I believe it, especially combined with regular strenuous exercise. This summer I was ACTIVE! Now starting back at school, just sitting at my desk, the pounds are not moving. I'm so tired at the end of the day I go home and crash.
I have a treadmill in front of the tv and I walk anywhere from 2.5 to 3.8 on it when watch a show. I also like to type at the computer at a rate of 2.0. I rack up some miles that way.
I too am not a fan of "just take the stairs" as a way to lose weight.
If only it were that easy. But in combination with everything else...heck yeah!