Dukan Diet for Weight Loss: What Is It, Pros and Cons

The Dukan diet is another popular plan that promises fast weight loss without hunger. Although it seems easy, the Dukan diet is restrictive and costly, making it harder to sustain.

To date, there is neither a superior weight loss diet nor an end to new ones emerging. Some are entirely against healthy and balanced nutrition, some have little evidence, and others have a solid scientific background. Which category does the Dukan diet fall into?

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Dukan Diet: What Is It?

The Dukan diet is a high-protein, low-carbohydrate eating plan created by French doctor Pierre Dukan in 2000. There is no calorie restriction, and 20 to 30 minutes of exercise is required for the program. It involves limiting particular foods or food groups at various stages.¹

Phases of the Dukan Diet

The Dukan Diet consists of four stages: the first two focus on weight loss, while the remaining two aim to maintain the so-called "true weight." The phases of the Dukan diet include:²

1. Attack Phase

The Attack phase emphasizes high protein intake. You can only consume lean protein sources such as lean meat, poultry, seafood, organ meats, fat-free dairy products, eggs, and vegetarian protein options like tofu, tempeh, and seitan.

The first phase can last from 1 to 10 days. One and a half tablespoons of oat bran and 20 minutes of daily exercise are also part of this phase.

2. Cruise Phase

In the Cruise phase, you add unlimited non-starchy vegetables to your meals. However, you should alternate between protein-only days and days that mix protein with permitted vegetables. The ratio can be 5:5 (five days of only protein followed by five days of a mix of protein and allowed vegetables) or 1:1 (one day of only protein followed by a day mixing protein and vegetables).

This stage lasts three days for every pound you wish to lose. For example, if you want to lose 5 pounds, the Cruise phase will last 15 days. Two tablespoons of oat bran and 30 minutes of exercise are also included in this phase.

3. Consolidation Phase

The Consolidation phase is about gradually reintroducing previously forbidden foods in smaller quantities. In this stage, starchy vegetables, whole grains, cheese, and fruits are allowed in limited amounts. Additionally, two "celebration meals" per week are permitted. Two and a half tablespoons of oat bran and 25 minutes of exercise are also part of this phase.

The length of this stage depends on the weight lost during the Cruise phase. For every pound lost, five days of the Consolidation phase are required. One day per week should still be protein-only.

4. Stabilization Phase

The Stabilization phase is lifelong. The final stage requires maintaining the same eating pattern, with one protein-only day per week, alongside a 20-minute walk and three tablespoons of oat bran daily.

You should drink plenty of water in all phases and monitor your salt intake.

<div class="pro-tip"><strong>Also Read: </strong><a href=protein-for-weight-loss>Protein for Weight Loss: 5 Science-Backed Benefits + Foods</a></a>.</div>

Pros and Cons of the Dukan Diet

As with any eating plan, the Dukan diet has pros and cons. Evaluating these is important to determine whether it is suitable for your health.

If you decide to try this diet, be aware that scientific evidence is very limited. For this reason, it's best to consult your healthcare provider before adopting the diet to manage any potential health risks.

Pros

Possible pros of the Dukan diet may include:

• The Diet Enhances Water and Protein Consumption: The Dukan diet mainly consists of high-protein foods, so you will hit your daily protein intake and maybe exceed it. The diet also emphasizes water intake. Drinking enough water is especially important on a high-protein diet because your kidneys work harder to process the increased protein intake.‍
• The Dukan Diet Promotes Exercising: Daily 20 to 30 minutes are mandatory in the Dukan diet. Regular exercise, both aerobic and strength exercise, is beneficial for both physical and mental health. It helps prevent and manage chronic diseases such as heart disease and diabetes.³‍
• The Diet May Promote Weight Loss: You may have seen success stories represented on the Dukan diet website. Although the Dukan diet has been popular, there is very little evidence showing that the diet can reduce body weight.⁴
• ‍The Dukan Diet Can Improve Satiety: The Dukan diet is a high-protein diet, which can help maintain muscle mass and promote satiety while losing weight.⁵‍
• The Diet Discourages the Consumption of ​​Alcohol, Sugar, and Processed Foods Consumption: The diet doesn't forbid processed foods, sugar, or alcohol, but it discourages them because they can hinder weight loss.  

Cons

Possible cons of the Dukan diet may include:

• The Dukan Diet Can Cause Nutrient Deficiencies: Although the Dukan diet doesn't forbid any foods for good, it limits the consumption of certain foods such as grains, beans, lentils, fruits, full-fat dairy, and nuts. Limiting these foods can cause nutrient deficiencies in the long term. Also, a high-protein diet can increase urinary calcium, posing a risk to bone and kidney health. Even Dr. Dukan recommended taking vitamins during restrictive phases.⁵‍
• The Diet Is Highly Restrictive: The Dukan diet is promoted as a no-calorie-restriction diet. Although it doesn't restrict calories, it forbids certain foods for a period and then discourages eating more than certain portions of those foods. This kind of eating pattern is not suitable for most people.
• Restrictive Diets Can Overlook the Mental Aspects of Dieting: Our nutrition can change daily based on many factors, including available time, activity levels, menstruation status, and emotional well-being. Trying to adhere to the same eating patterns every day can be stressful for some people, which can lead to unhelpful negative thoughts about healthy eating and body image.⁶‍
• People With Heart Diseases Will Lack Enough Fiber: The Dukan diet doesn't restrict vegetables, but it restricts other fiber sources such as whole grains, beans, and lentils. Enough fiber can help prevent heart disease, stroke, type 2 diabetes, and bowel cancer.⁷

There are two types of fiber: soluble and insoluble. Dr. Dukan recommends oat bran alongside diet; however, oat bran is primarily soluble fiber. However, we need both types of fiber—soluble fiber helps lower blood lipid levels, while insoluble fiber supports digestive health. Consuming various fiber-rich foods, including fruits, vegetables, whole grains, and legumes, helps ensure you get both soluble and insoluble fiber.

• The Diet Can Cause Health Problems Due to Rapid Weight Loss: Rapid weight loss is desirable for many people. However, your body needs time to adjust to new eating patterns and weight changes. Losing weight too quickly can lead to muscle mass loss and a decreased basal metabolic rate. However, on the other hand, a high-protein diet can prevent muscle loss and increase basal metabolic rate.^{8, 9}

Rapid weight loss can also cause other health conditions, such as gallstone formation, hair loss, and cold intolerance. Losing more than 10% of body weight is considered significant weight loss. Most healthcare providers recommend losing 1 to 2 pounds (0.5 to 1 kg) weekly for healthy and sustainable weight loss.⁵

• The High Protein Content May Not Be Suitable for People With Kidney Disease: High-protein diets, like the Dukan diet, can be a concern because eating a lot of animal proteins might increase uric acid and calcium in your urine and decrease another substance called citrate.¹º This can raise the risk of kidney stones.⁴‍
• ‍The Dukan Diet Can Cause Tiredness, Constipation, Headaches, Bad Breath, and Dry Mouth: Dr. Dukan mentioned the possible side effects of the diet. Due to increased protein and decreased carbohydrate intake, you can experience side effects including but not limited to dizziness, tiredness, constipation, headaches, nausea, dry mouth, and bad breath. 

Side effects can even be life-threatening. A case study showed that a 42-year-old woman was admitted to the hospital with nausea, vomiting, and ketoacidosis after 2 days of starting the Dukan diet. Ketoacidosis is a condition where the blood becomes too acidic and is considered an emergency.¹¹

People with diabetes are especially prone to ketoacidosis when there is a lack of glucose in the blood. If you have chronic diseases, be especially cautious with the Dukan diet, and don't start it without the supervision of your healthcare provider.

• The Dukan Diet May Not Be Ideal Regarding Sustainability Due to Its Restrictive Nature and Cost: The diet can be costly since it includes more high-protein foods, supplements like oat bran, and sometimes vitamins. It limits the consumption of more affordable foods or food groups such as grains, lentils, beans, and fruits.

Dukan Diet: What to Eat

The Dukan diet requires a specific eating plan. Only certain foods are permitted at some stages of the diet. In the book, Dr. Dukan gives a food list consisting of 100 foods. Foods allowed in the Dukan diet may include but are not limited to:

• Attack Phase: Lean meats, organ meats, low-fat ham, poultry, smoked turkey, fish, shellfish, soy foods, fat-free dairy products, eggs, coffee, tea, and vinegar.
• Cruise Phase: All raw and cooked vegetables (except starchy vegetables), such as tomatoes, carrots, cucumbers, mushrooms, green beans, spinach, cabbage, zucchini, peppers, eggplant, and beets.
• Consolidation Phase: You can consume all foods in the Attack and Cruise phases. Additionally, one serving of fruit, two slices of whole grain bread, one serving of hard cheese, and two servings of starchy foods (potatoes, pasta, lentils, legumes, rice, corn, etc.) are permitted.
• Stabilization Phase: Foods from the Attack and Cruise phases are always encouraged. Limitations are recommended for the remaining food groups. The book recommended restricting some foods to certain amounts, such as one piece of fruit, two slices of 100% whole grain bread, 40 grams of cheese, and two portions of starchy foods daily. Also, two "celebration meals" per week are permitted.

Foods to Avoid on a Dukan Diet

The Dukan diet eliminates certain foods or food groups for a limited time or permanently discourages them, such as refined sugars and processed foods. Foods forbidden in the Dukan diet may include but are not limited to:

• Attack Phase: Oils, fatty meats, grains, vegetables, fruits, nuts, and seeds. In short, all foods except lean meats, poultry, seafood, fat-free dairy, and eggs are forbidden in this phase.‍
• Cruise Phase: Starchy vegetables such as corn and potatoes. Grains (such as wheat, rice, quinoa, barley, and millet), fresh or dried peas, beans, lentils, and nuts are also forbidden at this stage.‍
• Consolidation Phase: Fruits with higher sugar content, such as dried fruits, bananas, grapes, and cherries, are discouraged.‍
• Stabilization Phase: No foods are forbidden except on one day of the week when you can only eat proteins such as lean meats, organ meats, low-fat ham, poultry, fish, shellfish, soy foods, fat-free dairy products, and eggs.

Is the Dukan Diet Good for You? 

Although fast weight loss without restricting calories is highly desirable for most people, quick weight loss with a high-protein, low-carb diet can cause undesirable health outcomes such as loss of muscle mass, gallstone and kidney stone formation, hair loss, dizziness, constipation, headaches, and bad breath. The diet is also not the easiest to sustain, considering the higher cost of foods and restrictions.

If you're considering starting the Dukan diet, be aware of the possible health risks. Consulting your healthcare provider and seeking assistance while following the diet can help prevent health problems.

Learn More About How to Improve Blood Sugar Health With Signos' Expert Advice

Diabetes management commonly involves medication and lifestyle changes. While choosing proper medication for an individual, healthcare providers consider many factors, such as blood sugar management, eating habits, lifestyle, and general health. 

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Learn more about diabetes management following Signos' blog. You'll find articles on blood glucose and diabetes curated by Signos experts.

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