"It was really just extreme how I was being talked to and talked about," she told The Guardian in an interview.
"I think I just got really turned off by it."
Silverstone said she was criticised a lot for her weight when she was promoting the film with George Clooney as the Caped Crusader and Chris O'Donnell as the Boy Wonder.
"They would make fun of my body when I was younger.
"It was hurtful but I knew they were wrong. I wasn't confused. I knew that it was not right to make fun of someone's body shape, that doesn't seem like the right thing to be doing to a human."
"[It] definitely wasn't my favourite filmmaking experience.
"There were working circumstances that were less than favourable in terms of how things went down," she said.
"And no, I didn't say 'f**k you' and come out like a warrior but I would just walk away and go, 'Okay I know what that is and I'm done, I'm not going near that again'."
The actress admitted she "stopped loving acting" for a long time because of the negativity and turned her attention to becoming a champion for animal rights instead.
"My body was just like, 'This is what I'm meant to do'," she said.
"I love it so much, I need to find a way to do both, to be able to be an actress and be an activist at the same time so that's what I did."
Silverstone may have taken a step back from acting, but is still set to star in the upcoming Netflix adaptation of the Ann M Martin book series The Baby-Sitters Club.
