Actor Lee Jang Woo is currently preparing for his new drama "Pretty Man" by going on a diet.

On November 18, the cast and crew of "Pretty Man" gathered together for a press conference at the Imperial Hotel in Gangnam, and the actor revealed his thoughts on trying out his co-star IU's apple and potato diet plan.

"During our first filming day, we had nothing to talk about so I asked IU about her diet plan since I read about it before," he shared. "I realized that it was harder to lose weight once you get older so I tried it, but it was so difficult that I complained a lot. On the third day, I felt like I was going to die.""

He continued, "IU's diet consists of one apple and one sweet potato for the day. However, I only lasted a short while, and on the third day, I ate so much that I gained back the weight that I loss during the diet."

Meanwhile, IU shared her close relationship with the actor. She admitted, "I have been comfortable around Jang Woo since the first day. Our characters Bo Tong and David are like soul mates, but he is also kind in real life so I talk to him a lot."

Jang Woo plays the role of Choi David, an easy-going and kind guy who falls in love with IU's character Kim Bo Tong.

"Pretty Man" airs on November 20 at 10PM KST.