The 17 Day Diet - Good or Bad?

I've been reading a lot about this new 17 day diet.  You can read about the program and even read the first chapter of the book here.  The very basic premise here is that you cut your calories to 1,200 a day eating natural, unprocessed foods.  They have cycles of 17 days so that your body doesn't get used to one diet and some cycles introduce new foods to spice things up.  When you get to your goal weight, the maintenance plan is to stay on the diet during the week and go buck wild on the weekends.  Although buck wild probably isn't really the right phrase.  You could ruin your progress if you binge.  According to the write up on WebMD it is actually a pretty good plan.  Of course they suggest adding more fruit and a multi-vitamin.  So all in all this seems like it could be a viable option for people.  But as always with any diet, read all the material and follow the plan accordingly.