After breakfast? I would include breakfast as well. My energy levels after a breakfast of bacon and eggs is far steadier than after any breakfast cereals, toast, muffins, pastries, etc. Avoiding any large carb intake (post workout _possibly_ excepted) is key to steady energy levels.

For a more rational book, try Robb Wolf's "The Paleo Solution", which also has an extensive chapter on sleep and cortisol management.