The first phase of Dukan's diet - Attack, where you eat pure proteins for the first 4 days, then protein + vegetables on 5th day, then pure protein again on 6h day, and protein + vegetables on 7th day. The Attack phase is for quick and successful weight loss which should be followed by Cruise phase for steady weight loss. It is imperative to take 2 Litres of water a day, and 20 minutes walk will help you lose weight even faster.