I think it mentions this in the BSD book – it is on the first page of the “get active” tab of this website, and I have read about it recently, although that could have been an article elsewhere.
There was something about standing when you take phone calls – and logically going to speak with someone in a nearby office rather than phoning, The flexibility for this will be limited by your job though – harder if you are a front of house receptionist!
I’m not sure it will impact on weight loss per se – but it will prevent you from getting stiff, being in a bad posture for too long at a stretch, and so on.