What it entails: It's a seven-day detox diet in which you eat a very low-calorie soup that consists of cabbage, onions, tomatoes, onion soup mix and tomato juice. Each day, there are specific foods you can eat in addition to the soup. For example, one day you can eat fruit, one day you can have milk and a banana, one day you can have beef and tomatoes. Who does it:Jaime Pressly and Sarah Michelle Gellar Advantages: You may lose weight, but as with any detox, you are likely to gain the weight back soon after you finish the diet. Disadvantages: You could feel light-headed, weak and irritable. The expert's opinion: "Whenever you go into starvation mode," Hendel says, "your metabolism will slow down because it’s trying to maintain any kind of energy stores you have thinking that the famine could go on for some time. Then you’re in that slow state when you suddenly drop the diet and binge. And it takes some time for your metabolic rate to recalibrate, so you'll gain the weight back more quickly."