The Dukan Diet starts by calculating your goal weight — called your “true” weight — based on your age, weight loss history, and other factors.

How long you stay in each phase depends on how much weight you need to lose to reach your “true” weight.

These are the four phases of the Dukan diet:

1. Attack phase (1–7 days): You start the diet by eating unlimited lean protein
   plus 1.5 tablespoons of oat bran per day.
2. Cruise phase (1–12 months): Alternate lean protein one day with lean protein and non-starchy veggies the next, plus 2 tablespoons of oat bran every day.
3. Consolidation phase (5 days for every pound lost in phases 1 and 2): Unlimited lean protein and veggies, some carbs and fats, one day of lean protein weekly, 2.5 tablespoons of oat bran daily.
4. Stabilization phase (indefinite): Follow the Consolidation phase guidelines but loosen the rules as long as your weight remains stable. Oat bran is increased to 3 tablespoons per day.

As shown above, the diet is divided into two weight loss phases and two maintenance phases.

Dukan Diet food list

Each phase of the Dukan Diet has its own dietary pattern. Here’s what you’re allowed to eat during each.

Attack phase

The Attack phase is primarily based on high protein foods, plus a few extras that provide minimal calories:

• lean beef, veal, venison, bison, and other game
• lean pork
• poultry without skin
• liver, kidney, and tongue
• fish and shellfish (all types)
• eggs
• nonfat dairy products (restricted to 32 ounces or 1 kg per day), such as milk, yogurt, cottage cheese, and ricotta
• tofu and tempeh
• seitan, a meat substitute made from wheat gluten
• at least 6.3 cups (1.5 liters) of water per day (mandatory)
• 1.5 tablespoons (9 grams) of oat bran daily (mandatory)
• unlimited artificial sweeteners, shirataki noodles, and diet gelatin
• small amounts of lemon juice and pickles
• 1 teaspoon (5 mL) of oil daily for greasing pans

Cruise phase

This phase alternates between 2 days.

On day one, people are restricted to foods from the Attack phase. On day two, they’re allowed Attack phase foods plus the following vegetables:

• spinach, kale, lettuce, and other leafy greens
• broccoli, cauliflower, cabbage, and Brussels sprouts
• bell peppers
• asparagus
• artichokes
• eggplant
• cucumbers
• celery
• tomatoes
• mushrooms
• green beans
• onions, leeks, and shallots
• spaghetti squash
• pumpkin
• turnips
• 1 serving of carrots or beets daily
• 2 tablespoons (12 grams) of oat bran daily (mandatory)

No other vegetables or fruits are permitted. Other than 1 teaspoon (5 mL) of oil in salad dressing or for greasing pans, no fat should be added.

Consolidation phase

During this phase, people are encouraged to mix and match any of the foods from the Attack and Cruise phases, along with the following:

• Fruit: one serving of fruit per day, such as 1 cup (100 grams) of berries or chopped melon; one medium apple, orange, pear, peach, or nectarine; or two kiwis, plums, or apricots
• Bread: two slices of whole grain bread per day, with a small amount of reduced fat butter or spread
• Cheese: one serving of cheese (1.5 ounces or 40 grams) per day
• Starches: 1–2 servings of starches per week, such as 8 ounces (225 grams) of pasta and other grains, corn, beans, legumes, rice, or potatoes
• Meat: roast lamb, pork or ham 1–2 times per week
• Celebration meals: two “celebration meals” per week, including one appetizer, one main dish, one dessert and one glass of wine
• Protein meal: one pure proteins day per week, where only foods from the Attack phase are allowed
• Oat bran: 2.5 tablespoons (15 grams) of oat bran daily (mandatory)

Stabilization phase

The Stabilization phase is the final phase of the Dukan Diet. It is all about maintaining the improvements achieved during the earlier phases.

No foods are strictly off-limits, but there are a few principles to follow:

• Use the Consolidation phase as a basic framework for planning meals.
• Continue having one pure proteins meal day every week.
• Never take the elevator or escalator when you can take the stairs.
• Oat bran is your friend. Take 3 tablespoons (17.5 grams) every day.

Here are sample meal plans for the first three phases of the Dukan Diet:

Attack phase

Breakfast

• nonfat cottage cheese with 1.5 tablespoons (9 grams) of oat bran, cinnamon, and sugar substitute
• coffee or tea with nonfat milk and sugar substitute
• water

Lunch

• roast chicken
• shirataki noodles cooked in bouillon
• diet gelatin
• iced tea

Dinner

• lean steak and shrimp
• diet gelatin
• decaf coffee or tea with nonfat milk and sugar substitute
• water

Cruise phase

Breakfast

• three scrambled eggs
• sliced tomatoes
• coffee with nonfat milk and sugar substitute
• water

Lunch

• grilled chicken on mixed greens with low fat vinaigrette
• Greek yogurt, 2 tablespoons (12 grams) of oat bran and sugar substitute
• iced tea

Dinner

• baked salmon fillet
• steamed broccoli and cauliflower
• diet gelatin
• decaf coffee with nonfat milk and sugar substitute
• water

Consolidation phase

Breakfast

• omelet made with three eggs, 1.5 ounces (40 grams) of cheese and spinach
• coffee with nonfat milk and sugar substitute
• water

Lunch

• turkey sandwich on two slices of whole-wheat bread
• 1/2 cup (81 grams) of cottage cheese with 2 tablespoons (12 grams) of oat bran, cinnamon, and sugar substitute
• iced tea

Dinner

• roast pork
• grilled zucchini
• 1 medium apple
• decaf coffee with nonfat milk and sugar substitute
• water

There isn’t much quality research available on the Dukan Diet.

One study in Polish women who followed the Dukan Diet revealed that they ate about 1,000 calories and 100 grams of protein per day while losing 33 pounds (15 kg) in 8–10 weeks (1Trusted Source).

While the observed weight loss may sound promising, it’s important to note that 1,000 calories per day is too low for most women.

The most recent Dietary Guidelines for Americans recommends at least 1,600 calories per day for adult women. In addition to being difficult to maintain, restricting calories can have serious negative effects on health (2Trusted Source).

Additionally, most of the weight loss observed in this study was likely attributable to water loss.

The Dukan Diet’s emphasis on high protein, low carb meals may also contribute to its effectiveness, as research has found that high protein, low carb dietary patterns are effective for short-term weight loss (3Trusted Source, 4Trusted Source, 5Trusted Source).

Several factors contribute to protein’s beneficial effects on weight. Digesting protein burns more calories than digesting carbs or fat, and protein may decrease levels of the hunger hormone ghrelin while also increasing several fullness hormones (5Trusted Source).

However, the Dukan Diet is different from many related high protein diets in that it restricts both carbs and fat. It is a high protein, low carb and low fat diet. However, the rationale for restricting fat on a low carb, high protein diet isn’t based in science.

The initial stages of the Dukan Diet are also low in fiber, despite the fact that a daily serving of oat bran is mandatory.

The servings of 1.5–2 tablespoons (9–12 grams) of oat bran contain less than 2 grams of fiber, which is a very small amount and doesn’t provide the many health benefits. The Daily Value for fiber is more than 10 times this amount, at 28 grams (6Trusted Source).

There are a number of issues with the Dukan Diet regarding its safety and sustainability, which makes it a poor choice overall.

Very few studies have investigated the safety of the Dukan Diet.

However, a 2020 case report noted that two women who lost weight with the Dukan Diet and gastric bypass surgery developed bilateral multiple serous pigment epithelial detachment, a condition that causes changes to the structure of the eye (7Trusted Source).

Unfortunately, that’s far from the only issue with the Dukan Diet.

Excessively restrictive

The Dukan Diet’s complicated rules and restrictive nature may make it hard to follow, and may even contribute to disordered eating in the long run.

Although most people will lose weight in the first two phases, the diet is quite limiting — particularly on the pure protein days.

One older study noted that women on the diet ate 1,000 calories per day, far too few for any adult — even on a weight loss program (1Trusted Source).

Although people on the diet may lose weight when they start out, it’s unlikely they’ll be able to sustain this extremely low calorie level for long, and it may lead to other problems (1Trusted Source).

Nutritionally unbalanced

In addition to the Dukan Diet’s extreme calorie restriction, the strict food rules may lead to inadequate amounts of vitamins and minerals in your diet if you follow the diet for a long time.

Additionally, the Dukan Diet eliminates a number of healthy sources of fiber, such as avocados and nuts, because they’re considered too high in fat. Healthy sources of fiber are good for cholesterol management and digestive health (8Trusted Source).

The diet also discourages high fat foods, which are potentially good for your health.

All in all, the diet promotes an unbalanced approach with insufficient amounts of key macros, including carbs and fat.

Not sustainable long-term

All told, the excessive restrictions and unbalanced nutrient content of the Dukan Diet make it unsustainable to follow long-term.

Studies have shown that excessively restrictive diets can cause changes to hunger and satiety hormones that actually increase hunger and food cravings. Additionally, extremely low calorie diets can decrease your metabolic rate, or how many calories you burn at rest (9Trusted Source).

This could result in rebound weight gain when you discontinue the diet, and you are unlikely to be able to stick to this diet for any significant amount of time because it is so difficult and restrictive.

Potential downsides

In addition to the restrictive nature of the diet that could make it hard to sustain, there are concerns about high protein intake. Many of these concerns relate to the potential impact on kidney and bone health (10Trusted Source).

In the past, it was believed that high protein intake could lead to kidney damage and weakened bones.

However, research is still inconclusive on the risk of high protein intake for people with healthy kidneys, and newer research shows that high protein intake may actually promote stronger bones (11Trusted Source, 12Trusted Source, 13Trusted Source).

That said, people who tend to form kidney stones could see their condition worsen with a very high protein intake. For that reason, these diets are not recommended for anyone with impaired kidney function (11Trusted Source, 12Trusted Source, 13Trusted Source).

In addition, high protein diets generally require more water intake. The Dukan Diet’s recommended 50.7 ounces (1.5 liters) of water is likely too low given the increase in protein, according to an older study (14Trusted Source).

The low recommended water intake could lead to dehydration.

People with kidney problems, gout, liver disease, or other health concerns should speak with a doctor before beginning a high protein diet.

In addition, the Dukan Diet is excessively restrictive and can contribute to disordered eating.

How fast is weight loss on the Dukan Diet?

You are likely to experience rapid weight loss when starting the Dukan Diet. However, it’s so restrictive that it may be difficult to stick with long-term.

This also means you might regain the weight you lost in the early phases once you go back to unrestricted eating habits.

Gradual lifestyle changes, like focusing on eating minimally processed food, as opposed to extreme options, like the Dukan Diet, may help you lose and maintain weight loss.

How much does the Dukan Diet cost?

The Dukan Diet is free to follow, although you will need to purchase oat bran. You can also join a paid Dukan program on the Dukan Diet website for $29.99 per month. However, this is not required to follow the Dukan Diet.