Demi's rant as mag claims Kate is expecting an 'heir' to throne

Laura Butler

DEMI Lovato has jumped to the defence of Kate Middleton after a US mag claimed the Duchess of Cambridge was pregnant because her belt was loosened.

The 20-year-old actress -- who is rumoured to have a close relationship with One Direction's Niall Horan (19) -- has been particularly riled by a report in American Star magazine suggesting that the Duchess of Cambridge is expecting her first child.

Demi, who was admitted to rehab in 2010 to battle an eating disorder, took to Twitter to slam the Star after it claimed Kate Middleton was pregnant because she looked to have loosened her belt at a recent event.

She wrote: 'So apparently Kate Middleton (William?) is pregnant because of THIS picture... Are you KIDDING ME?!!'

'And people wonder why girls/guys have body image issues. Whether she is or not, she still has a beautiful body. Shame on you Star magazine.'

Showing a close-up of Kate's waistline in a pink lace dress, the article suggests the royal must be pregnant because she had the sash of the gown extended by a couple of inches.

This isn't the first time it has been claimed the future queen is expecting an heir to the throne.

In November 2011, InTouch magazine reported Kate was six weeks' pregnant -- meaning she would have given birth in June.

However, royal watchers may not have to wait too long until the official news comes that Prince William and his wife, who are both 30, are expecting their first child.

The couple are currently on an official trip to Singapore, and during an official visit yesterday William made it clear that he wanted kids.

When asked by a little boy how big a family he would like, he answered without hesitation: "Two."

Kate has become one of the most popular members of the Royal Family despite only marrying William less than 18 months ago.