Jessica Simpson has admitted she wasn't ''perfect'' during her recent weight-loss regime.

The 'Fashion Star' mentor - who is currently expecting her second child with fiance Eric Johnson after giving birth to their first daughter Maxwell in May - has revealed her slimmer figure after shedding more than 50 pounds for her latest Weight Watchers ads and insists that her diet wasn't particularly strict.

In the ad, which was reportedly filmed before she got pregnant again, the former size 0 star, who gained 70 pounds during her first pregnancy, said: ''I didn't need to be perfect to get here - to lose over 50lbs on Weight Watchers. It lets me be me, and I'm only human. I love food, I love life. I had no idea I could be so in control and so free at the same time.''

Jessica's new Weight Watchers ad is due to hit screens on Christmas Day (25.12.12) despite previous reports suggesting that her deal with the company was on shaky ground because executives were angry with her for getting pregnant so soon again after they gave her $4 million to be the face of the company.

According to an insider, the company didn't think they could continue to run any more ad campaigns featuring Jessica because she is pregnant.

The source said: ''They don't think it can run. No one wants to hear about a pregnant woman dieting.''

Jessica is yet to officially confirm she is pregnant but is said to be thrilled to be expecting her second child and was recently spotted indulging on grilled cheese sandwiches and onion rings.