Jessica Simpson's 100-Pound Weight Loss Is A Disappearing Act In Tight Black Dress

Gettyimages | Raymond Hall

Jessica Simpson looks unrecognizable these days. The "Dukes of Hazzard" actress and singer has lost a staggering 100 pounds since welcoming her third child – baby Birdie was born in March 2019.

Jessica has been fronting media outlets galore as her "Open Book" memoir details everything from her childhood sexual abuse to her resulting battle against alcohol and pills, but the 39-year-old is still wowing her fans with her slimmed-down figure.

In fact, it looks like Jessica's new silhouette has taken on a bit of disappearing act – a new photo of the blonde on Monday showed just how whittled-down she is.

Click here for the snap.

Jessica Simpson/Instagram

Jessica's Monday photo showed her ahead of her NYC appearance as she promotes her book. The blonde was standing in a hallway and looking business-ready in a chic look that was definitely showing off her weight loss.

Jessica had opted for an all-black outfit, flaunting her tiny waist in a tight and long-sleeved black dress. The clingy fabrics were showcasing just how slimmed-down the star is, with Jessica's weight loss also visible in her face. The actess wore dark shades with her long blonde hair down, also rocking a chic dark brown handbag and leather boots.

"#OpenBook Tour I’m coming for you! First stop - NYC ? #OpenBookLOOKS," Jessica captioned her photo.

Gettyimages | GP/Star Max

Jessica's fans may once have thrown out compliments purely based on the star's looks, but times have changed. Jessica opening up to Hoda Kotb about her childhood sexual abuse, aged 6-12, alongside her substance abuse battles has seen a fanbase respond with one thing – respect.

That said, the weight loss was dominating in this update.

"How did you lose weight so fast?" one fan asked.

"Post baby body goals!" another said.

"What did you do to lose the weight so fast?" saw yet another fan query just how Jessica did it.

Keep reading for the secret.

Gettyimages | BG017/Bauer-Griffin

Jessica's weight loss was self-announced on social media as the actress unveiled that she'd lost 100 pounds. The star's personal trainer Harley Pasternak has since dished to Hollywood Life on how it all went down – Jessica lost the weight over six months.

“She would eat one whole egg and three egg whites for breakfast, scrambled with a bowl of blackberries. For lunch she would have a salad with grilled chicken and grilled fish with salad and vegetables for dinner. As for snacks, she would have almonds and sometimes green beans with Parmesan cheese on top. She was very disciplined,” he said.

Jessica Simpson/Instagram

Harley further revealed that Jessica upped her exercise in an effort to shift the weight. The star was walking up to 10,000 steps a day. Jessica also followed a low-sugar diet.

“So you get lean in life and strong in the gym. So those are the principles in and on top of that, it’s this low sugar lifestyle is essential. And luckily Jessica’s predication is more to savory food and Tex Mex flavoring," Harley continued, letting fans know that Jessica is into her spicy foods.