Zayn Malik Reveals He Had a 'Quite Serious' Eating Disorder When He Was with One Direction

Zayn Malik is opening up about a “quite serious” eating disorder during his time in One Direction.

The singer explains that he only realized “how ill” he was after seeing photos of himself in 2014, in an excerpt from his new autobiography, Zayn.

“Something I’ve never talked about in public before, but which I have come to terms with since leaving the band, is that I was suffering from an eating disorder,” Malik, 23, writes. “It wasn’t as though I had any concerns about my weight or anything like that. I’d just go for days — sometimes two or three days straight — without eating anything at all.”

“It got quite serious, although at the time I didn’t recognize it for what it was.”

Malik says he didn’t restrict his diet intentionally.

“I think it was about control. I didn’t feel like I had control over anything else in my life, but food was something I could control, so I did,” he says. “I had lost so much weight I had become ill. The workload and the pace of life on the road put together with the pressures and strains of everything going on within the band had badly affected my eating habits.”

Malik, who quit One Direction in March 2015 and now has a solo career, downplayed his statements about his eating disorder in an interview with the Associated Press.

“It was just more down to losing track of, you know, actually eating, and being super busy and getting caught up with other things that 17- or 18-year-olds do, which normally entails them going out, drinking or partying,” he says, explaining that it was more a lack of time management.

“I was never diagnosed.”

WATCH: Zayn Malik Invites Fans to ‘Judge Me on My Own Terms’ in New Self-Titled Autobiography

Malik penned a letter for TIME Monday, where he detailed his current struggles with anxiety, which led him to cancel a solo concert in Dubai in September.

“Unfortunately, anxiety, which has haunted me throughout the last few months around live performances has got the better of me… with the magnitude of the event, I have suffered the worst anxiety of my career,” he wrote.

“It’s this thing that swells up and blocks out your rational thought processes. Even when you know you want to do something, know that it will be good for you, that you’ll enjoy it when you’re doing it, the anxiety is telling you a different story. It’s a constant battle within yourself.”

Zayn is out now.