Researchers have taken a step towards documenting the black box that is our metabolism:
Here we describe Recon 2, a community-driven, consensus ‘metabolic reconstruction’, which is the most comprehensive representation of human metabolism that is applicable to computational modeling.
Their model is available at http://humanmetabolism.org/. Here’s a visual map:
Thanks to Asclepius for the pointer. As he says, Simply CICO eh?
Weight Maven is written by Beth Mazur. Beth believes that obesity is more symptom than cause and that the real problem is our Western diet -- especially sugar, refined grains, and industrial oils. Beth writes about nutrition, ancestral health, & food policy. And cats! 
Thanks Beth, any chance we can access a readable version of this?
I don’t know if it’s much more readable, but there’s a large png version here.