In reality, the rules of this diet are disappointingly mundane. Take 100-400 calories of flavourless food, such as light (not extra virgin) olive oil, a couple of times per day, in a 'flavourless window' each day (wait at least an hour after eating, and then wait an hour until eating again...). Other than that, you eat normally. That's it. Simplez.
The diet is based on the fundamental principle of a "set point" - the weight which your body wants to be. When your weight is below the set point, appetite increases, and when it's below the set point, appetite decreases (I think that this may be based on some prehistoric principle that enabled people to eat more at times of plenty, to store fat for leaner times). The creator of this diet is Seth Roberts, a Professor of Psychology at the University of California. He believes that by eating certain foods, you can raise or lower your set point, essentially fooling your body into losing weight. Foods that have a strong flavour-calorie relationship (such as a big mac) can raise the set point, whereas bland foods which are slowly digested (like light olive oil) can lower the set point. The idea is that you break the association between taste and calories.
There's no specific calorie restriction, although the idea is that there will be self-regulation, as appetite decreases, which produces weightloss.
A word of caution, I found this online:
"I’m not sure if this diet is a hoax or not. It’s possible it is a social psychology experiment. Maybe Dr. Roberts had a bet with someone that “anyone can write a popular diet book if they just use the formula".There's a lot of long words and some graphs at sethroberts.net if you want to decide for yourself.
What I can tell you: the olive oil tastes grim, but I haven't eaten for two hours... My start weight hovers around an annoying 10 stone, but this weeks diet should be a breeze compared to Dukan...