Jessica Simpson has teamed up with fellow diet diva Jennifer Hudson to discuss their slimming success in a new advertisement for WeightWatchers.

In the commercial, which will debut in the U.S. on Thursday (03Jan13), the brand's spokeswomen strut down a street and recall past struggles to shift unwanted pounds.

Hudson says, "I was overweight my whole life. I just figured I was born that way," while Simpson adds, "I obsessed about my weight my whole life. I was always on some new life-stopping diet."

Simpson, who recently confirmed she is pregnant with her second child, then praises the WeightWatchers plan, insisting, "It lets me be me. I amazed myself."

Company bosses have confirmed Simpson will not follow the diet during her second pregnancy, but she will resume the program after giving birth.

The I Wanna Love You Forever hitmaker has lost more than 50 pounds (23 kilograms) on Weight Watchers, while Hudson shed 80 pounds (36 kilograms).