Fast-forward to current day, where the 20-year-old feels she's in a "beautiful, healthy and safe place," she declared in a YouTube video.
"I just want to kind of open up the conversation, because I think it's a really important topic and one that not a lot of people discuss," she explained. "It's kind of taboo and brushed under the rug. I think it's really important to kind of bring light to it."
Lukasiak added that she's publicizing her struggles so that people who are suffering know they're not alone.
"That was one of my biggest things when I was going through my experience," the JustFab ambassador revealed. "I felt so alone and alienated and like I was the only one going through this."
The star then answered a few questions from fans, first detailing how her disorder started.
While some assumed that being on Dance Moms prompted things, she said that she was actually happy during the show, as she was burning calories everyday. It wasn't until after the series wrapped up that things went south.
Since the Girl on Pointe author was no longer exercising everyday, she began gaining some weight, as she never changed her diet. And once she did start to notice her body filling out, body dysmorphia started to "become an issue."
"I was unfamiliar with what I saw in the mirror and it was unacceptable in my eyes because of what society had taught me about what looked beautiful," she explained, noting she was around 15 at the time.
In the beginning, she struggled with just bulimia, but when she moved to Los Angeles at 18, the "anorexia started a little bit."
It wasn't until recently that she decided to reach out to a professional for help, sharing, "Last year is when I started to heal and go to therapy and tried to stop those behaviors."
To watch Lukasiak's full video, click here.