New York magazine dubbed it "the diet to end all diets" in a recent cover story. It got a full page in the New York Times Science section and the Wall Street Journal said it "may help you live a longer life." The "it" in question is calorie restriction, a diet that promises to tack years on to your life. Still under scrutiny from scientists, CR is far from being the next South Beach or Atkins, but editors are keeping a watchful eye.

CR, which is more a lifestyle than a diet, is about lowering caloric intake. (Studies have shown that mice and chimps placed on a very low-calorie regimen live longer.) In the New York article, calorie restricters weighed lettuce leaves and were described as being ghostly thin. Brian Delaney, head of the CR Society, said CR is "a set of principles that can be applied in radically different ways." He added that "the New York piece portrayed not just a rigid version [of CR], but also kind of a bizarre one."

Co-author with Lisa Walford of Marlowe & Company's 2005 The Longevity Diet, Delaney is one of the few people to have published a book on the topic with a mainstream house. And Marlowe is one of the few publishers doing CR books. In addition to Longevity Diet, the house has published Lisa Walford's The Anti-Aging Plan (1994) and Roy Walford's Beyond The 120-Year Diet. (The late Roy Walford is known as the "father of CR"; his The 120-Year Diet was released by S&S in 1986. Lisa Walford is his daughter.)

Matthew Lore, v-p and publisher of Marlowe, said these books are solid backlist titles; he reports that Beyond The 120-Year Diet and Anti-Aging Plan have each sold "well over 30,000 copies," and Longevity Diet has sold 20,000. Although Lore admitted that CR is practiced by only a small group—Lisa Walford estimated that 25,000 Americans practice a dedicated CR lifestyle—the diet's fountain of youth promises could tap into one of the most attractive demographics for publishers: baby boomers.

But where the media goes, book buyers may not follow. "This is not a simple lifestyle, like Weight Watchers or Jenny Craig," said Sydney Miner, an editor at S&S. "To reach a level of popularity like some of the other trends, it has to be doable and sustainable."

Judith McCarthy, publisher of consumer books at McGraw-Hill, said she suggested a CR book at an editorial meetings two years ago. Although the decision was made then not to publish, she is "definitely keeping an eye" on CR and what's being written about it. Still, she echoed Miner's hesitation: "We tend to look for things that don't feel so deprivation-laden... even the name sounds so hard, tough and not fun."