True... I couldn't know it in a scientific sense. But I went from a commute from garage to parking lot and a weekly outing to the bowling alley, to all that walking, standing, and stair climbing. It was a couple of hours daily by the time you added it all up. That's a good, I dunno, 400 calories daily of additional burn? So I had to be eating more as well, or I would have dropped a lot more weight than 15 pounds in 2 years.
400 calories is a half hour running, for comparison. I think you'd be closer to 100-150 calories, as standing does not consume much (not saying it is not unpleasant, but as energy consumption go, it's pretty negligible) and walking consume way less than running.
It's always good exercise, and probably helped to look slimmer. However, as other mentioned, losing weight via exercise is not that easy, and a good diet is way more important