First, the news about Virgin execs being worried about Janet's weight is from PopDirt.com (a very, very reliable source)
Second, Janet does this almost every time before an album comes out. She has gained weight, but I believe it is exaggerated by her intentional wearing of baggy clothes. I remember before the "Damita Jo" album, fans were concerned about weight. Then, she came out with 6 pack abs and then the critics had to shut up - but then the Superbowl mess happened and...you know the story.
So, Janet has always struggled with her weight. It is no secret. I thank God she is not in a worst condition considering the backlash she received in 2004, whether warranted or unwarranted. It was hell! So, I believe 2006 will be a much better year for her.