Designed for a target weight loss of 10-17 pounds in a week, it was apparently developed in 1985 for employees of General Motors and originally intended for their exclusive use.
Whatever the exact origin, it's well worth doing for a week - subject, of course, to checking with your doctor, which you should do before starting any diet.
It's a bit wacky, but the test we were privy to resulted in an 11 pound loss in a week. Rather than taking time and space on your computer now, you can go to Google, enter 'General Motors Diet' and the first one up gives you the full diet details.