The dukan diet: demystified

Gisele Bündchen is rumored to have tried it, as is Jennifer Lopez. But it wasn't until Kate Middleton took her vows and became the Duchess of Cambridge last fall — and her physical transformation garnered almost as much attention as her Sarah Burton gown and maid of honor's derriere — that the Dukan diet began grabbing global headlines. The obvious weight loss, which Middleton has sustained post-wedding, wasn't attributed to a new fad, but an old standby: the French high-protein program created by Pierre Dukan in 1975.

Essentially, the Dukan diet is similar to the controversial Atkins plan but asks dieters to consume oat bran as its key ingredient. In the first phase, you're allowed unlimited amounts of non-fatty, protein-rich foods (meat, eggs, soy, nonfat dairy) plus a daily serving of oat bran. The second phase adds more daily oat bran and unlimited non-starchy vegetables every other day. The third dictates still more oat bran, and reincorporates daily veggies, whole grain bread, fruit, hard cheese and small amounts of rice or pasta (you're also allowed two "celebratory" eat-anything meals during this phase). In the final phase, any food is allowed along with three tablespoons of oat bran a day, regular exercise and one "phase one" day per week.

Can it possibly be good for you? According to experts, although quick and easy weight loss before a big event (televised across the world or otherwise) is what many people are hoping for with a fad diet, what the dieter does afterwards is what really matters. "Unless you are going to take a look at your habits and make a lifestyle change, it doesn’t matter if you stick to any diet for a few weeks," says NYC-based nutritionist Keri Glassman. "The Dukan diet is a quick fix that doesn’t teach life-long habits."

So what, if anything, is worth adopting from the Dukan diet? And what did Middleton hopefully leave behind?

Focusing on lean protein and unlimited vegetables is a great way of eating and a positive Dukan element, as is its commitment to exercise. But such sustainable aspects are overpowered by the plan's get-skinny-quick tricks. "There is definitely a gimmicky element to the Dukan diet, but maybe that's why it is so popular," says Jeffrey Morrison, MD, author of Cleanse Your Body, Clear Your Mindand a member of the Equinox Health Advisory Board.

People might be drawn to it because of the allowed "celebratory meal" and the "eat whatever you want" option in the final phase. But in fact, these are its most gimmicky elements, and quite often result in gaining weight back. "Once you kick a habit, it’s best to leave it buried. Just like a person wouldn’t have a cigarette every day after they’ve quit. I have seen too many people re-introduce a little sugar into their diet only to find they’ve opened Pandora’s box," explains Morrison.

While Glassman believes that people should be allowed "conscience indulgences" in small portions, she agrees this element is a part of the gimmick and promotes the wrong attitude about food. She also finds the daily oat bran requirement non-sustainable and unnecessary. "These elements are not teaching people eating skills, they are just being restrictive."

Whether it is the tricks for rapid weight loss or the proof of it in a celebrity, fad diets will always come and go. With each Atkins, South Beach or Dukan, the weight of its followers will yoyo in between weddings, indulgent holidays and summer trips to Mexico — unless the diet is used as a jumpstart into a healthier lifestyle, in which one makes conscious and realistic decisions about food.