The Dukan Diet is a controversial and complex diet that is low in calories, carbohydrates and fat but high in protein. It was created by the French physician Dr. Pierre Dukan in the 70’s. Dukan was a family medicine practitioner until 2014 when he lost his medical license in France for breaching ethical regulations.
Here’s everything you need to know about the Dukan Diet, including how it works, and whether it’s a safe and effective way to lose weight.
The Dukan Diet is a low-carb, low-fat, high-protein diet that restricts a number of healthy foods and relies primarily on protein and vegetables. It’s divided into four phases, each with its own set of complex rules.
The first two phases are designed to promote weight loss while the third and fourth phases aim to stabilize weight and maintain a person’s “true weight”. Dukan suggests that a person’s true weight is a healthy, realistic weight that can be maintained for life.
Here’s more about the four phases of the Dukan Diet.
attack phase
The attack phase is the first phase of the diet. How long a person stays in this phase depends on the weight they want to lose, their age, and their diet history. For most people, this phase lasts between two and five days.
Here are the timing recommendations listed on the Dukan website:
- Less than ten pounds to lose: a day or two
- 15 to 30 pounds to lose: three to five days
- More than 40 pounds to lose: After consulting your doctor, this phase can last up to seven days.
During the attack phase, a person can only eat 68 approved high-protein foods, such as skinless chicken breast, eggs, and non-fat dairy products. It is recommended to eat 1.5 tablespoons of oat bran daily to prevent constipation and limit the absorption of calories.
When you are in the attack phase, more physical activity, such as walking, is recommended in the morning.
cruise stage
The cruise phase is meant to be followed until you reach your “true weight”. You’re supposed to follow this phase for three days for every pound you want to lose. If a person has more weight to lose, they will stay in the cruise phase for a longer period of time.
In the cruise phase, all foods from the attack phase are allowed as well as 32 non-starchy vegetables, including zucchini and collard greens, creating a list of 100 allowed foods. It is recommended to alternate days of pure protein (PP) – consisting of eating only foods approved in the attack phase – with days of protein and vegetables (PV). Oat bran is also encouraged during this phase.
It is also recommended to exercise daily to increase fat loss. Dukan recommends brisk walking for 30 minutes daily.
stage of consolidation
The consolidation phase marks the end of the weight loss phases and allows for the introduction of new foods. It is recommended to stay in this phase for ten days for every pound lost. People who lose more weight in the first two phases will stay in the consolidation phase for a longer period of time.
In addition to the 100 foods allowed in the first two phases, cuts of fatty meats and uncooked pork are allowed.
The following chart shows other foods allowed during the consolidation phase. Keep in mind that the consolidation phase is divided into two parts.
| Additions in the first half of the consolidation | Additions in the second half of the consolidation |
| A serving of fruit every day, except for bananas, figs, cherries and grapes | Two servings of fruit each day, with the exception of bananas, figs, cherries and grapes |
| Two slices of whole grain bread daily | Two slices of whole grain bread daily |
| 1.5 ounces of hard cheese | 1.5 ounces of hard cheese |
| One serving (cup cooked) of starchy foods each week | Two servings (1 cup cooked) of starchy foods each week |
| One festive meal per week, consisting of one appetizer, one main course, one dessert, and a glass of wine | Two festive meals per week, consisting of one appetizer, one main course, one dessert, and one glass of wine |
stage of stability
This phase is meant to be followed for life to promote weight stability. There are no forbidden foods, but a person must follow three rules:
- Eat three tablespoons of oat bran every day
- Have one pure protein day a week where you only eat Phase 1 foods
- Use the stairs and avoid elevators and escalators
Dukan recommends that dieters sign up for training through the Dukan website in order to increase the chances of long-term weight loss success.
Any diet that significantly restricts calories will result in weight loss, so someone on a highly restricted Dukan diet will likely experience fat loss.
There aren’t a lot of studies that have looked at the effects of the Dukan diet on weight loss, but one 2015 study found that women who followed the Dukan diet for eight to 10 weeks lost an average of 33 pounds.
However, researchers did find some major problems with the diet, such as inadequate levels of vitamins and minerals and excessive protein intake. Furthermore, it was thought that the reason for the dramatic weight loss was due to the extremely low calorie content of the diet.
The study found that women who followed the Dukan diet ate only 888 calories per day during the first phase of the diet and about 1,000 calories per day during the other phases. Any low-calorie diet will lead to rapid weight loss, but it is not a healthy or sustainable way to lose weight.
The study didn’t follow the women long-term, but it’s possible that the weight they lost did come back on over time. Studies show that people who lose weight after following restrictive diets usually regain all or most of the weight they initially lost.
In addition to weight loss, the Dukan Diet may also cause a short-term decrease in blood sugar and blood lipid levels. However, this is due to the severe calorie restriction and rapid weight loss that this diet encourages, not necessarily the diet itself.
There is currently not enough evidence to support the use of the Dukan Diet to promote weight loss or improve other health indicators. Since the diet is very restrictive and not based on sound science, it is best to avoid this diet and instead opt for more evidence-based approaches to improving health.
The Dukan diet is very restrictive and drastically cuts calories, which can lead to several health risks.
A 2014 case study reported that a woman on the Dukan diet was hospitalized because she had uncontrollable vomiting secondary to ketoacidosis. Diet-induced ketoacidosis is a rare condition caused by a lack of glucose, or blood sugar, in the body.
While you are unlikely to experience ketoacidosis when following the Dukan Diet, this eating pattern can lead to a variety of unpleasant and potentially dangerous side effects.
Studies show that drastically reducing calories and carbohydrates can lead to side effects such as dizziness, irritability, headaches, fatigue, extreme hunger, low blood sugar, and constipation.
Furthermore, the 2015 study mentioned above found that women who followed the Dukan Diet had lower intakes of several nutrients, including vitamin C, potassium, calcium, and folate, and that they were consuming excessive amounts of protein, phosphorus, and sodium.
Because it is highly restrictive and low in calories, the Dukan Diet is not appropriate for children and teens, pregnant or nursing women, and those with certain medical conditions, such as eating disorders and low blood pressure.
There are many other weight loss-friendly eating patterns that are safer and less restrictive than the Dukan Diet and that provide your body with the nutrients it needs to function optimally. If you want to lose weight or improve other health parameters, it is best to choose a nutritious, evidence-based diet such as the Mediterranean diet or a whole plant-based diet.
The Dukan Diet is a low-carb, low-fat, high-protein, low-calorie diet. It is divided into four phases, most of which are very restrictive.
It can potentially lead to weight loss in the short term, but it is not based on sound science and may lead to many side effects, which can be dangerous.
If you’re interested in losing weight, consider eating a more sustainable diet that doesn’t involve severe calorie restrictions or rely on arbitrary and complex rules.
If you need help choosing an effective weight loss plan, consider working with a registered dietitian to come up with a plan that is safe and healthy for your body.