Dukan Diet: How to Lose Weight Like Carole Middleton

Shaping up for her daughter’s royal wedding, Kate Middleton‘s mom’s wedding motto seems simple: No carbs, no problem.

Carole Middleton says she’s been following the Dukan Diet, devised by Dr. Pierre Dukan, a French medical doctor who’s bringing his plan to the states. The U.S. Version of Dukan’s Web site will launch in January, and his book, The Dukan Diet, will be available in May.

Months away from the April affair, Dukan talked to PEOPLE about his diet regime, nutrition inspiration and how the key to dropping the pounds may be a staircase away.

What inspired your diet plan?
When I was a young doctor in 1975, one of my patients asked me to help him lose weight. He said a sentence that changed my life: ‘I’ll do everything you want except not eat meat.’ I said, ‘Okay, eat only lean meat, drink water and return to me in five days.’ He did – and he lost almost 12 pounds. That was the beginning.

What exactly is the Dukan diet?
It’s very simple – and it’s good for people who have tried to diet without success. It’s composed of four stages: two for losing weight and two for stabilizing weight. I use 100 foods: 72 are rich in protein but lean and 28 are vegetables.

How does the stabilization part work?
During the third phase, you add two slices of bread, one portion of fruit and cheese, along with two servings of carbohydrates. You also get two celebration meals a week. You can have anything you want – but only one portion of it.

What’s the final phase like?
[Phase four is] the key to success, and it’s not negotiable. You can eat what you want, but you have to follow these simple rules: Every seven days, you have to go back to phase one and eat from the 72 protein-rich foods. You must walk 20 minutes every day, you can’t take an elevator and you must eat three tablespoons of oat bran a day.

Why is your diet effective for frustrated dieters?
It’s low on frustration because you can eat as much as you want. Secondly, it’s very quick, especially in the beginning. You can lose a lot in the first six days. And the book has 1,200 recipes that come from the community of people who do my diet. That helps a lot.