Kelly ClarksonKelly ClarksonAmerican Idol winner Kelly Clarkson has denied rumours that she's under pressure to lose weight.

It had been reported that the singer would miss out on a big advertising deal if she didn't shed the pounds.

But Kelly insists that whole thing is just one big joke.

According to her publicist, she's already completed her first photo shoot for drink company Vitaminwater so "nothing could be further from the truth".

Previously, Kelly has explained that she's more interested in eating healthily than being skinny.

She told Entertainment Tonight: "Why I love the Vitaminwater campaign is a lot of kids just down soda and it's not good. Obviously, I have a lot of young fans, so that's why we teamed up.

"I just realized that I have a platform. If you have a voice, you might as well make it a positive one."