Kevin Jonas has revealed his pregnant wife Danielle is craving grapes.

The Jonas Brothers singer has admitted his spouse of three-and-a-half years had been struggling to cope with some of her pregnancy side-effects after suffering bad morning sickness but now she's feeling better she's developed a hunger for the sweet fruit.

Speaking to People magazine, he said: ''The nausea has finally subsided. Danielle's feeling much better now in the last couple of days, which is a really big step. She's not sick anymore.''

''She can't stop eating them [grapes] - like non-stop,''

Kevin, 25, has been swatting up on how to become a doting father after announcing earlier this month that he was expecting his first child with Danielle.

He explained: ''I've got a bunch of books. ''[I'm also reading something about] how to sleep a night after four weeks.''

The star previously claimed he would prefer to have a daughter because there is already too much testosterone in his family.

He said previously: ''I would love to see a girl in the midst of all these boys all over the place. But then again, at the end of the day, if it's a boy - oh man, we're starting trouble.''