As part of his forthcoming memoir, Zayn Malik wrote transparently about several personal struggles he's faced over the length of his career thus far, touching on his ongoing battle with anxiety and his frustration with the musical aspect of being in a tightly controlled boyband. But he also revealed something new, admitting he struggled with an eating disorder during his last few months with One Direction.

“When I look back at images of myself from around November 2014, before the final tour, I can see how ill I was,” he wrote in his memoir, titled Zayn, according to The Sun. "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.”

Zayn said he didn’t eat for days at a time, citing his hectic work schedule as a contributing factor to his illness.

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

“I think it was about control," he continued. "I didn’t feel like I had control over anything else in my life, but food was something I could control, so I did."

Zayn said the lack of sustenance combined with the hectic life of being one-fifth of the biggest boyband on the planet negatively affected his health.

“I had lost so much weight I had become ill," the Mind of Mine singer wrote. "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.”

Zayn later addressed the passage in an interview with the Associated Press, though he downplayed his own claim that he was suffering from an eating disorder at the time.

"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, so it was a mixture of everything," he told the publication on Friday (October 28).

"I don't think I ever had an eating disorder,” he continued. "I was never diagnosed with one of them.”

But he notes he's developed healthier eating habits now that he’s out of the group: “I’m a bit older and a bit more wiser.”

The “Pillowtalk” singer also touched on his own crippling anxiety in Zayn, recalling the time he was forced to pull out of the Capital Summertime Ball earlier this year.

"I just couldn’t go through with it,” he wrote via TIME. "Mentally, the anxiety had won. Physically, I knew I couldn’t function. I would have to pull out.”

He continued, saying that while his team offered to put out a statement claiming he was sick, Zayn ultimately decided to be honest about his anxiety in hopes of helping others cope with their own mental health struggles.

"When I was in One Direction, my anxiety issues were huge but, within the safety net of the band, they were at least manageable," he wrote. "As a solo performer, I felt much more exposed, and the psychological stress of performing had just gotten to be too much for me to handle—at that moment, at least. Rather than hiding away, sugar-coating it, I knew I had to put it all out there."

Zayn says the reaction was overwhelmingly positive.

"But what I found in the wake of my cancellation at Wembley wasn’t hate but a massive amount of support from fans," he said. "Guys on Twitter were telling me how anxiety had affected their lives and saying that they were glad I had spoken up. It felt as though some good had come from the situation."

Zayn is set for a November 1 release.

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