The 30-year-old pop star talks about her struggles in "Miss Americana," a documentary that will be released on Netflix on Jan. 31 after premiering at the Sundance Film Festival on Thursday night.
"It's not good for me to see pictures of myself every day," she says in a voice-over in the film. "It’s only happened a few times, and I’m not in any way proud of it. A picture of me where I feel like I looked like my tummy was too big, or ... someone said that I looked pregnant ... and that’ll just trigger me to just starve a little bit — just stop eating."
Swift expanded on those comments in an interview with Variety in which she spoke about why she decided to address her eating disorder in the film.
"I didn’t know if I was going to feel comfortable with talking about body image and talking about the stuff I’ve gone through in terms of how unhealthy that’s been for me — my relationship with food and all that over the years,” she said. "But the way that (director) Lana (Wilson) tells the story, it really makes sense.
"I’m not as articulate as I should be about this topic because there are so many people who could talk about it in a better way. But all I know is my own experience. And my relationship with food was exactly the same psychology that I applied to everything else in my life: If I was given a pat on the head, I registered that as good. If I was given a punishment, I registered that as bad."
Swift began believing that starving herself was normal behavior.
"I thought that I was supposed to feel like I was going to pass out at the end of a show, or in the middle of it," she says in the documentary. “Now I realize, no, if you eat food, have energy, get stronger, you can do all these shows and not feel (exhausted)."
Being featured on the cover of tabloid magazines that dissected her appearance when she was a teen also had a damaging effect.
"I remember how, when I was 18, that was the first time I was on the cover of a magazine, and the headline was like ‘Pregnant at 18?’'' she told Variety. "And it was because I had worn something that made my lower stomach look not flat. So, I just registered that as a punishment."
"And then I’d walk into a photoshoot and be in the dressing room and somebody who worked at a magazine would say, ‘Oh, wow, this is so amazing that you can fit into the sample sizes. Usually, we have to make alterations to the dresses, but we can take them right off the runway and put them on you!’ And I looked at that as a pat on the head. You register that enough times, and you just start to accommodate everything towards praise and punishment, including your own body."
Swift struggled with whether she wanted to open up about the topic at all.
"I think I’ve never really wanted to talk about that before, and I’m pretty uncomfortable talking about it now,” she told Variety. “But in the context of every other thing that I was doing or not doing in my life, I think it makes sense."
Wilson applauded Swift's honesty given how many girls and women see her as a role model.
"I think it will have a huge impact,'' she told Variety.
Swift has also endured a difficult time in her family's life in the last five years, as her mother, Andrea Swift, 62, was first treated for breast cancer in 2015 and then had it return last year. Swift also revealed recently that doctors discovered that Andrea has a brain tumor, which they found while she was undergoing chemotherapy.
The singer also has had an ongoing public spat with Scooter Braun, the music executive who bought the rights to the master recordings of her first six albums from her old record label. She wrote on Twitter in November that Braun was preventing her from using performance footage in the Netflix documentary and then delivered a scathing speech against Braun at Billboard's Women in Music event last month.