There is a review of Michael Pollan's "The Omnivore's Dilemma" at
http://www.michaelpollan.com/press.php?id=68I am sure you can add Nutren to the list along with Jevity, Ensure and VHC. It is mainly dairy (Calcium-Potassium Caseinate) and corn products (Maltodextrin, Corn Syrup Solids and Sugar).
Probably even the dairy cows are fed corn.
Yep, to a large part, PEG or not, if we stick to our traditional diet we're Living on Corn!