The "In the Name of Love" singer shared her frustrations in a video posted to Instagram on Monday, January 21, in which she called out fashionistas who thought she was "too big".
The defiant pop star raged, "If a size six (or) eight is too big then I don't know what to tell you. Then I don't want to wear your f**king dresses. Because that's crazy. You're saying that all the women in the world that are size eight and up are not beautiful and they cannot wear your dresses."
Bebe has since been inundated with offers from designers like Christian Siriano to dress her for the Grammys next month (February 2019) - and support from stars like Tyra Banks and Mayim Bialik, and now Demi has chimed in.
"F**king preach!" the "Cool for the Summer" singer wrote on Wednesday. "Love this and you for speaking your mind and using your voice!!!"
I love @BebeRexha she such a strong beautiful woman 💗 preach 💗 say it louder for everyone to here beautiful 🥰 we by your side and @ddlovato is so sweet she always supportive To other celebs 💗 pic.twitter.com/JerWmjdA2o— kaylamedlin (@kaylareneemedd) January 23, 2019
Lovato, who has battled eating disorders and self-hate problems in the past, has often spoken out about body image issues.
Her support for Rexha is one of Lovato's first social media posts since she checked out of rehab last summer (18). The singer sought treatment after she was hospitalised following an apparent drug overdose.
Meanwhile, reports suggest Rexha is leaning towards Siriano and Michael Costello for her Grammys gown after they reached out to offer to dress her for music's big night.
"We have dressed @beberexha a few times and would be happy to do it again for her," Christian wrote on social media, while Costello told TMZ, "I've been friends with Bebe for a really long time (and), I'm sad that she didn't call me first because I would have said yes... I’m going to get bashed for saying this but, I'm with her. F**k those other designers who only want to dress the size two girls."
August Getty, Tanya Taylor and Elizabeth Kennedy have also reached out to Bebe and offered to style her.