If this post seems a bit out of the blue, it's because it was written a while ago and I'm currently going through the draft bin attempting to publish up some of that mostly done stuff.
First, it is important to note that there are actually three versions of The Perfect Health Diet book (perhaps four, I am unsure if the Kindle version was updated from the first print version, but I'll refer to the self-published Kindle version as v.2). I mention this because the first ebook was published in 2010 as was the self-published paperback and the latest version was completed late in 2012. While there are some minor changes, the core of the basis for the PHD has not changed much, if at all and if there were major changes I would expect Paul to highlight them in his various appearances. So, in v.1 and v.2 the rationale behind the macronutrient content was put forth in a very straightforward manner in a section entitled:
Four Reasons to Believe in a 20-65-15 Macronutrient Ratio (Carb-Fat-Protein)
- This was the composition of the Paleolithic Diet
- This is the composition of breast milk (adjusted for adult brain size)
- This is the composition of the human body - Eat what you are.
- Omnivorous animals prefer to eat this diet
