It has certainly worked for me in the past. A couple of years ago I stumbled upon this way of life pretty much by accident - I went a good year eating from around 1-6 and the weight not only fell off (gradually), but within a couple of months I had more energy and was generally feeling more optimistic than I ever have in my entire life. Moreover, this way of life is doable - pretty much pain free (you learn to enjoy the sensation of an empty stomach before 'breakfast'.). And you will have lots of energy.
I since moved countries and fell into the old 3 meals a day (plus nibbling, junk etc. etc.) and then weight crept back on. I am now 20 kilos overweight.
I recently did some google searching and discovered that this was actually a recognised diet - printed of the booklet on the Fast5 website and have joined the yahoo support group: