Chris Daughtry Goes Shirtless After Buffing Up On New Diet

Chris Daughtry, rock star and contestant on American Idol’s season 5, revealed his new ripped body in shirtless twitpics.

Daughtry posted before and after pictures of himself on Twitter – one from 2010 and one from 2013. Slightly overweight in 2010, the rock singer displayed bulging biceps and washboard abs in the more recent picture.

Daughtry was inspired to start getting healthy after seeing the effects of living on tour. "When I've gone on tour in the past, everything has gone out the window," he told PEOPLE in September. "Late-night eating, junk food, pizza, donuts, beer. I gained 25 lbs. and I didn't realize it until I saw photos of myself and I went, 'Oh my gosh, I can't even see my jawline.

Who’s to thank for Daughtry’s complete body makeover? He credits 90 Day Challenge trainer Jen Herdenshott. “Big Thanks to @jenhendershott for being an incredible leader and helping me achieve my fitness goal. You’re awesome :),” he tweeted brimming with gratitude.