Justin Bieber reacts badly to vegan diet, girlfriend Selena Gomez brands him a ‘jerk’

Most girlfriends like to encourage their boyfriend to eat healthily but in Selena Gomez's case, it seems she wants nothing more than for Justin Bieber to eat a greasy Big Mac.

Selena hasn't taken kindly to Justin's new attitude since becoming vegan. [Copyright Wenn]

The power pop couple's relationship reportedly became heated following Justin's decision to go vegan.

It seems that Justin Bieber sans meat isn't a great combination.

[Related Story: Justin Bieber opens up about 'hot girlfriend' Selena Gomez]

Star magazine reports that girlfriend Selena Gomez was less than impressed with the way the diet had effected the Biebs, allegedly saying it had 'turned him into a jerk'.

An insider told Star magazine: "She [Selena] had encouraged the health kick but told him to drop it. She said that being vegan turned Justin into a jerk."

Usher encouraged Bieber to go vegan. [Copyright Wenn]

The source continued: "His mood took a major nose dive — he was such a brat."

"Soon everyone was begging him to just eat a steak!"

And sounds like Justin was acting like a total 'Baby' (see what we did there)  after taking a disliking to tofu steak when out for dinner.

"Justin ordered a tofu steak and tempeh tacos from Real Food Daily in L.A. and was really grossed out. He made a big show of spitting out the food and making gagging noises."

Justin decided to cut meat out of his life after he was encouraged by mentor Usher to try out the vegan lifestyle.

Little did Usher know, he'd be creating a monster.