The actress, who will next appear in the Pretty Little Liars' spin-off The Perfectionists, which just received a pilot order, admitted on Tuesday's Dancing With the Stars episode that it hasn't always been easy being in the public eye, especially as her body went through major changes.
The 21-year-old actress, who is engaged to longtime love Hudson Scheaffer, revealed that she gained 70 pounds in the last two years, and that not everyone was nice about it.
"It was really, really hurtful the way people reacted [to my weight gain]," the Freeform star admitted on the dance show. "People were saying stuff like 'You're pregnant, you're fat.' They were angry. They were mad that I look like this."
She added that while fans were upset (ugh), she was actually dealing with a health issue.
"Very recently I was diagnosed with PCOS, Polycystic Ovary Syndrome, a hormone imbalance. Finally, I knew why this was happening to me."
This isn't the first time the PLL star has spoken out about body shamers. In 2016, the actress penned an Instagram post that clapped back at anyone who criticised her body.
"Truly loving yourself is one of the hardest things we as humans can do," Pieterse began in her open letter. "We live in a society that literally profits from our self doubt and insecurities. Women in particular are judged by their looks [whether] we are in the spotlight or not."
Pieterse added: "I decided at that point to love myself the way I am right now. That doesn't mean I don't want to improve myself, it means that I am making a point to love myself at every stage and chapter of my life."
With so much pressure to look a certain way, isn't it time we all do our part to spread a little kindness?