How is it that the French can devour as much cheese, crème, chocolate, bread and wine as they like and still maintain their slim fashion-fit figures?
According to Dr Pierre Dukan, the French doctor behind the Dukan diet, the trick to it is having one day of protein-only foods a week, called "protein Thursdays".
For the past decade the Dukan diet has helped people in France manage their weight, the author says, and now it's caught on around the globe, with A-listers Jennifer Lopez and Giselle Bündchen jumping on board to maintain their slim figures.
It promises fast weight loss, around 6kg per month, and allows you to eat what you like except on a protein-fuelled day.
It's been hailed as the "new Atkins diet", but is it really a breakthrough in nutritional science, or just another fad?
The Dukan diet consists of four stages
- Attack. Eating protein exclusively for up to seven days, including meat, fish and non-fat dairy products.
- Cruise. You can have unlimited vegetables during this period, where you alternate protein-only days with vegetable and protein days.
- Consolidation. During the consolidation period, eat protein and vegetables every day. Add one piece of fruit, two slices of bread and a serving of cheese each day. Have a couple of starchy meals (such as pasta or risotto) each week as well as a couple of celebration meals where you eat what you like.
- Stabilisation. There's one rule during stabilisation: only eat protein on Thursdays. Everything else can be eaten without restriction.
The expert's verdict
"Yes you are going to lose weight because it's an enforced restriction to your calorie intake," nutritionist Joanna McMillan Price told ACA
She warns that the Dukan diet is not a sustainable, long-term solution and comes with nasty side-effects, such as constipation.
"It won't work because it's not teaching you, long-term, about good eating habits and about having a positive relationship with food," she said.
"We love the idea that we can lose weight really, really fast, and keep it off and still eat what I like, but that's really a dream and we're really buying into the dream that we can eat what we like and still have really good weight control."
The Dukan Diet by Dr Pierre Dukan, $29.99, is published by Hodder & Stoughton, and is available in bookstores.
Watch the video above for more information.