict one. I basically eat whatever the hell I want until I'm full. Then don't eat a full meal the rest of the day. I snack on fruit or something light if I feel hungry. It seems to be working.
BTW Subway's meatball marinara subs are fantastic.