We'd avoid the Cabbage Soup fad diet, which has been around forever and which desperate dieters still try with alarming regularity. While cabbage itself is a fine vegetable and a healthy part of any diet, having it (with a few other veggies in the soup) to excess, to the exclusion of other foods is simply not healthy or sustainable. A menu of all carbs with effectively no protein or fat simply won't work. The diet is simply too low in complex carbs, protein, vitamins, and minerals. By pushing the body into starvation mode, it will likely lower metabolism and actually encourage the body to hold onto fat reserves, losing water and muscle instead. You're likely to feel tired on this diet, as your body simply won't have the energy it needs to function normally.
The diet spread by word of mouth for years until 1997, when Margaret Danbrot published a book on it. The best current source on this diet is her revised New Cabbage Soup Diet book. Again, we disagree with the claims the book makes--that you'll lose "up to 10 pounds in 7 days." Much of any weight loss will be water of course, and much of the rest will be the accumulated contents of your colon, as there will be little solid material ingested on the diet. This may be a bit off-putting, but it's true, as this resembles a detox/colon-cleansing diet in many ways. This book's version does at least allow a meager 8 ounces of skim milk or yogurt so there's some protein, but again, we don't consider this a healthy diet.
We have to admit there are some positives to sticking to this diet--it is certainly simple--you can make up all the soup at once at the start of the week, and you can eat as much as you like.
If you're feeling desperate (or sadistically curious) and simply must give this diet a whirl, we'd definitely suggest limiting it to a week (if you can last that long), by which time you will never want to see another cabbage again. You could treat it as a jump-start diet, something to get a bit of initial loss before you transition into a healthy, more long-term diet.
There are other diets in the Cabbage Soup Diet vein, extreme plans which are often meant to serve as a detox diet and be followed for only a week, they include: the Baby Food Diet, Grapefruit Diet, Juice Fast Diet, Maple Syrup Diet, and Scarsdale Diet--none are recommended.
Menu: This is the simplest menu of all the diets we review--cabbage soup for breakfast, lunch, and dinner. Recipes for the cabbage soup vary by source, but most are simple, based on cabbage, onions, celery, and the like. You're allowed to drink as much as you can stomach.
Prices: You can pick up the latest in-depth book version of this diet on Amazon for around ~$7. Prices for the menu vary, though you will need quite a bit of fresh food to put together all the soup. At least you can make it up in big batches all at once at the start of the week, and cabbage soup freezes well, so when you fall off the wagon, you can salvage the remainder ... if you can stomach it again after the experience.