What Is the Dukan Diet?

The Dukan diet is a diet is a controversial, complicated diet that’s low in calories, carbs, and fat, but high in protein. It was created by French physician Dr. Pierre Dukan in the 1970s. 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 if it’s a safe and effective way to lose weight. 

How Does the Dukan Diet Work?

The Dukan Diet is a low-carb, low-fat, high-protein diet that restricts a number of healthy foods and is primarily based on protein and vegetables. It’s split into four phases, each with its own set of complicated rules.

The first two phases are designed to promote weight loss while phases three and four are meant for weight stabilization and maintaining a person’s “true weight.” Dukan suggests that a person’s true weight is a healthy and realistic weight that can be maintained for life.

Here’s more about the four phases of The Dukan Diet. 

The 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 wish to lose, their age, and their dieting 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: one or two days 
• From 15 to 30 pounds to lose: three to five days
• More than 40 pounds to lose: after consulting with your physician, this phase can last up to seven days.

During the Attack Phase, a person can only eat 68 approved high-protein foods, like skinless chicken breast, eggs, and nonfat dairy products. It’s recommended to consume 1.5 tablespoons of oat bran per day to prevent constipation and limit calorie absorption.  

When in the Attack Phase, it’s recommended to add in physical activity, like walking, in the morning. 

The Cruise Phase

The Cruise Phase is meant to be followed until you reach your “true weight.” You’re meant to follow this phase for three days for every pound you want to lose. If a person has more weight to lose, they’ll stay in the Cruise Phase for a longer time period.

On the Cruise Phase, all of the foods from the Attack Phase are allowed plus 32 non-starchy vegetables, including zucchini and greens, which creates a list of 100 allowed foods. It’s recommended to alternate days of pure protein (PP)—which consists of eating only foods approved in the Attack Phase—with protein and vegetable days (PV). Oat bran is also encouraged during this phase.

It’s also recommended to exercise daily to boost fat loss. Dukan recommends 30 minutes of brisk walking per day. 

The Consolidation Phase

The Consolidation Phase marks the end of the weight loss phases and allows the introduction of new foods. It’s recommended to stay in this phase for ten days for every pound lost. People who lose more weight in the first two phases will remain in the Consolidation Phase for a longer time period. 

In addition to the 100 foods allowed in the first two phases, fattier cuts of meat and uncured cooked ham are allowed. 

The following chart explains the other foods permitted during the consolidation phase. Keep in mind that the Consolidation Phase is split into two parts.

The Stabilization Phase

This phase is meant to be followed for life to promote weight stabilization. No foods are off limits, but a person must follow three rules:

1. Eat three tablespoons of oat bran every day
2. Have one Pure Protein day per week where you only eat foods from phase one
3. Take the stairs and avoid taking elevators and escalators 

Dukan recommends that dieters sign up for coaching through the Dukan website in order to increase the chances of long-term weight loss success. 

Is the Dukan Diet Effective?

Any diet that significantly limits calories will result in weight loss, so it’s likely that a person following the highly restrictive Dukan Diet will experience fat loss. 

There are not a lot of studies that have looked into 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, the researchers found some major issues with the diet, like inadequate vitamin and mineral levels and excessively high protein intake. What’s more, the reason for the significant weight loss was thought to be caused by the extremely low-calorie content of the diet.

The study found that the women who followed The Dukan Diet were taking in just 888 calories per day during the first phase of the diet and around 1,000 calories per day during the other phases. Any diet that is this low in calories will result in rapid weight loss, but it’s not a healthy or sustainable way to lose weight.

The study didn’t follow the women long-term, but chances are the weight they lost was gained back over time. Studies show that people who lose weight following restrictive diets usually gain back all or most of the weight they initially lost. 

In addition to weight loss, The Dukan Diet may also lead to short-term reductions in blood sugar and blood lipid levels. However, this is due to the extreme calorie restriction and the rapid weight loss encouraged by this diet, not necessarily the diet itself. 

There’s currently not enough evidence to support the use of The Dukan Diet for promoting weight loss or improving other markers of health. Because the diet is so restrictive and not based on sound science, it’s best to avoid this diet and instead choose more evidence-based methods to improve health. 

Is the Dukan Diet Safe?

The Dukan Diet is highly restrictive and significantly cuts calories, which can lead to several health risks.

A 2014 case study reported that a woman following The Dukan Diet was hospitalized because she was experiencing 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 it’s unlikely you’ll experience ketoacidosis when following The Dukan Diet, this eating pattern could lead to a variety of other unpleasant and potentially dangerous side effects.

Studies show that cutting calories and carbs too significantly can lead to side effects like dizziness, irritability, headaches, fatigue, extreme hunger, low blood sugar, and constipation.

What’s more, the 2015 study mentioned above found that the women following The Dukan Diet had low 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’s so restrictive and low in calories, The Dukan Diet isn’t appropriate for children, teens, pregnant or breastfeeding women, and those with certain medical conditions, like 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’d like to lose weight or improve other health parameters, it’s best to choose an evidence-based, nutritious diet like the Mediterranean diet or a whole foods, plant-based diet. 

A Quick Review

The Dukan Diet is a low-carb, low-fat, high-protein diet that’s low in calories. It’s split into four phases, most of which are excessively restrictive. 

It will likely lead to short-term weight loss, but it’s not based on sound science and may lead to several side effects, which could be dangerous. 

If you’re interested in losing weight, consider following a more sustainable diet that doesn’t involve extreme calorie restriction or rely on arbitrary and complicated rules. 

If you need help choosing an effective weight loss plan, consider working with a registered dietitian to come up with a plan that’s safe and healthy for your body.