Today, more than 1.5 million French women swear by its dramatic - and long-lasting - slimming results.
Politicians, film stars and high-profile models, including Gisele Bundchen and Jennifer Lopez, live the Dukan life, all of them seduced by its promise of the ultimate dieters dream - permanent slenderness while eating what you like.
Now this great French dietary secret is coming to Britain, with the launch next month of an English version of the Dukan Diet.
Unlike so many other diet fads that have come and gone, this plan is designed to get inside the head of the inveterate dieter.
It acknowledges the innate pleasure to be had from eating and, incredibly, promises efficient weight loss while eating unlimited quantities of real food.
The Dukan Diet is, in fact, four very different eating programmes that each follow on from the other.
It starts with a dramatic and rapid weight loss, and leads on into a structured, but simple long-term, real-food regime that ensures you never regain the weight you've lost.
The crucial element that links the four stages is the days spent eating nothing but protein. It may sound similar to Atkins, but the Dukan Diet is very different.
Protein days are used for crucial strategic effect at each stage of the diet, and dieters are urged to stay clear of butter and oil that forms one of the mainstays of the Atkins regime.
Due to the high amounts of protein, dieters are advised to drink three litres of water a day
Dr Dukan says he stumbled on the idea of a low-fat, protein-only element to his diet when a friend begged him for some dietary advice, saying he'd do anything as long as he didn't have to give up meat.
'I told him to eat nothing but protein and drink only water for five days, and when he came back he asked if he could use my scales because his appeared to be broken, ' he says.
They were stunned to see that he had lost 10lb. The patient stuck to the plan and went on to lose another 6lb over the next five days.
Dr Dukan was so amazed with the results and the effect this had had on his friend's weight and health that he switched his medical specialism from neurology to nutrition and spent the next 35 years researching and perfecting the various elements of his diet.
'It has become clear to me over the years that calorie counting does not work - dieters' brains don't work like that, ' he says.
'Calorie counting sets quotas, doses and portions, but it forgets that the people having to follow it are flesh and blood, made up of emotions and instincts.
'Yes, the most motivated ones may manage to lose weight, but all or almost all of them will eventually put it back on.'
He purports to have huge respect for Atkins but, as a doctor, refuses to believe that unlimited fat in the diet can be healthy. He is circumspect about its long-term impact.
Protein-based: It may sound similar to Atkins, but the Dukan Diet is very different
' When you remove the taboo surrounding fat, you create impossible long-term problems for people when they try to eat normally again, ' he says.
Many diets will help you lose weight, but most, he says, leave you stranded and alone when the pounds inevitably start to re-appear.
'Doctors assume their work is done once you've slimmed down, but there is something uncomfortable and unethical about having to face patients again six months later when their weight has returned.
'I couldn't stand the idea of putting people on a diet for life. That would be impossible - there is far too much pleasure to be had in eating!'
Instead, Dr Dukan came up with an innovative phase of the diet that gradually reintroduces, in successive layers, the basic elements of healthy eating.
This is carefully designed to control a body that, stripped of its reserves through weight loss, would be bent on revenge.
If you follow the plan to the letter, and your new weight becomes established and stable, the Dukan Diet eases you back to a life of normal, unrestrained free eating, with one caveat - you must agree to one proteinonly day (Dukan suggests a Thursday) every week for the rest of your life.
This lies at the heart of the great French slenderness secret. The French eat and dr ink wi th gusto and abandon, enjoying every morsel of their food, but now many of them atone for their enjoyment with one small sacrifice: eating only protein on Thursdays.
'By sticking to protein one day a week, you can lose 1.5lb to 2lb instantly and, in so doing, correct any excess that may have occurred during the rest of the week, ' says Dr Dukan.
'The idea of protein Thursday has taken off in France to such an extent that if I find myself in a restaurant with my family on a Thursday, I very often hear other customers around me asking for their fish or meat to be served straight, without vegetables or salad.'
Only one woman in four is happy with her weight and one in five is on a diet
Having stormed France, the diet has taken off in other parts of the world, and now, for the first time, he outlines the principles of his innovative slimming plan for the English-speaking market.
The Dukan Diet starts with a short, sharp attack phase where you eat absolutely nothing but protein - just meat, fish, eggs and non-fat dairy products.
This is the kick-start that gives you the initial impetus, the dramatic weight loss, and sets the tone for the other diets in the Dukan plan.
Because it is extremely effective, this first stage of the diet produces obvious and immediate results - many people can expect to lose as much as 7lb in just five days.
You can dip your toe in the attack phase for as little as one day or stick with it for as many as ten days, but if your true weight is two or three stone away, then five days produces the best results.
If you have around a stone to lose, two or three days on attack works well; if you are looking to slim down only by 7lb, a single day in the attack phase (where you'd be expected to lose 2lb instantly) is often enough to get you started.
A short-term, protein-rich regime like this will purge the tissues of excess water, dull the appetite (if you eat only protein foods, your body produces ketonic cells that are powerful natural appetite suppressants) while maintaining muscle tone and skin glow.