The 26-year-old posted pictures of herself on Twitter showing off her body in a yellow lingerie while looking somber with her eyes closed.
"Bulimia and anorexia since I was 15. But today I join the Body Revolution. To Inspire Bravery and Breed some Compassion," Gaga wrote.
The singer also thanked her fans and her boyfriend Taylor Kinney for helping her battle the body-image issue.
"My boyfriend prefers me curvier, when I eat and am healthy and not so worried about my looks, I'm happy. Happier than I've ever been," she said.
She encouraged her fans to do the same by helping one another and embracing their bodies without fears of being judged.
"Now that the body revolution has begun, be brave and post a photo of you that celebrates your triumph over insecurities," she wrote.
Other celebrities having similar issue included Katie Couric, Demi Lovato and Salma Hayek.
