That dukan diet is full of crap. I never trust them, because in the end of the day they always lie to the clients, by making them think that they lose weight due to the healthy foods, but they just sell you shitty food of theirs.
If you want to get on diet, then get on such a diet where you can have your own meals. For example, follow the carb cycling diet - it is very effective for fat loss, and at the same time it is easy to follow because it is not restrictive, so you can basically eat a wide variety of foods. It is very healthy, and you can have it as a lifestyle, not as a temporary diet.