Chart-topping K-pop singer IU might appear to be the picture perfect of health.

Yet, in an open letter to fans, posted to her website on Friday, the pop star and actress described how a recent visit to her physician caused her to rethink her daily habits.

"I visited a doctor the other day and the results didn't come out so great," IU wrote.

"So I changed my exercise schedule and meal plan. I've been drinking two liters of water every day and going to bed and waking up early. I gained some fat recently. I want to get healthy again soon."

Yet, at the moment she was writing the message, she admitted her stomach was growling.

"It's a night where I'm craving rice cake," read the opening of IU's message. "I hope the morning comes soon so I can eat breakfast."

On Thursday, the singer, whose last album, "Modern Times," came out in October, announced that she will release an album of cover songs in May. It is reportedly the first time IU has recorded an entire album of other people's songs.

"I've been recording and I think it'll be a great album," she wrote. "I've chosen some unexpected songs too. It was hard to choose which songs to cover. But I'm really happy with how they came out."

IU also announced she will give an exclusive performance in a small theater at Seoul's Sogang University on May 22.

According to a representative from the singer's record label LOEN Tree, IU's intimate performance promises to be a special night.

"You'll be able to see IU singing in a concert hall, with a voice that reminds one of a fresh spring breeze and flowers blooming," the rep told eNEWS. "We're planning a new type of concert in a small place designed just to present good music."