Alex Chernavsky has kindly given me several years of weight data he collected by weighing himself daily. He read about the Shangri-La Diet in 2005 and several years later decided to try it. The graph above shows what happened: Starting at 222 pounds (BMI = 32), over 11 months he lost 31 pounds, reaching a BMI of 27. Since then — while continuing the diet — his weight has increased at roughly the same rate it was increasing before he started the diet.

He started by drinking olive oil and sugar water, switched to olive oil alone, and then, finally, to flaxseed oil alone of which he drinks 3.5 tablespoons/day (= 420 calories/day). He does not clip his nose shut when he drinks it but he washes his mouth with water afterwards. More about his method here.

Almost all weight-control experts would say these results are impossible: 1. Alex lost weight because he ate more fat. Fat is fattening say most nutrition experts. 2. Atkins dieters, who don’t say that, think the secret of weight loss is to reduce carbohydrate. Alex didn’t do that (and eats plenty of carbohydrate). 3. He didn’t restrict what he ate in any way. 4. He didn’t change how much he exercised.

Quite apart from how it contradicts mainstream beliefs, including Atkins, the data are remarkable because the change was so simple, small, and sustainable, the weight loss so large, the rebound so minimal, and data period so long.

An ordinary clinical trial has obvious advantages over such one-person data, such as more subjects and more data per subject. Less obvious are the advantages of this sort of data over clinical trials:

1. Long pre-diet baseline. Clinical trials never have this. It allows one to judge if weight increase post-diet, often called “regain”, is due to the weight loss or other factors. In this case the rising pre-diet baseline shows that other factors are causing slow weight gain over time.

2. Motivation. In a clinical trial, the motivations of the researchers and the subjects are different. The researchers want to measure the effect of an intervention; the subjects want to lose weight. If paid, they may want to make money. The difference in motivations causes problems. How closely the subjects obey the researchers and how truthful they are is usually hard to know. This data does not have that clash of motivations and incentive to lie.

3. Realism — what methodologists call ecological validity. These data, unlike clinical trial data, come from the situation to which everyone wants to generalize: people trying a diet by themselves at home without professional support or guidance.

4. Level of detail available. You (the reader) have access to something resembling raw data. In clinical trial reports, the data available is heavily filtered (e.g., shortened, simplified) and the nature of the filtering rarely described. For example, you rarely learn in any detail what the subjects ate. With this sort of data, but not clinical trial data, you can get a better sense of whether the results are likely to apply to you.

David Mandel, CEO of Alliance United Insurance Company, asks a very reasonable question:

Despite all the success stories [on the Internet] regarding the Shangri-La Diet, and the mainstream media stories in 2006 after the book publication, the diet never picked up and seems almost unknown today.

Whether this is right or wrong depends on expectations. In December, SLD got a great push from being on the website of Tim Ferriss’s Four Hour Body under the attractive title “Alternative to Dieting”. Tim’s book was published in December and registrations to the SLD forums jumped dramatically. Yet even before that, forum traffic was growing. Traffic of course grew when the SLD book came out, later shrank, and now — surprisingly — is growing again. My interpretation is that the initial growth was caused by mainstream publicity and blogs. The current growth is caused by word of mouth.

If I google “Shangri-La Diet” I get about 800,000 hits, a decent amount. “Sonoma Diet” — the book came out the same time as mine — gets 200,000 hits. “Eat Right For Your [Blood] Type” and “Eat Right 4 Your Type” get a combined 150,000 hits. That book was a huge hit when it came out in 1997. The usual pattern is Google hits go down, but SLD hits have gone up over the years.

On the other hand, given that my book contained a new theory of weight control that made about 100 times more sense than the usual ideas and led to counter-intuitive new ways to lose weight that actually worked and that obesity is often considered the world’s #1 health problem — yeah, it is “almost unknown” compared to what one might have expected.

I was wondering if you had any insight as to why it did not go viral, if nothing more from word of mouth from success stories sharing with everyone who will listen to their excitement. It seems all but impossible to me that something this simple, and universally successful which can benefit the masses has managed to not go mainstream in all these years. I am utterly baffled, and assumed there must be a big downside, but all my searching online has revealed nothing but the success stories and initial feedback, mostly from 2006 and 2007, and little since. I am just overwhelmed with curiously as to how this did not become the norm for everyone.

When my agent circulated the proposal for the book, one editor regretfully declined to bid on it because she said the book was “15 years ahead of its time.” Perhaps she was just being nice, but when people tried the diet, and it worked, they wouldn’t tell other people because the diet sounded crazy. Which means it really was far ahead of its time. Good Morning America filmed me for a short Freakonomics-related segment and they played it for laughs: crazy professor.

So that’s my explanation for why it has spread more slowly than one might have expected: fear of ridicule.