Level of Effort: Medium
Prepping your food shouldn't be a problem, and you don't need exotic ingredients. But you will be pretty restricted in what you can eat at the start of the diet.
Level of limitations: Eating mainly protein and oat bran can get tiresome. The Academy of Nutrition and Dietetics suggests that meals include fruits, whole grains, and healthy fats, which the Dukan Diet doesn’t emphasize.
Cooking and shopping: It's easy to plan, shop for, and prepare meals on this diet.
Packaged foods or meals? None required.
In-person meetings? No.
Exercise: A daily 20-minute walk is essential to the plan.
Does It Allow for Dietary Restrictions or Preferences?
Vegetarian or vegan: This diet is based on eating a lot of lean meat, poultry, fish, shellfish, fat-free dairy, and eggs. Seitan, tempeh, and tofu are the veggie protein options available -- beans, nuts, and lentils aren't on the diet's list of allowed foods. On days when all you eat is protein (no fruits or veggies allowed), things can get boring quickly if you don’t eat meat.
Low-fat diet: If you’re already following a low-fat regimen or have a heart condition that requires eating ultra-low-fat foods, this diet might fit like a glove, since the allowed foods -- mainly protein, veggies, and fruit -- are lean, low-fat, or no-fat.
Gluten-free: The earlier phases of the diet may work for a gluten-free diet, but as the rules relax, it's not strictly gluten-free. If you're trying to avoid gluten completely, make it a habit to read food labels carefully.
What Else You Should Know
Costs: None beyond your shopping, unless you sign up for online coaching, which is optional and costs $29.95 per month.
Support: There is a strong community aspect to this plan. The official web site offers sample recipes, inspirational success stories from real men and women (not just superstars), and coaches who help guide dieters through each phase.