Jennifer Hudson is passing the torch to Jessica Simpson.

The slimmed-down singers have joined forces for a new Weight Watchers 360 commercial, which will air beginning Jan. 3.

"I was overweight my whole life," Hudson, 31, admitted in the ad. "I figured I was just born that way." (The Dreamgirls star has lost more than 80 pounds since teaming up with company in 2010.)

Wearing a figure-flattering black ensemble, Simpson added, "I obsessed about my weight my whole life. . . I was always on some new life-stopping diet." Participating in the Weight Watchers program, the pregnant star explained, "lets me be me."

For the next few months, Hudson will be the brand's main spokeswoman. Simpson, 32, "will not be following the program" during her second pregnancy, Weight Watchers recently announced. The "I Wanna Love You Forever" singer -- who was hired for $4 million -- is expected to resume Weight Watchers after the birth of her second child.

Us Weekly broke the news of the Fashion Star mentor's baby news in November. Simpson and her fiance, Eric Johnson, welcomed daughter Maxwell Drew in May.