In a new interview with Complex magazine, the British singer opened up about the band's strict rules to maintain their "young teen boy look."
"[It was] mainly my beard, honestly. I wasn't allowed to keep it," he said. "Eventually, when I got older, I rebelled against it, and decided to keep it anyway. That was just because I looked older than the rest of them. That's one of the things that is now quite cool. I get to keep my beard. I also wanted to dye my hair when I was in the band, but I wasn't allowed to."
Malik, 23, said that not being able to be "authentic" was part of the reason why he left the group last year.
"That was something that was always underlying, and [it] ended up as the main factor of me leaving in the end. It was about denying the authenticity of who I was, and what I enjoyed about music, and why I got into it," he said. "That was always there. It was one of the things that wasn't going to go away, so I had to go away.
"I believe that success follows authenticity," Malik continued. "People see through fake s---. They don't want to see that; they want a real person. That's why Kanye [West] is so successful. He's speaking the truth, regardless of whomever he offends, he isn't bothered. That's admirable."
Still, Malik said he's grateful for his experience with One Direction.
"No one can ever say I was ungrateful, even though it sort of comes across that way when I mention that I was frustrated with the band. That's not the case at all," Malik clarified. "That was just an experience that had to be dealt with at the time. With the music that I’m doing now, I get to express myself, and that creative tension is gone."
Malik's debut solo album, "Mind of Mine," will be released on Friday.