Is Kate Middleton getting too thin? Experts dismiss idea that Kate will struggle like Princess Diana By Lindsay Goldwert

The British press dubbed Kate Middleton "Waity Katy" after her courtship with Prince William stretched for years without an engagement – but lately the tabloids are more focused on Katy's weight.

Middleton has always had a lithe, athletic build, but the trim princess-to-be has looked even more slender lately – prompting media cries that she's lost too much weight for her royal wedding and speculation that she may fall prey to the same web of pressures and pain that befell the late Princess Diana.

The prince's longtime love has been spotted working out at Di's old gym and she's rumored to be using a risky no-carb diet to drop pounds – arousing fears she may fall into the same obsessive quest for thinness and perfection that caused Diana so much misery.

But those who know the royal family well call the reports rubbish and say Middleton's emotional state couldn't be more different from the late Diana.

"The British press has been relentless in its attempt to portray Kate Middleton as a fragile young woman who is already falling prey to an eating disorder. It's absurd," said Christopher Andersen, author of "William and Kate: A Love Story" and the bestselling "The Day Diana Died."

The Princess brides: Lady Diana Spencer and Prince Charles in 1981 and Kate Middleton and Prince William in 2010. (Getty)

"Kate looks no thinner to me at all. She's always been a health and exercise fanatic, but not in an unhealthy way," he said.

According to royal lore, Diana became bulimic after Prince Charles hurt her feelings by calling her "chubby."

"Kate is not chubby at all, but if she was, William would never hurt her feelings in that manner," said Andersen. "Charles could be thoughtless, even cruel, in a way Williams never could."

Another difference is the marriages themselves.

There is no "other woman" lurking in the wings to mar Kate and William's special day. One of the reasons Diana became so thin and insecure at the time of her wedding was because she knew her husband-to-be was in love with his now-wife Camilla Parker Bowles.

"Diana was l9 when she married a man she already knew was in love with someone else," Andersen said. "She was driven over the edge by a royal family that treated her pretty shabbily."

Kate Middleton is 10 years older than Diana was at the time of her engagement and in a much better place, emotionally, because she's marrying a guy who seems completely devoted to herm said Andersen.

Another reason why Prince Charles and Princess Diana's marriage bombed was there considerable age gap, said Claudia Joseph, the author of "Kate: The Making of a Princess."

William's parents were 12 years apart in age while the prince and Kate are the same age.

"I think she already has a distinct advantage over Diana. She is older and wiser and will conduct her role in a more dignified and conscientious manner," Joseph said. "Kate has been dating William for nearly eight years and has had ample opportunity to learn from him how to cope with the role."

Joseph also shrugged off rumors that Kate is heading down a path to weight obsession and eating disorders.

"Certainly Kate has lost weight since she became engaged, but many brides drop pounds in the runup to their wedding," she said. "It does not mean she has a problem."