Dr. John Ford, a professor at the UCLA medical school, recently posted a criticism of me. Here is my reply.

An obvious problem with Dr. Ford’s critique is lack of evidence. Dr. Ford seems to be saying that The Shangri-La Diet is dangerous but on its face this is absurd. My book suggests that people consume vegetable oils or sugar water. Billions of people already consume these substances in amounts larger than what I recommend. Compared to the drugs that Dr. Ford prescribes every day, they are extremely safe and well-studied. If Dr. Ford is implying that these foods have dangers that he knows about but the rest of us do not, he should be explicit about it: Say what the hidden dangers are, and provide evidence for his claims.

Other problems are less obvious:

First, Dr. Ford has ignored facts that do not support his conclusions. If you search the Internet for people who are trying my weight-loss ideas, you will find many for whom it is working, often very well, and only a few for whom it has failed (harmlessly). Dr. Ford says nothing about this.

Second, factual mistakes. (1) “If Roberts were truly interested in investigating his approach, he should have subjected it to . . . peer review” – implying that I did not. In fact, my Behavioral and Brain Sciences article, which contained my weight-loss theory and support for my weight-loss methods, was peer-reviewed. So was a related article in Chance, which I told Dr. Ford about by email while he was writing his critique. Two is not zero. (2) He says I “present[ed] a highly speculative idea as proven science.” I did not. If he reads my book, he will see that I present a theory, a weight-loss method based on that theory, and promising early results. (3) He says my Behavioral and Brain Sciences paper is “not about validating his hypothesis or conclusions [but] a speculative commentary on the use of self-experimentation.” Actually, it is a long empirical article with a great deal of data – to call it “commentary” is misleading. The evidence in that article supports the theory of weight control on which my diet is based because the theory helped me discover new and surprising ways of losing weight. (4) He claims that self-experimentation is not “accepted methodology.” In fact, the 2005 Nobel Prize in Medicine was awarded for work on ulcers in which self-experimentation played a key role. Awarding someone a Nobel Prize constitutes acceptance of their methodology. As does publication in an oft-cited peer-reviewed journal.

Finally, Dr. Ford is a medical school professor. For a long time, medical school researchers have contributed no useful ideas to our understanding of how the average person can lose weight. At best, they have tested ideas that others have come up with. Could Dr. Ford’s rigid methodological beliefs have a downside? At UC San Francisco, my local medical school, the last time I looked at their online curriculum, about five years ago, medical students were being told to tell patients that weight loss is a matter of calories in versus calories out, therefore eat less, exercise more. Such advice was popular among doctors in the 1950s. It was no better advice then than it is today; it is based on a seriously-incomplete understanding of weight control. If that were my track record — failure for more than 50 years — I would be more open to new approaches.

I agree with Dr. Ford that my weight-loss ideas are not “proven science” and that “seasoned experts” (including medical school professors) may help the rest of us, including me, evaluate them. But I also believe strongly that non-experts can help the rest of us evaluate them. This is why I consider the Shangri-La Diet forums at sethroberts.net – full of non-expert views and observations — to be very important. Dr. Ford and I probably differ here. I suspect he considers these forums useless, or nearly so, for what he calls “scientific” or “clinical” purposes. Time will tell which of us is correct.

I think of it as the bestseller no one has heard of. The Shangri-La Diet is on a NY Times bestseller list. And now is #11 at amazon.com. Really. I am not making this up. Nevertheless . . .

A few days ago I was scheduled for a radio interview by phone from my apartment but at the appointed time no one called. I reached the host. “You’ve written a book?” he asked. Yes, it’s called The Shangri-La Diet, I said. He hadn’t heard of it.

Yesterday I ran into two of my former students. They asked how I was doing. “A book I wrote has just been published,” I said. They were surprised. I told them the title. They hadn’t heard of it. They did remember I was interested in weight control.

Yesterday I went to the bookstore closest to where I live, a very nice independent bookstore. I offered to sign any copies of my book they might have. The woman behind the counter hadn’t heard of it. She looked it up on the computer, found that they didn’t have any copies. You might want to carry it, it’s on the New York Times best-seller list, I said. “Can you come in tomorrow?” the woman asked. “Talk to Nick, he’ll be here tomorrow.”

Berkeley Public Library Watch: The Shangri-La Diet, 4 holds on 5 copies. The Omnivore’s Dilemma by Michael Pollan, 110 holds on 7 copies. Website Watch: Distinct hosts served at sethroberts.net, latest 24-hour period: 4667. One week ago: 874. Distinct hosts served is close to the number of different visitors.

I watched a TV movie last week about a bird-flu pandemic. Starts in China, whole neighborhoods closed off, food runs out, Penn Station giant hospital, millions of deaths, vaccine, baby on the way, ambiguous ending. Not bad, but not good, either. My mind kept drifting to the spread of The Shangri-La Diet.

It is like a contagious disease in the sense that it can be spread person-to-person: Person A reads the book, tries its weight-loss methods, loses weight or at least appetite, tells Person B about it, Person B reads the book, and so on. It is unlike a contagious disease in the sense that it can be spread by media — newspaper article, radio interview, etc. After spiking to #2 on amazon.com after an interview on the Dennis Prager show, the amazon.com rank has drifted down to about #100.

A contagious disease spreads faster and slower: faster when people are close together (subway), slower when they are apart (sleeping). But with a weight-loss idea the variations of rate of transmission are much larger. At one extreme (slow), someone tries it and then three weeks later someone else notices her weight loss and asks about its source and (if I’m lucky) decides to try it — one person “infected” in three weeks. At the other extreme (fast) is something on national TV, where hundreds of thousands of people become “infected” in minutes.

To get some idea of how the idea is spreading, I have been tracking the growth of the forums at sethroberts.net. Here are graphs of the total number of posts, topics, and members (upper graph) and the rates of their growth (lower graph).

There has been little publicity since the Prager interview about two weeks ago, so the recent growth level of about 5% per day presumably reflects word of mouth/blog. The interesting fact is that the growth appears steady at about 5%.

Berkeley Public Library Watch: The Shangri-La Diet, 4 holds on 1 copy. The Omnivore’s Dilemma by Michael Pollan, 110 holds on 7 copies. Website Watch: Distinct hosts served at sethroberts.net, latest 24-hour period: 948. One week ago: 875. Distinct hosts served is close to the number of different visitors.

“How are you doing, after such an exciting week?” my sister asked. Well, I took several long walks — my idea of a big treat. To let the good news wash over me.

Have you heard of Blockbuster, a book by Patricia Marx and Douglas McGrath? Published in 1988? They wrote about the new-author experience in Spy: “Our book came out to whatever is the opposite of great fanfare.” They decided to hire their own publicist. One candidate told them “our book could become known only if we became known. . . . Just one day after Aeschylus died, the publicist said, his play The Suppliant Women, which had been sparsely attended and about to close, was sold out.” Another person told them, “Even if I could get you publicity for the book, which is highly, highly doubtful, what’s the difference? . . . Nothing lasts.” And nothing changes, either, at least in 18 years. Recently I asked Diane Reverand, an editor at St. Martin’s Press, what was the worst thing about being an writer. “How difficult it is to get attention for what you have done,” she replied. “So few books get any attention at all.”

Which is why, when SLD was published (April 25), I was nervous. Two factors loom large in how well a book does: (a) how many people buy the book in the beginning; and (b) how much each buyer recommends it. The first depends more on the author’s fame than anything else; the second depends on the quality of the book. These two factors roughly multiply to determine sales. Big initial audience x poor book = poor sales. Small initial audience x good book = poor sales. People in the movie industry make a similar calculation; they look at (a) size of first-weekend audience and (b) dropoff from Week 1 to Week 2.

In terms of initial exposure, SLD had two strikes against it: I wasn’t famous; and the diet was absurd (”If you had to cook up the ultimate stereotype of a wacky fad diet for use in a comedic novel or film, the Shangri-La Diet would fill the bill,” wrote calorielab.com). For most media, the mental equation is publicize absurdity = lose credibility. On the other hand, Freakonomics authors Levitt and Dubner, my agent (Suzanne Gluck), my publisher (Putnam), my editor (Marian Lizzi), and the book’s two publicists (Stephanie Sorensen and Katie McKee) did a fantastic job of turning just about every possible lever in the book’s favor — so many levers I won’t even start to describe them.

Their efforts — and the support of Ann Hendricks, Stephen Marsh, and, yes, calorielab.com — have already begun to pay off. The book is #31 at amazon.com — and I’m alive. On Wednesday, Dennis Prager, of the Dennis Prager show, interviewed me for an hour. Mr. Prager was extremely positive about the book. He almost never covered diet books, he said, but he was making an exception for this one. To discuss SLD was “a public service.” A public service! He himself was doing the diet, it was working for him, he was amazed how little hunger he felt. He corrected Dubner’s comment on the cover about the book helping “a few million people.” “A few billion” would be more accurate, he said. After that interview, the book soared to #2 at amazon.com, where it stayed for two days. How did you do that? fellow editors asked Marian Lizzi in amazement.

Will those who buy it recommend it? Well, Kathy Sierra, co-author of Head First Java and popular blogger, didn’t buy it but did recommend it — in better-than-glowing terms. She summed up her opinion in an email to Marian, who had sent her a copy: “This book may be nothing less than a miracle.” (Ah, shucks.) It also seems to me that almost all of the forum contributors would recommend the book. And the forums are growing rapidly.

That was the good news last week.

Berkeley Public Library Watch: The Shangri-La Diet, 3 holds on 1 copy. The Omnivore’s Dilemma by Michael Pollan, 96 holds on 7 copies. Website Watch: Distinct hosts served at sethroberts.net, latest 24-hour period: 883. One week ago: 452. Distinct hosts served is close to the number of different visitors.