If you can stick to it, I do recommend the fat fast from my recent personal experience. I lost 11 pounds or so in two weeks, and while much of it may have been water, and i did not get my bodyfat percent checked, I am inclined to believe it was mostly fat, as my jeans are now about two inches looser, my strength, which was temporarily down a bit during the diet, is back up to where I started, and I look ripped as hell–for some reason my arms and chest seemed to get the most ripped, but now my abs are a lot more defined.
I could only stick to the diet for two weeks, but I am glad I did it, and, the first day I quit, I ate all the protein and fat I wanted, and got a little bloated, but then after that I have gone to a moderate diet, and that is easy now, whereas before the fat fast, I was addicted to taco bell and mcdonalds. With regard to your question as to how to do the fat fast, I ate a little sugar free metamucil or lettuce each day, and I had 4 0r 5 whey shakes and 4 or 5 teasons of flax oil each day. The second day was hell for me, and I felt like I was dying, and driving seemed extremely dangerous, and each day after that I would go through like 30 min. of craving for food here or there, but it was not that bad. I also trained pretty hard during the diet, which I think eventually lead to my temporary strength loss, and encouraged me to quit the diet. Also, on the day after I quit the diet, I took a lot of ibeproffen in addition to pork skins, and I swelled up with a huge ammount of water and was worried for a while–seriously, I stepped onto a scale and was 8 pounds heavier than 12 hoours earlier, and my stomach was protruding, and walking felt cool as my feet and ankles were so swollen it was like walking on pads. But it was water and it went away after a day.