The 26-year-old actor gave up alcohol after he finished filming 2011's 'Harry Potter and the Deathly Hallows Part 2' because his drinking was getting out of control and says working out helped him to stay sober.
He explained: "Like the cliché of anybody who is quitting something, I really got into exercise."
Daniel also admitted drinking to excess and having to be looked after by pals on more than one occasion.
He told The Telegraph: "I can't tell you what kind of drunk I am because I don't remember what kind of drunk I am. I think I'm probably great - while I'm conscious. But then I have to be looked after and ultimately I don't want to wake up to 20 text messages along the lines of, 'Where are you? Dude, are you OK?'
"I change when I'm drunk. I'm one of those people who changes. There is something in any person who drinks in a way that's clearly not good for them, something that is attracted to that chaos."
And while he still enjoys going to the pub with friends, Daniel - who had one relapse but has not had alcohol in three years - leaves if his friends are getting drunk.
He explained: "I go to the pub - for a bit but then I'm like, 'OK, if you're all staying and getting drunk then I'm going to go because I can't do that.'
"Now I feel a lot more settled mentally, and am more comfortable with what makes me happy. More comfortable with the fact that I am a person that loves just hanging out with my friends. Or watching quiz shows. I am comfortable with the things about myself that I used to think, man, am I really boring? Should I be going out and getting wasted all the time?"