Body Opus is Dan Duchaine.

I have read it and followed it for about 3 weeks but for my bodyweight the carb loadings were too much I was sick as a dog after my first one and could barely get it all in.

This is not an Atkins diet, though it does use Ketosis phases, it is a really good read and goes into everything in great detail.

Plus I like Dan's style he has no hype, no BS, he's not selling anything and he done it all - he experimented on himself and understands the drugs, etc too.