Justin Bieber is in trouble with girlfriend Selena Gomez for his eating habits - after she reportedly told him that his vegan diet 'turned him into a jerk'.

El Biebo was encouraged to try a vegan lifestyle by his mentor and fellow pop titan Usher, but it seems a meat-free diet didn't really agree with him.

“His mood took a major nose dive — he was such a brat," an insider told Star magazine. "Soon everyone was begging him to just eat a steak!

“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.”

And it all got too much for Selena apparently - the snitchy source added:“She had encouraged the health kick but told him to drop it. She said that being vegan turned Justin into a jerk.”

Hmm, could this lack of meaty goodness be to blame for the J-Dawg's run in with the paparazzi, and perhaps even his airport-based rant at his fans?

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Images: PA/WENN