The Dukan Diet

You have probably come across its name, on a magazine cover or in a conversation with friends. The Dukan Diet owes its fame to Dr Pierre Dukan, a French doctor who popularised it in the 2000s. Its principle can be summed up in one sentence: lots of protein, very few carbs, and a journey split into four phases. Current evidence suggests it can help with short-term weight loss, but it remains restrictive and is not suitable for everyone.

How it works in four stages

The attack phase relies almost exclusively on protein: meat, fish, eggs, low-fat dairy. Its length depends on the stated goal. Then comes the cruise phase, where you alternate pure-protein days with days that include allowed vegetables. The consolidation phase gradually reintroduces other foods, with two celebratory meals a week according to the method. Finally, stabilisation requires one pure-protein day a week and rules to keep up long term.

Woman with mixed heritage standing near a window, hand resting on the waistband of her trousers — A pair of trousers that fits just right — a simple sign of the first few kilos lost

What you risk

A diet very high in protein and very low in fibre can cause fatigue, constipation, bad breath, headaches or nutrient deficiencies. In vulnerable people, it can also put strain on the kidneys. Current evidence also suggests that very restrictive diets encourage weight regain after you stop. In France, ANSES warned as early as 2010 about the risks of unbalanced weight-loss practices.

Lentils, wholemeal bread, prunes and almonds arranged on a light linen cloth — Fibre — the big missing piece in a very high-protein diet

This diet is not suitable if you have kidney disease, diabetes, an eating disorder, are pregnant or are a teenager. If any of these apply to you, do not start it on your own.

Before changing your diet, speak to your GP or a registered dietitian. Support can help adjust your plan, spot deficiencies and avoid harmful extremes.

In practice

For sustainable weight loss, official guidance favours gradual loss, a varied diet and regular physical activity. You do not need to ban all starchy foods or count every gram. Start with simple steps: cook more, drink water, get enough sleep, walk every day. The Dukan Diet may help some people structure their meals, but it does not address the causes of excess weight. The real challenge is sticking with it over time without putting your health to one side.

Young woman walking briskly along a tree-lined path early in the morning — Moving every day: the simplest habit to keep up long term

Budget

The cost of support varies by practitioner and region. In the UK, seeing a GP is free on the NHS. A private registered dietitian typically charges around £50 to £100 per session. A private GP appointment often costs £50 to £100. A private nutritionist or endocrinologist may charge around £60 to £150 for a consultation, with follow-ups often costing less. NHS referrals to dietitians are free, but waiting times vary. Private consultations are not usually covered by the NHS, though some health insurance policies may reimburse them. Prices vary depending on location and whether you see someone privately or through the NHS. You can find support at your GP surgery, in a hospital clinic or via online consultations.