United Kingdom, Aug. 6 -- Zac Brown has "retired from drinking" as part of his healthy new lifestyle.

The 47-year-old country star has undergone a huge change in recent months after deciding to overhaul his diet and exercise regime - cutting out booze along with sugar and dairy - and working out with a former NFL trainer.

Zac admits his gruelling new routine takes a lot of discipline, but he's fully committed. He told GQ magazine: "Nobody could have told me that I needed to stop drinking before I knew that it was time to do it.

"But there were times when I had hangovers and I'd look at myself in the mirror and go: 'One day, I'm not going to do this anymore.'

"You kind of feel like [alcohol] is this feel-good friend that's always aroun...