Pollan begins with an exploration of the food-production system from which the vast majority of American meals are derived. This industrial food chain is largely based on corn, whether it is eaten directly, fed to livestock, or processed into chemicals such as xanthan gum, often in the form of high-fructose corn syrup, and ethanol. Pollan discusses how the corn plant came to dominate the American diet through a combination of biological, cultural, and political factors. He visits George Naylor's corn farm in Iowa to learn more about those factors. He mentions the fact that human cultivation of corn has greatly benefited the plant, and that corn has come to depend on humans for its survival. He argues that the "cob and husk arrangement... renders the plant utterly dependent for its survival on an animal in possession of the opposable thumb needed to remove the husk, separate the seeds, and plant them" (26-27). The role of petroleum in the cultivation and transportation of the American food supply is also discussed.
A fast food meal is used to illustrate the end result of the industrial food chain. Pollan is highly critical of the industrial model of agriculture. He describes how scientific innovations such as the creation of the Haber process to fix nitrogen allowed a widespread simplification of agriculture. He argues that at one time, farmers applied a cultural knowledge to the growth of plants, but that this "intelligence and local knowledge" (220)  has since been removed from their farms and put into the laboratory. He believes that this is a negative development, and that a return to localized agriculture would solve many of the health and environmental problems that he believes are the result of modern agricultural practices.
In addition to visiting Naylor's corn farm in Iowa, Pollan spends time in a feedlot, observing the conditions in which a steer is kept prior to slaughter. He explains that the steer is fed a corn-based diet, which has a detrimental effect on an animal adapted to consume grass. Pollan claims that this unnatural diet detracts from the nutritional value of the meat produced from the steer, not to mention the quality of life of the animal. Additionally, Pollan contends that the excessive use of antibiotics in these feedlots has led to drug resistant microbes, neither of which would have become issues if cows were allowed to live under more natural conditions (78).
The following section delves into the principles of organic farming and their various implementations in modern America. Pollan shows that, while organic food has grown in popularity, its producers have adopted many of the methods of industrial agriculture, losing sight of the organic movement's anti-industrial roots. A meal prepared from ingredients purchased at Whole Foods Market represents this food chain at the table. In his discussion of the foods he purchases from Whole Foods Market, Pollan comments on the