When Michael Pollan refers to the "Western diet" he's talking about a dietary choice that consists of in taking large amounts of red meat, sugary desserts, high-fat foods, and refined grains Pollan believes that Americans need to escape from the Western diet because he thinks it is the cause of many chronic diseases.
Pollan responds to the "they say" by reassuring his audience that at the end of the day these scientific views are only mere explanations. The answer, he says, is quite simple, all people need to do is stop partaking in this dietary choice. Pollan's objection to these scientific views is that they are only meant to benefit fast food industries and medical companies, not eaters. Fast food industries use these reports to tinker with