Jessica Simpson has fluctuated between gaining and losing weight in recent years. After using Weight Watchers to lose 50 pounds, the fashion designer believes it helped her empire.

"I have been every size on the planet and I understand women," she told Forbes. "And I just know how to dress them."

Simpson publicly struggled with weight during her pregnancies with kids Maxwell and Ace. She remained positive and remembered that weight does not define you.

"I fluctuate, I'm a woman," Simpson said. "I feel like we all need to enjoy life. If I'm five pounds heavier or 50 pounds heavier or five pounds lighter, I don't think that should define who you are."

She then added, "I know there's all different kinds. There's life in the whole world beyond LA and New York. I understand Middle America and their mindset."

The Jessica Simpson Collection brings in $1 billion a year in revenue, consisting of 30+ product categories.

"I want to make every woman feel confident in what they're wearing," she said of her brand. "I do feel like we're very fashion-forward, but we also listen to the consumer."

"I think my brand has surpassed my name and my celebrity."

Simpson will marry fiancé Eric Johnson the weekend of July 4 in Santa Barbra. This is her second marriage; her first one to Nick Lachey was publicized on MTV's "Newlyweds: Nick and Jessica." Though they split in 2006, the songstress does not regret doing the show.

"I am blessed that I did have that show," she explained. "It allowed people to come into my life, and to know me as a person, and I owe a lot of my support - my fans came from that because people could relate to me."

She is also working on music again, so we have not seen the last of Simpson!