I'm doing this "diet" and so far so good. I really think this is something I can do for life, because even though eating just 500 calories is hard, I can eat normally on the other 5 days. It's very early days yet, but so far I have lost 7lbs! I plan to do my "fasts"(calorie restrictions) on Mondays and wednesdays and also do a semi "fast"(1000) on Sundays.
My first fast day was horrid. I sapced the 500 calories throughout the day and stoped eating at 6pm- big mistake! For me there is nothing worse than going to bed on an empty stomach, so on wednesday I saved all my calories for after 6pm. Another side effect I noticed is being much more emotional on fast days. This might have something to do with the fact I am an emotional eater and so I couldn't have my pacifier so to speak, so I had no choice but to deal with my emotions.
For me, the greatest thing about this diet is that I although I don't necessarily have to cut anything out of my diet, it makes me more cognisant of what I am actually putting in my mouth. I look forward to food and it takes me a lot longer to eat than it used to. On my non fasting days I have not binged at all. On Tueday I consumed around 2090 calories and yesterday I had around 1600! So for me fasting one day does not equal a binge the next.