I also read the Hacker's Diet, but I went to a doctor-controlled diet, and lost about 34 pounds so far (15 kg), in two months (not 6 months).

It's fairly similar to what John advocates actually :) - it's eating WAY less, slower, and mostly vegetables (the main thing about this diet was that the clinic provides the food so you can't overeat).

And yes, I was very hungry at first, what I did was drink lots of soup (the instant-soup type, there are some "light" versions by Knorr over here), and yoghurt (also "light").

I didn't eliminate sodas, I replaced them with diet versions (doctor said they were OK for diet purposes).

PD: as another poster said, NO SUGARS, no flour (that means no bread, etc.. . that part is hard!) and no butter and other dairies except for yoghurt.