He's also been spotted in Miami filming a new music video. Basically, after flying under the radar for a long time, he's back in the spotlight. And that means scrutiny.
Many fans are voicing their concerns on social media about Zayn's weight, thinking that he has become 'too skinny'.
Zayn has actually suffered from an eating disorder before, which he opened up about after he left One Direction.
Chatting to The Sunday Times Style magazine in March last year, he revealed that "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,'" he revealed.
"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 … 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 recognise it for what it was."
Fans have also come to his defence after seeing people scrutinise his weight.