Oh I've been doing it for years! As soon as I notice the waistline expanding, or I feel like a bit of 'detox', I try to schedule myself on a week where the fridge isn't too full of nice and/or perishable things, and I have a good mean on sunday night.

Then it's occasional fruit juice in the morning (bit of an energy boost) and coffee only until the friday.

It's a lot easier than it sounds, the 'key' thing is preparation; pick a week were you don't have a lot of 'social' to do, or any heavy physical things planned, and near empty fridge is good; instruction to the family not to decide to cook your favorite meal during the week and so forth.

Otherwise it's as reported; hunger on the first day mostly, then nothing; you get a bit of a metallic taste in the mouth, but tolerable... You get what I only can describe as a 'high' on the third/fourth day.

I lose roughly 1Kg a /day/ with that method, so if you do it once every quarter or so, that's largely enough to make up for some the odd chrismas/party/easter and so on :-)