The Dukan Diet, a high-protein, low-carbohydrate diet, was created by French physician Pierre Dukan. It gained popularity after reports linked it to Kate Middleton’s pre-wedding weight loss routine. The diet is built around lean protein and non-starchy vegetables, with limited room for fats and carbohydrates, but does feature a few other foods, such as olive oil and oat bran.
What is the Dukan Diet?
The Dukan Diet is a weight-loss plan that emphasizes high protein, low carbohydrates, and low fat. Followers rotate through four structured phases with specific food rules for each phase. The early stages are especially strict, with the later phases gradually reintroducing certain foods to support long-term weight maintenance.
The Core Principles
At its core, the Dukan Diet is a high-protein, low-carb diet. It involves moving through four phases that are specially designed to help you lose weight, get to your goal weight, and learn to eat healthier along the way. The Dukan Diet encourages you to focus on protein before adding in whole grains, fruits, and carbs. The idea is to reset your palate so you are satisfied with healthy meals and reduce cravings for less healthy fare.
The Four Phases of the Dukan Diet
The Dukan Diet is structured into four distinct phases, each with its own set of guidelines and goals.
Attack Phase
The Attack phase is the first and most restrictive phase of the Dukan Diet. It typically lasts two to five days, but it can last up to seven days (after the okay from your physician) for those with more than 40 pounds to lose. During this phase, dieters are encouraged to consume only lean protein, a small amount of oat bran for fiber, and plenty of water. The purpose of this phase is to kickstart weight loss and water loss, motivating you to continue on to the next phase. Also known as the Pure Protein phase, you can enjoy unlimited low-fat, high-protein foods, including lean beef, pork, poultry, non-fat dairy, eggs, fish, and tofu. You’re also allowed to eat 1.5 tablespoons of oat bran per day. According to Dr. Dukan, the oat bran is meant to reduce cholesterol and help prevent diabetes, but it’s also there to add fiber to your diet and promote satiety.
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Cruise Phase
The Cruise phase introduces non-starchy vegetables into the diet, alternating between pure protein days and protein-vegetable days. After several days on phase 2, you’ll reintroduce non-starchy vegetables, such as cucumbers, mushrooms, spinach, asparagus, and broccoli. Dieters stay in this phase until they reach their True Weight. This phase is designed to produce weight loss at a steady pace of about two pounds per week until you reach your desired weight. The Cruise phase can last several weeks or even months, depending on your weight loss goals. You will alternate between protein-only days and protein-vegetable days, along with two tablespoons of oat bran daily.
Consolidation Phase
The Consolidation phase is crucial for preventing rebound weight gain. This phase is designed to prevent the rebound effect of gaining back the pounds lost during the first two phases. In this phase, you’ll gradually reintroduce foods that were previously restricted, such as fruits, whole grains, and cheese. During this phase, foods that were previously restricted are gradually added in limited quantities. You will continue to follow a protein-vegetable diet and consume two tablespoons of oat bran daily. Once a week, you are required to follow a Pure Protein day from the Attack phase. Phase 3 lasts five days for every pound lost. The length of the Consolidation phase depends on how much weight was lost. You’ll typically stay in this phase for five days per pound lost. So, if you lost 20 pounds, this phase will last 100 days. One to two “celebration meals” are allowed per week (depending on where you are in this phase). Celebration meals consist of an appetizer, entree, dessert and a glass of wine. “Celebration meals” are followed by a return to stricter eating. Moreover, during the Consolidation phase, you can eat one to two servings of fruit (excluding bananas, grapes, figs, and cherries) and two slices of whole-grain bread per day. You're also allowed to consume 1.5 ounces of hard cheese, one to two servings of starchy food, and one to two celebration meals per week. A celebration meal includes an appetizer, entrée, dessert, and one glass of wine.
Stabilization Phase
The Stabilization phase is the final, lifelong phase of the Dukan Diet. The primary goal here is to maintain the weight loss you achieved. On this final phase (aka the rest of your life), you can eat whatever you want along with three tablespoons of oat bran per day. As in the phase 3, a Pure Protein day is required once a week. In this phase, you’re encouraged to follow three simple rules: Consume three tablespoons of oat bran daily, have one pure protein day per week and avoid taking the elevator or escalator-opt for stairs whenever possible. This phase offers more flexibility but requires an ongoing commitment to the principles learned during the other phases. Throughout all phases of the diet, Dr. Dukan recommends drinking six to eight cups of water daily.
Foods You Can Eat
Most meals on the Dukan Diet are built around lean protein due to its appetite-curbing effects. Here are some of the foods you can eat:
- Lean meats: Chicken, turkey, and lean cuts of beef or pork
- Seafood: Salmon, cod, sardines, shrimp, mussels
- Vegetarian protein sources: Tempeh, tofu, seitan, veggie burgers and other faux meats
- Nonfat dairy products: Yogurt, cottage cheese and milk
- Eggs
- Non-starchy vegetables: Spinach, broccoli, cauliflower, zucchini, etc.
- Additional foods: Shiritiaki noodles, small portions of oat bran and olive oil
Foods You Can't Eat
Because the Dukan Diet begins with a highly restrictive stage, many everyday staples are off limits at first. Later phases allow some of these foods back in small, carefully measured amounts, but the earliest phase requires strict avoidance. Here’s what’s off the menu:
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- Grains and cereals: Bread, pasta, rice and most other grains (except for the small daily serving of oat bran) are excluded
- Starchy vegetables: Potatoes, corn, peas and similar vegetables
- Fruits: Apples, berries, pears, bananas and other fruits are not permitted initially because they contain natural sugars
- Sugary foods and beverages: Desserts, candy, pastries, sodas and other sweetened drinks are strictly off limits
- Alcohol: All forms of alcohol are excluded in the early phases
- Most sources of fat: Nuts, seeds and full-fat dairy are avoided. Only small amounts of olive oil are eventually allowed
Pros of the Dukan Diet
As a registered dietitian, I think there’s more to dislike about this diet than to like about it. That said, there are some aspects that people may find beneficial.
Clear Structure and Simple Rules
The plan’s four defined phases and strict food lists remove guesswork. With no calorie counting or detailed tracking required, many people find it easier to follow than diets that demand constant monitoring. This structured approach can also lessen decision fatigue, which often derails healthy eating efforts.
Emphasis on Protein
Because protein is naturally satiating and helps preserve muscle, meals built around lean protein may reduce hunger and cravings while supporting metabolism during weight loss. Research consistently shows that protein-rich eating patterns can help with appetite control and muscle maintenance when calories are reduced.
Early Weight Loss Wins
The initial phase is likely to lead to quick fluid and weight loss. This early drop can be motivating and provide a mood boost to continue with lifestyle changes.
No Tracking Needed
Some people will appreciate that the Dukan Diet eliminates the need to track calories, focusing instead on food choices. However, in later phases, you’ll need to pay close attention to portion sizes of the foods being reintroduced.
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Cons of the Dukan Diet
The Dukan diet has significant drawbacks that need to be considered.
Nutrient Gaps and Low Fiber
The first phase is especially restrictive. As a result, key vitamins, minerals, and antioxidants from fruits, vegetables, whole grains, nuts and seeds are missing, which can undermine both short- and long-term health. Additionally, in the initial Attack phase, the recommended 1 ½ tablespoons of oat bran provides less than 2 grams of fiber per day of the 21 to 38 grams needed daily for optimal health. Because the diet restricts so many healthy foods, it’ll be nearly impossible to meet your nutrient needs to maintain health, let alone thrive.
Difficult To Sustain
The limited food choices, particularly in the early phases, can make the diet repetitive and difficult to stick to long-term. Granted, this is also part of what may make the diet appealing because too many choices can feel overwhelming. But, over time, it can become more challenging to follow the rules, particularly in social circumstances, like happy hour with friends or travel with family. When a diet is so restrictive, you may be inclined to give up, which can result in feelings of shame and failure, when in reality, the diet is unsustainable - it’s not your fault.
Problematic Food Messaging
I also have an issue with celebration meals because this concept promotes the idea of all-or-nothing thinking - that you’re either eating healthfully or not - which can negatively impact your mental health and prevent you from learning how to regularly allow these foods in a healthy and balanced way. Research published in 2022 found that so-called cheat meals, technically defined as brief episodes of eating prohibited foods, are associated with disordered eating behaviors. This approach can harm your relationship with food and make it harder to practice balanced, flexible eating. A healthier mindset is to regularly allow moderate amounts of less nutrient-dense foods - like enjoying a slice of pizza with friends. This supports both mental well-being and long-term nutrition goals.
Other Drawbacks
The Dukan Diet can result in significant weight loss, especially for those who are very overweight or obese. However, the diet is very rigid and restrictive, especially during the first two phases. And because you’re restricting major food groups, like fruits, healthy fats, and vegetables, it can lead to nutritional deficiencies. In the long-term, a high-protein, low-carb diet may also harm the kidneys, as they need to work harder to metabolize such high intakes of protein. You may also experience common side effects of a low-carb diet, like headaches, lethargy, and constipation.
Exercising While on the Dukan Diet
Exercise is encouraged on the Dukan Diet, though the intensity and type may vary depending on the phase. During the initial Attack phase, light walking is encouraged. As the diet progresses, you’ll up the intensity with brisk walking. The Dukan Diet suggests a minimum of 20 minutes of exercise in the Attack phase and 30 minutes in later phases. However, the CDC recommends a minimum of 150 minutes of moderate-intensity activity per week, which equates to 30 minutes of cardio exercise five times a week. They also advise two days of muscle-strengthening activities (such as lifting weights or doing push-ups, squats and other muscle-toning exercises) each week.
Is the Dukan Diet Effective?
The Dukan Diet claims you can lose up to 10 pounds during the first week of following the diet, but since it’s a strict plan, it can be difficult to sustain long-term. The Dukan Diet lacks specific scientific research to support its claims, efficacy, and long-term effects on overall health. However, there have been studies that suggests that high-protein, low-carb diets are effective for weight loss in the short-term. A May 2018 study from Applied Physiology, Nutrition, and Metabolism suggests that low-carb diets, such as the Dukan Diet, are effective for helping women with prediabetes reduce their risk of heart disease. However, it’s important to note that most studies researching the effects of high-protein, low-carb diets do not include restricting dietary fats as outlined in the Dukan Diet. So it’s harder to assess the effects of the diet both short- and long-term. More research and evidence is needed to support the claims that following low-carb, high-protein, low-fat diets, such as the Dukan Diet, are safe and effective for weight loss.
Is the Dukan Diet Right for You?
Because the Dukan Diet is heavy on protein, it can help keep you from losing muscle-a big trap many people fall into with diets. Individuals that are interested in losing some weight but are looking to maintain muscle mass are a good fit for this diet. But the Dukan Diet isn’t really great for long-term weight loss success. This diet would work for someone who wants to lose weight quickly and doesn’t care if the weight comes back on quickly after such a restrictive diet. You have to be willing to eat very restrictive foods if you want to lose weight and keep it off.
How to Get Started
Before starting the Dukan Diet, you must establish your goal weight, which Dr. Dukan refers to as your “True Weight.” The True Weight will determine how long you’ll stay on each of the first three phases of the diet. To prepare for the Attack phase, be sure to stock your kitchen with approved foods. The Dukan Diet site is a great resource for more details of each phase of the diet, and it includes a robust FAQ section, as well as customized coaching for the first three phases of the diet. Before starting the Dukan Diet, it’s important to consult with a primary care physician, especially people with pre-existing conditions including diabetes, heart disease, kidney disease, or anyone prone to kidney stones. Pregnant and breastfeeding women should also avoid this diet.