Vince Vaughn found the perfect diet to bulk up for his character in new movie THE BREAK-UP - he quit smoking. The SWINGERS star was called on to play a portly slob of a boyfriend in the romantic comedy, opposite real-life girlfriend Jennifer Aniston, and admits he didn't have to try too hard to gain the extra weight and then lose it. He says, "I had quit smoking a pack of cigarettes a day just in time to put on 25 pounds. Then, when we finished shooting, I said to myself, 'Well, I can have just one cigarette. It's been eight months. What's the big deal?' "Of course smoking curbs your appetite, so I lost the weight. I plan on quitting but I'm not quitting right this second."