Kelly Clarkson Reveals How Much Weight She's Lost and How

Kelly Clarkson opened up about the secret behind her stunning weight loss in recent months.The [...]

Kelly Clarkson opened up about the secret behind her stunning weight loss in recent months.

The "Love So Soft" singer, who has kept details about her new slim figure under wraps, talked to Extra about her recent transformation, crediting a book she read that changed her life.

"I literally read this book, and I did it for this autoimmune disease that I had and I had a thyroid issue, and now all my levels are back up," she revealed, according to Page Six. "I'm not on my medicine anymore because of this book, it's called The Plant Paradox (by Steven R. Grundy, MD). It's basically about how we cook our food, non-GMO, no pesticides, eating really organic..."

Clarkson reportedly did not go in-depth about her auto-immune disease or thyroid issues.

"I'm not working out! I think people think I'm working out and I'm like, 'Don't think I'm going to come play some sport!'"

She added, "Literally, I haven't worked out at all!"

Clarkson had been playing coy with her weight loss recently, crediting her glam squad with transforming her.

"I have to shout out my whole glam squad," Clarkson joked of her svelte appearance at The Voice finale in May. "I literally hired Harry Potter and Spanx; it's all like a sausage."

The American Idol winner has delivered stunning looks during her last few award show appearances, wearing gorgeous designs by fashion icon Christian Siriano. She recently also hosted the 2018 Billboard Music Awards on their first year being aired on NBC.

Clarkson recently scored her first victory on The Voice during her first season as a coach, with 15-year-old Brynn Cartel taking the prize.

The singer congratulated Cartelli with a post on social media following the show, sharing a photo of the two posing together on stage.

Clarkson also wowed with her outfit at the CMT Music Awards in Nashville, Tennessee, where she performed a cover of the classic rock song "American Woman." Her version of the song is the theme to Paramount Network's series of the same name, which premiered Thursday, June 7.

The show is inspired by the upbringing of The Real Housewives of Beverly Hills star Kyle Richards and follows Bonnie (Alicia Silverstone), an unconventional mother struggling to raise her two daughters after leaving her husband with the help of her two best friends, Kathleen (Mena Suvari) and Diana (Jennifer Bartels) in 1970s Los Angeles.

American Woman airs Thursdays at 10 p.m. ET on Paramount Network.