The Dukan Diet and the Libel Case (Part 2 of Dukan Diet blog article)

I’m interested in high profile diets partly because, as a personal trainer in London, many of my new clients tell me they have been on some celebrity diet or followed some best-selling diet book without any long term success.

In part 1, I reviewed the Dukan Diet, a high protein, low fat, low carb diet which is followed by millions of people around the world. Dukan is different from the Atkins diet in that Dukan is low fat, and Atkins was emphatically high fat. But both share the advice to eat a lot of protein at every meal.

High profile nutritionists and diet book authors often threaten legal action if anyone dares to criticise their advice, but Dr Pierre Dukan went all the way, and sued one of his critics Dr Jean-Michel Cohen for $20,000 damages for libel in the French courts. In July 2011 the French court ruled against Dr Dukan, dismissed the libel action, and ordered Dr Dukan to pay 3,000 euros to Dr Cohen for ‘abusive procedure’.

What was Dr Cohen’s alleged libel? He said that the Dukan Diet could lead to “serious health problems in some patients”, pointing to the risks of excessive protein consumption: dehydration, kidney stones, gallstones, bone-thinning, cardiac disease, breast cancer. Dr Cohen, himself a high-profile nutritionist (and TV presenter), called the Dukan Diet potentially dangerous.

Dr Cohen’s lawyer, Richard Malka said after the trial: “it is not because you’re a good businessman, communicator, on the cover of magazines, that you can escape a legitimate science-based critique. What is essential is patient safety, not the touchiness of doctors.”

Dr Cohen was not the only one to criticise the Dukan Diet. Doctors from the Paris hospital Pitie Salpetriere, found that 75% of those on the Dukan Diet regained the weight they’d lost on the diet, within 2 years. Dr Boris Hansel (a metabolism and cardiac specialist) spoke on behalf of this group of doctors, in Le Parisien newspaper:

“The Dukan Diet is not a long term success because it doesn’t meet our body’s needs. There are real risks: infertility, sleep apnoea, high blood pressure, type 2 diabetes, liver disease, cardiac problems. Following this diet is not harmless, it could cause real health problems.”

Dr Hansel went on to call for a proper scientific study to evaluate the Dukan Diet on public health grounds. I agree with Dr Hansel. It’s strange that there has never been a properly funded, large scale, scientifically rigorous study of any best-selling diet, ever. There have been small studies, involving few people, over very short periods, but nothing scientifically rigorous. I guess it’s not in the interests of any promoters of these diets to fund such a study, and no government has ever been pro-active enough to investigate the public health effects of diets followed by millions.

But surely the Dukan Diet is safe and effective, claim its supporters. It has celebrity endorsements! Personally I think celebrity endorsement of diets should set alarm bells ringing, and the more celebrities endorse it, the more reason not to touch the diet with a barge-pole. Penelope Cruz, Jennifer Lopez, and Kate Middleton, have all reportedly followed the Dukan Diet. However, I’m not saying that Kate Middleton’s severe morning sickness had anything to do with her nutrition regime.

Supporters of the diet also point to the weight loss success stories. But how much of that weight loss is body fat, and how much is water, glycogen stores, and bone density loss? And how many of those success stories have regained any fat lost, in the months and years after coming off the diet?

Surely the only true measure of success when it comes to eating and weight loss is that you lose excess body fat and keep it off long term, you don’t risk any adverse health consequences or unpleasant side-effects, and that you’re not deprived of any essential nutrients at any time? And that your eating regime is sustainable for the whole of your life. Do any celebrity diets match up to this measure of success?

The American Dietetic Association reviewed the Dukan Diet, and concluded that it was not harmful, but did not recommend it because it causes bad breath and constipation.

Dr Dukan claims that his diet is appropriate for pregnant women. But Irene Margaretis of the French Food Standards Authority disagrees. She says it risks slowing the growth of the baby, and warns that an excess of vitamin A can cause malformations of the foetus. Seafood is rich in vitamin A, and seafood is on the list of recommended protein foods in the Dukan Diet.

Why are so many people so reluctant just to eat a healthy balanced diet as part of a permanent healthy lifestyle? I think it’s mainly down to misconceptions about healthy eating. One of my jobs as a personal trainer is to show my London clients that healthy eating is definitely not boring, tasteless, restrictive, too expensive, or impractical. And just because your favourite celebrity does something, that’s not necessarily a good reason for you to do it too.

As I always say, it’s far better to eat healthily than to go on a diet.


  • Zoe says:

    Well said Dominic! This kind of diet is definitely ‘in’appropriate for pregnant women.. and all men and women come to that!

  • Zoe says:

    For your members who would like to learn more about truly healthy nutrition, we have some events coming up soon with Dr Brian Clement, Director of The Hippocrates Health Institute – a place where many people go to heal themselves naturally of chronic illnesses. See here for more details: