Joe Jonas says Demi Lovato is the 'best version of herself' right now

Joe Jonas believes Demi Lovato has battled through her struggles to become the "best version" of herself.

The singer was previously troubled by a number of issues, including drug abuse, self-harm and an eating disorder.

Speaking to Billboard, Jonas - who worked with Lovato on the 2008 Disney film Camp Rock - said the singer is now flourishing.

He said: "She's the best version of herself I've ever known. She's healthy and that's obviously something a lot of the world knows now, but she's gotten over [the really hard part].

''I know a lot of friends who've gone through similar things and it's when you have to live with your new self for a few years - that comes with a lot of struggle. And being a pop star on top of that, that's a lot of pressure, but she's amazing at speaking truth to what she believes."

The US star added that he is envious of Lovato's ability to speak her mind in public.

Jonas said: "I wish I could have a bit more of that. Excuse my language, but she doesn't give a f**k. She goes out there and says, 'This is who I am.' Considering what we've all come from, it's not always easy. We feel like we have to be cautious."

Watch Joe Jonas in action below: