Justin Bieber Strips for Fashion Week, Flashes Six Pack Abs: His Diet and Workout Secrets

Justin Bieber stripped down at the New York Fashion Week's Fashion Rocks event last week when he was being booed at by the audience. The boos immediately turned into screams of excitement.

Bieber showed off his six pack abs and took the crowd by shock. The otherwise young lanky boy has worked hard in the gym for a fitter and more macho look. He was at the event on stage with model Lara Stone to introduce singer Rita Ora. The crowd's booing provoked the young singer to strip down; he was standing on stage only with his Calvin Klein underwear.

"I don't feel comfortable unless I'm in my Calvins," he said. "Is that better? Is that cool?" Later he revealed on Instagram that he had not planned the whole thing and it was just spontaneous. He wrote, "Just stripped on national television. Hahahaha, it wasn't planned lmao."

Later, he tweeted,

Grandma always said kill 'em with kindness...and then strip on live national tv. Lol. https://t.co/bKbeDJVsqJ

— Justin Bieber (@justinbieber) September 10, 2014

He even added Vine clip in which a fan has zoomed in on his crotch.

Justin Bieber has been working all year to get in shape. His earlier trainer was Dolvett Quince,but in 2011 he joined The Biggest Loser and he stopped working with Bieber. Currently, the singer is working with trainer Patrick Nilsson.

His Instagram pictures show him working out in the gym, and the workouts have paid off. He previously weighed just 108 pounds. But on Twitter, he revealed that he has been working really hard past two years concentrating more on building his muscles. "I've been working out in the gym, getting bigger, trying to get sexy for the ladies," Bieber revealed.

In an interview with ABC News, Nilsson revealed Bieber's workout routine. He said that Bieber works out for 40 minutes each day and trains five days a week. The main aim is to build his shoulder and chest muscles.

Nilsson said that he wants Bieber to look like Marky Mark. He said that this is what he feels like the young singer needs to get to. He's definitely leaner and a lot stronger.

When it comes to his diet, Nilsson said that Bieber is his only client who is allowed to go to McDonalds as he has a tendency to skip meals and eat less to keep up with his busy schedule. The main aim is to have him consume enough calories. "It's more about making sure he eats," said Nilsson. "He also likes chicken breast, whitefish, salmon, turkey, steak, rice, mashed and regular potatoes and weird greens like cauliflower."