I don't know much about Ferris, and haven't read the book but I've been a quite devoted life extensionist for a while, researching diets and studies and nutritients relentlessly, and a favorite researcher and blogger of mine is Chris Masterjohn, whose scientific rigor and sobriety is ever unwavering, who wrote a favorable review of 4-hour body.
http://www.cholesterol-and-health.com/Review-Tim-Ferriss-4-H...