Scary skinny Christian Bale wasting away – all for the sake of art!

 "You gotta eat, man. You’re messing with your health!" Mark Wahlberg made that desperate plea to co-star Christian Bale when Bale continued to starve himself after dropping more than 40 pounds for their film The Fighter, sources say.

"Christian IS a method actor," a Hollywood insider told The ENQUIRER.

"If a role calls for him to look like a drug dealer, or he has to play someone who hasn’t slept in a year, he’ll go without food to look the part.

"But the danger comes after he takes off all that weight, and then eats everything in sight to put it back on for the next role. That kind of yo-yo dieting can be deadly. Mark and Christian are friends, and Mark is concerned about him."

Five years ago, Bale lost 63 pounds to play an emaciated insomniac in The Machinist A year later he bulked up to play the Caped Crusader in Batman Begins.

Now the talented and intense 35-year-old star looks scarily skeletal for his role as a boxer-turned-trainer who’s nearly KO’d by drugs and crime in The Fighter.

"It’s crazy. Christian has been living on fruit and water. He’s emaciated," the source said.

"Besides eating practically nothing, he exercises a lot to keep the weight off."

When The Fighter wraps, Bale will start bulking up AGAIN to go batty in next Bat- sequel, said the source.

And Wahlberg – a health fanatic who worked himself into great shape has begged Bale to stop dieting, said the source.

"Mark feels Christian is taking the whole ‘in character’ thing too far. He’s afraid Christian is getting Karen Carpenter-thin, and he’s worried about his heart," the source divulged.

"He wants Christian to realize that acting is a job, and it’s not worth risking your health."