Michael Pollan is getting a lot of attention for his recent book, In Defense of Food: An Eater's Manifesto. (tag phrase: "Eat food. Not too much. Mostly plants.")
I buy used books, so I'm reading his previous book, The Omnivore’s Dilemma: A Natural History of Four Meals (2006).
I'm about 3/4 of the way through the book and it's been a fascinating tour of our industrial agricultural food system, our industrial organic food system, a beyond organic / local food system, and in the final pages a local hunter/gatherer food system.
His complete message is nuanced and best read and interpreted for one's self, but one obvious take home message is that there are glaring problems with application of industrial techniques to food production. A brief summary of the guiding philosophy one could take home from the book is here.
The introduction and first chapter of The Omnivore's Dilemma (PDF)
Other writing by Michael Pollan.