When Will Jessica Simpson Reveal Her New Post-Pregnancy Body After Being On Weight Watchers?

The "Irresitable" singer shocked fans with her massive weight gain during pregnancy-admitting to indulging in junk foods like butter Pop Tarts and mac and cheese.

However, four months after giving birth to Maxwell Drew the star has lost an astonishing 40 pounds, according to Star Pulse.

Need a specific day for Simpson's big reveal? The celebrity is set to show off her slimmer figure on news anchor Katie Couric's new show September 10 to millions of fans, the site said.

Simpson told Life & Style magazine that she attributed her weight loss to breast-feeding, marathon gym sessions and a personalized, no-starve Weight Watchers plan.

A source tells the publication, "Jess has been doing a lot of work on herself and she'll gradually be showing her weightloss through Weight Watchers commercials over the next few months."

According to posts from her Twitter feed, Simpson revealed that she filmed her first Weight Watchers reveal commercial on August 16.

"That's a wrap! Just finished shooting my first @WeightWatchers commercial! Stay tuned..." she tweeted.

But she admitted to USA Today that she's having a hard time getting rid of some of those extra, pesky pounds:

 "My body is not bouncing back like a supermodel. I'm just your everyday woman who is trying to feel good and be healthy for her daughter, her fiance and herself."

She definitely seems to be trying though after recently posting that she found a new show to workout to on Twitter.

"24 is my new treadmill show!! How have I not watched this show before now?!?! Jack Bauer is my hero!"

Do you think Jessica Simpson will be able to get her old body back?