"When I started Weight Watchers, I didn't know what to expect at the meetings," the bubbly blonde says in the latest advert.
"It reminds me that we don't have to do this alone. It's so much better to have some back-up since we all face similar challenges. I can honestly say I've never been happier."
It's not just Jessica’s body confidence that's putting a smile on her face. She is blissfully happy with her fiancé Eric Johnson. "The new year will definitely bring wedding bells, which is exciting… I think it's about time," the Texas-born beauty recently told People.
"Knowing that I have the wedding coming up is an incentive to stay on Weight Watchers, count my points and stay in the gym. I mean, when you see my dress, you'll know."
On Monday, Jessica shared a black-and-white Instagram shot of her and Eric sharing a kiss. "Goodnight kiss. I love this man," she captioned the intimate photograph.
The singer also frequently shares pictures of her two beautiful children, daughter Maxwell Drew, 21 months, and eight-month-old son Ace Knute.
Last week she posted a snap of her and her little girl wearing matching sunglasses, and recently uploaded a photo of herself sat on the floor with her son. "American Idol captivated him," she wrote alongside the sweet picture.