I got bored trying to read through that whole diet mess. But the one thing I do agree about (or at least it works better for me) is consistently changing up the workouts.
You can take me through the hardest boot camp availible on a daily basis and I guarantee my body will have adapted to it by the time most people are used to it enough to be able to get through that shit without being out of breath. The bad thing is, when my body adapts, not much more than maintenance happens. This is okay if I'm where I want to be (which is never). Shitty for making major changes (like weight loss over 15#).
From what I did read on that diet, I know I would need a bit more than that to function...and especially to lose weight...if working out that hard. I've been there, done that with as low as 1000 cals a day and it actually impeded my weight/fat loss efforts. Losing weight by starving your body almost always eventually causes rebound fatassedness which is even harder to lose the next time around since more of the weight is fat since your body had to eat some of its muscle while you were trying to subsist on 1000 cals.