Known as the man who helped Kate Middleton drop two dress sizes in time for her big day, it's no surprise that his book The Dukan Diet quickly shot up the charts in the UK. But the French nutritionist doesn't come without his share of controversy.
Involved in several high profile scandals, including the time he suggested 17-year-olds take a test which they could pass by keeping an appropriate weight, Dukan faced several disciplinary actions during his time as a doctor, and was eventually struck off the medical register in 2014.
But in his first publication since 2014, "The 60 most important days of your pregnancy", Dukan's advice focuses on healthy eating rather than weight loss.
And unsurprisingly the release has caught the attention of the French media.
"When I look at the statistics for obesity around the world, I see there are millions of people dangerously overweight and suffering," Dukan told The Local. "The population has completely transformed since the 1970s."
In short, during months four and five of pregnancy Dukan advises women to reduce their intake of certain foods, particularly refined sugar. During these months, the baby's pancreas is developing and learning to produce insulin.
The nutritionist sums up his recommendations as "eating like your grandma". And while this description may make a lot of sense, considering his diet advises eating fruit rather than fruit juice and whole grain rice as an alternative to white rice, some have criticised the book as too simplistic.
In an interview with L'Obs, Jean Michel Lecerf, head of the nutritional organisation, Pasteur Institute in Lille went further, calling it "simplistic and worrying" and highlighted the "lack of serious proof" of the link between the mother's intake of sugar and the health of the baby's pancreas.
Lercerf, the man behind the 2010 report for ANSES - the French Agency for Food, Environmental and Occupational Health & Safety, on the risks linked to weight reducing diets, with a particular focus on the Dukan diet, admits that the book offers some worthwhile, if already well-known, advice.
But added, "If I was a pregnant women, reading this book would make me panic," explaining that the focus on 60 days when everything is played out is anxiety-inducing.
Dukan, on the other hand, defends his "simplistic" method: "Some people find themselves paralysed by the complexity of nutrition. I say that the science behind what I'm recommending is complex, but the advice is easy to follow, and that's how it should be.
"I don't need to worry about research donations like others, so I'm not hampered by the industry," he told The Local, adding that he hopes the book will be published in English soon.