I have read a lot into this as well, there is another "diet" that falls into this type of calorie restriction as well. It's called "The Alternate Day Diet" It was also called Dr Johnsons up day down day diet. I have a friend named Marie who is 70 something, and lost all her excess weight using that plan. She is a friend i have on Sparkpeople.com
This is my friends spark page, her name is "Bug" real name marie. She is a great gal, and swears by the alternate day plan, she also does periodic Water Fasts of one or two days a week.