Jessica Simpson has been "obsessed" with her weight her entire life.

The Fashion Star mentor - who lost 60 pounds on the diet program following the birth of her first daughter Maxwell seven months ago, before announcing she is pregnant with her second child - admits she was a yo-yo dieter all of her life.

In a newly released Weight Watchers 360 advertisement in which she teams up with the company's other spokesperson Jennifer Hudson, that will hit screens on Thursday, the 32-year-old star says, "I obsessed about my weight my whole life... I was always on some new life-stopping diet." The former size 0 star then claims Weight Watchers, "let's me be me," and says "I amazed myself."

Meanwhile, Dreamgirls star Jennifer admits that the program completely changed her life as well and helped her lose 80 pounds over the past two years. "I was overweight my whole life. I figured I was just born that way," the 31 year-old singer says.

The mum-of-one will continue to be the brand's main spokesperson as Jessica "will not be following the program" during her pregnancy. The "With You" singer - who was reportedly paid $4 million to become the brand's ambassador - is expected to resume following the program after the birth of her second child.