Kate Middleton’s controversial wedding diet

Is a 69-year-old doctor behind Kate Middleton’s recent dramatic weight loss? Pier Dukan, dubbed the Dr Atkins of France, is responsible for Europe’s most popular diet book. And it’s reportedly one that Kate Middleton and her mother Carole are following to drop pounds before the royal wedding.

The book, which was released in Australia last year, focuses on a protein-rich, low-fat approach to weight loss. Outlined in the book are the four phases of the Dukan diet: the first involves a strict menu of non-fatty protein (skinless turkey, chicken breast, low-fat beef, or fish), plus 1.5 tablespoons of oat bran daily and loads of water. In phase two, dieters are introduced to veggies. Phase three; they’re allowed two slices of bread, a serving of cheese and fruit and two servings of carbs a day, with a wine-and-dessert allowance two days a week. In the final phase of the diet, 'Dukamaniacs', as they're called, can eat anything they want provided they return to phase one’s protein, oat bran and water regimen one day a week.

GALLERY: Kate Middleton - queen of hats

According to the Daily Mail, Carole Middleton lost four pounds in four days following the diet. Her daughter and soon to be Princess Kate, is rumoured to have hopped on the Dukan bandwagon, as well, amidst public concerns over her shrinking frame. Kate's given no confirmation of her diet plans to the press. “It’s a hugely private matter,” a royal press aide told the Associated Press.

The Dukan diet is the kind of plan that doesn't just cater to royalty. Supermodel Giselle Bunchen and singer Jennifer Lopez swear by the diet to keep off those unwanted kilos. A huge hit with carnivores, as well as those who loathe the gym, the diet's low-impact cardio component only requires 20 minutes of walking. But health experts warn of nutritional hazard. Dietians Association of Australia spokesperson Tara Diversi said that the strict regime meant that people missed out on too many essential nutrients, “sure I think people can lose weight from this…but I don’t think there are any health benefits to it,”

Kellie Hogan from Nutrition Australia said women were too often caught up in this quick-fix approach which was the worst way to approach long term weight loss. “Unfortunately with weight loss, to do it in a way that has longevity is a slow process,” she said.

The French agency for food, environmental and occupational health safety (ANSES) warns that the diet contains too much salt and not enough vitamin C and fiber, an imbalance that could take a serious physical toll on the body. ''The Dukan diet is associated with an increased risk of cancer and heart disease, even if this has not yet been proved in tests,” says ANSES chief researcher Dr. Jean-Michel Lecerf in Daily Mail. Lecerf also believes that after initial weight loss, dieters are likely to put the weight back on.

Dukan has dismissed those allegations as unscientific and counters that his diet can prevent obesity. But for already skinny women, like Kate and Carole Middleton, the diet may be more cosmetic than health-based.

Recent photos show Kate looking gaunt in the face with bony legs

Kate last October looking healthy and toned

A fuller Kate a few years ago