Harry Styles has confessed he didn't know that former bandmate Zayn Malik suffered from an eating disorder while in One Direction.

Zayn's admission came during a candid interview in March where he spoke about his battle both with food and with anxiety.

His first mention of mental health struggles however came after he pulled out of Capital FM's Summertime Ball last year, later revealing his absence was due to anxiety.

Explaining he had experienced similar issues when he was a part of the chart-topping boyband, he revealed that his not eating was sparked by a feeling of being "in control," of his life; something he didn't feel in 1D.

Zayn told The Sunday Times Style magazine: "Every area of my life was so regimented and controlled, it was the one area where I could say, 'No, I'm not eating that.'"

When drawn on Zayn's experience, Harry, 23, confessed that he had not been aware of the Pillowtalk singer's demons.

Speaking to the same publication, Harry was asked if he wished he had known to which he replied: "I
mean yes, obviously."

He continued: "If anyone is ever going to go through anything, you always feel like you should know, so you could have done something. But it's not always how it goes, is it?"

One Direction's Harry Styles
Harry Styles has confessed his regret at not knowing and being able to help former One Direction bandmate Zayn Malik through his eating disorder ROBYN BECK/AFP/Getty Images

Zayn infamously left One Direction in 2015 and was the first of the five-piece to forge a solo career.

His first album Mind of Mine shot straight to the top spot in the UK charts and several other countries around the world including the United States, where he became the first British male solo artist to debut at number one.

Harry released his own self-title album last Friday (May 12). It included his number one debut single Sign of the Times which some publications declaring him the next David Bowie.

Zayn Malik Harry Styles One Direction
Zayn Malik (far left) pictured next to One Direction bandmates Harry Styles, Niall Horan and Liam Payne Reuters