The Dukan diet is a low-carbohydrate (carb), high-protein diet. There’s no limit to how much you can eat during the plan’s four phases, provided you stick to the rules of the plan. During phase one, you’re on a strict lean protein diet. This is based on a list of 72 reasonably low-fat protein-rich foods, such as chicken, turkey, eggs, fish and fat-free dairy. This is for an average of five days to achieve quick weight loss. Carbs are off limits, except for a small amount of oat bran.
Unlike the Atkins diet, Dukan’s phase one bans vegetables and seriously restricts fat. The next three phases of the plan see the gradual introduction of some fruit, veg and carbs, and eventually all foods. The aim is gradual weight loss of up to 2lb a week and to promote long-term weight management. There’s no time limit to the final phase, which involves having a protein-only day once a week and taking regular exercise.
You can lose weight very quickly, which can be motivating. It’s a very strict and prescriptive diet, which some people like. It’s easy to follow, and you don’t need to weigh food or count calories. Apart from keeping to low-fat, low-salt and high-protein foods, there’s no restriction on how much you can eat during your first two weeks.
At the start of the diet, you may experience side effects such as bad breath, a dry mouth, tiredness, dizziness, insomnia and nausea from cutting out carbs. The lack of whole grains, fruit and veg in the early stages of the diet could cause problems such as constipation.
Rapid weight loss can be motivating, but it is unsustainable and unhealthy. The Dukan diet isn’t nutritionally balanced, which is acknowledged by the fact you need a vitamin supplement and a fibre top-up in the form of oat bran. There’s a danger this type of diet could increase your risk of long-term health problems if you don’t stick to the rules. The diet lacks variety in the initial phases, so there’s a risk you’ll get bored quickly and give up.