Junk food advertising

Does advertising junk food make children fat? Yes say doctors - so ban it before 9pm. No say advertisers - no evidence. They accuse the medics of "grandstanding". So who's right? New Labour cabinet minister James Purnell is one of the new DG's first appointments and will become the new director of strategy and digital. How's his appointment been received and what will he bring to the Corporation. And what's going on behind the scenes as the BBC prepares to publish the transcripts of the Pollard Review. Presented by Steve Hewlett. Producer Beverley Purcell.