Dukan Diet Explained: Four Phases, Results and What Experts Say

Dukan Diet Explained: Four Phases, Results and What Experts Say

The Dukan diet is a four phase, very high protein plan that can cause fast early weight loss. It is restrictive, has little strong research and needs care.

What is the Dukan diet?

The Dukan diet was created by Pierre Dukan, a French doctor, and became famous after his book was published in the early 2000s. It is a high protein, low carbohydrate, very low fat plan built around a list of 100 foods: 68 lean animal protein foods and 32 vegetables. The plan is divided into four phases, from a fast start to a lifelong maintenance routine.

The central idea is that protein is filling and costs more energy to digest, so eating mostly protein, with very little carbohydrate and fat, leads to quick weight loss. Followers are told they can eat as much as they want from the allowed list.

The four phases

Phase 1: Attack

This is the fast start, usually lasting from one to seven days depending on how much weight you want to lose. You eat only pure protein foods from the list, such as lean beef, chicken and turkey without skin, fish, seafood, eggs, and fat free dairy. You also eat about 1.5 tablespoons of oat bran daily and drink plenty of water. There are no vegetables, fruit or bread. Most of the weight lost in this phase is water and glycogen.

Phase 2: Cruise

In this phase you alternate between days of pure protein and days of protein plus non starchy vegetables, until you reach your target weight. Vegetables allowed include spinach, cucumber, tomatoes, cabbage and green beans. Potatoes, corn and legumes are not allowed. Oat bran continues, about 2 tablespoons a day.

Phase 3: Consolidation

Once you reach your goal weight, you gradually bring back some foods to avoid regaining. The length depends on how much you lost, often described as about ten days for each kilogram. You may add some fruit, two slices of whole grain bread a day, a portion of hard cheese, and one or two meals a week with starchy foods, plus one celebration meal a week. Oat bran rises to about 2.5 tablespoons a day.

Phase 4: Stabilization

This is meant to be permanent. You may eat normally, with three rules: have one pure protein day every week (often Thursday), eat 3 tablespoons of oat bran daily, and walk or be active every day, including taking the stairs.

Does the Dukan diet work?

In the short term, it can produce quick weight loss. This is not surprising. Any plan that removes most carbohydrate and fat, forces you to eat simple foods and increases protein will usually cut calories and drain water stores. The first weeks of the Attack phase can show a rapid drop on the scale.

But there is very little high quality research that follows people for a year or more on this specific plan. Most evidence for high protein diets in general comes from other trials with different designs. What we do know from broader studies is that:

  • Most diets produce similar weight loss when calories are equal.
  • The best diet is the one you can stick to.
  • Fast weight loss is easy to regain if you cannot maintain the method.

What do experts say?

Dietitians have mixed opinions, and many criticise it. Common concerns raised by nutrition professionals and dietetic associations include:

  1. It is extremely restrictive, especially in the first phase, making it hard to follow socially and long term.
  2. It is very low in fibre and in some vitamins, because fruit, vegetables and whole grains are limited or absent early on.
  3. It may cause constipation, bad breath, fatigue, headache and dizziness, which are common on low carbohydrate plans.
  4. It can put extra strain on the kidneys for people with kidney disease, and may increase the risk of kidney stones and gout in susceptible people.
  5. The unlimited eating message can hide the fact that calories still matter.
  6. It is hard to maintain, and regain is common after the plan.

On the plus side, many people like its clear rules, the simplicity and the inclusion of walking and a lifelong maintenance plan. High protein eating is also helpful for fullness and for keeping muscle during weight loss, as we explain in high protein diet for weight loss.

Who should avoid it?

Talk to your doctor first, or avoid this plan, if you:

  1. Have kidney disease, kidney stones, gout or liver disease.
  2. Have heart disease or high blood pressure that needs medicine.
  3. Have diabetes, especially if you take insulin or tablets that lower blood sugar.
  4. Are pregnant or breastfeeding.
  5. Are under 18 or older and frail.
  6. Have a history of eating disorders.

A balanced alternative: Dukan style principles without the extremes

You can borrow the useful parts of the plan, such as a protein focus, simple meals and daily walking, without banning whole food groups.

  1. Eat lean protein at every meal. Chicken, fish, eggs, yogurt and legumes.
  2. Fill half your plate with vegetables. They add volume and fibre.
  3. Keep some smart carbohydrates. Oats, beans and whole grains are filling and good for your gut and heart.
  4. Add healthy fats in measured amounts. Olive oil, nuts and fish.
  5. Walk every day. Aim for 7,000 to 10,000 steps. See how many steps a day to lose weight.
  6. Set a realistic pace. Losing 0.5 to 1 kilogram a week is sustainable.

Our Mediterranean diet for beginners is a well researched pattern with excellent long term results. For a very low carbohydrate approach with a medical background, read the keto diet for beginners.

Pure protein meals that fit the idea

If you still want to try high protein, low fat meals, a few Sports Kitchen recipes show how it can look with full nutrition information:

Notice that these include vegetables, which most nutrition experts would encourage in every meal.

What happens when you stop?

The biggest challenge with any strict plan is the day after. When you return to normal eating, water and glycogen come back, and the scale rises quickly. This is normal, but it can be discouraging. To avoid it:

  1. Return to normal food gradually.
  2. Keep your protein high.
  3. Keep exercising, especially strength training.
  4. Weigh yourself weekly and track a rolling average. Read how to track weight loss progress beyond the scale.
  5. Learn to eat without fear. Read building a long term relationship with food.

Do not fall for diet myths

Many diets rely on promises like "lose 5 kilograms in a week" or "eat unlimited food and still lose weight". Remember that sustainable weight loss comes from a calorie deficit you can hold for months, with enough protein and movement. See nutrition myths that won't die and the truth about detox diets.

Frequently asked questions

How much weight can I lose in the Attack phase? Many people report 1 to 3 kilograms, mostly water. It is not all fat.

Is oat bran important? It provides fibre, which helps digestion and fullness. You can also get fibre from vegetables, legumes and whole grains.

Can I follow Dukan if I exercise? Light activity is fine. Intense training may feel difficult during the very low carbohydrate Attack phase.

Is Dukan the same as keto? No. Both are low carbohydrate, but Dukan is low in fat and high in protein, while keto is high in fat.

Is the Dukan diet safe long term? There is little long term research. Most experts prefer balanced, flexible approaches.

This article is general information and not medical advice. Speak with your doctor or a registered dietitian before starting any restrictive diet.

How FiTPLATE gives you a plan that is balanced and safe

You can reach your goal without extreme rules, and FiTPLATE helps you do it.

  • A calorie and protein target for you. FiTPLATE calculates a safe daily target from your body, goal and activity level and never goes below a safe calorie floor.
  • A daily log that makes every meal count. Search, scan barcodes or use quick add, and see your calories, protein, carbs and fat live.
  • Meals from your fridge. Take a photo of what you have, set a protein goal and ask for a meal. Or browse high protein dishes in the Sports Kitchen.
  • Weekly check ins. Log your weight and FiTPLATE suggests changes only when your trend calls for them.
  • Meal reminders and a weekly shopping list to keep you on track.

Start your free trial and build a plan you can keep

References

  • Morton RW et al. A systematic review, meta analysis and meta regression of the effect of protein supplementation on resistance training induced gains in muscle mass and strength in healthy adults. British Journal of Sports Medicine, 2018.
  • Wycherley TP et al. Effects of energy restricted high protein, low fat compared with standard protein, low fat diets: a meta analysis of randomized controlled trials. American Journal of Clinical Nutrition, 2012.
  • Devries MC et al. Changes in kidney function do not differ between healthy adults consuming higher versus lower protein diets: a systematic review and meta analysis. Journal of Nutrition, 2018.