Cameron has joined the 'skinny' debate (aka size 0 debate) expressing her concerns about the influence of ultra-slim celebrities.

Her comments echo those of Billie Piper and Kate Winslet, who have both recently voiced criticism of the phenomenon.

Speaking on the issue, Cameron, 34, said: "I think it's terrifying, it's tragic and sad. It's a sickness, something that's going on in someone's head where their perspective is off."

She added: "We get ideals from images that we see and there certainly should be more responsibility put on those people who are putting those images out into the world. Let's be a little bit more responsible to what's realistic."

Last week, former Doctor Who star Piper said Victoria Beckham should not be a teenage role model - because of her tiny frame.

The star, who suffered from anorexia, said she worried that younger people were looking up to skinny stars.

Former singer Piper, 24, said: "I think the whole size zero debate is disgusting."

She added: "Some models you see are tiny because that's the way they were born, but then they'll get the attention and that will start feeding a fire."

Winslet also joined the debate, describing the trend as "unbelievably disturbing".

Nicole Richie and Kate Bosworth are among the celebrities whose shrinking figures have been the subject of debate.

The controversy over underweight models has been raging since the death last month of Ana Carolina Reston, 21, a Brazilian model who suffered from anorexia.

In August, a Uruguayan model Luisel Ramos, 22, died of heart failure after not eating for several days.