Paul and Meredith started practicing CR 12 years ago at the recommendation of Paul's doctor, who is a CRONie himself. Today, Paul eats 1,900 calories and, at 5-foot-11, weighs 137 pounds. Meredith eats 1,600 and, at 5-foot-4, weighs 110. That's as low as they allow their weight to go, they told me, to stave off rapid bone loss.

Paul and Meredith have converted their parents, several other family members, and half of Paul's employees to CR. (They have no children.) They're writing a book: The CR Way. And, like members of a cult, they expressed suspicion of those on the outside—such as spouses who don't practice CR and find its effects disturbing. When I brought up Dean's psychological symptoms, Paul said: "In my observation, you know what would cure him? If his wife did it, too."