More Reason to Crazy-Spice

Spices are good for you, I blogged, because they are high in antioxidants. A new study, done in Singapore with elderly subjects, supports this conclusion. It found that curry-eaters do better than others on a mental test. The abstract:

Curcumin, from the curry spice turmeric, has been shown to possess potent antioxidant and antiinflammatory properties and to reduce ß-amyloid and plaque burden in experimental studies, but epidemiologic evidence is lacking. The authors investigated the association between usual curry consumption level and cognitive function in elderly Asians. In a population-based cohort (n = 1,010) of nondemented elderly Asian subjects aged 60-93 years in 2003, the authors compared Mini-Mental State Examination (MMSE) scores for three categories of regular curry consumption, taking into account known sociodemographic, health, and behavioral correlates of MMSE performance. Those who consumed curry “occasionally” and “often or very often” had significantly better MMSE scores than did subjects who “never or rarely” consumed curry. The authors reported tentative evidence of better cognitive performance from curry consumption in nondemented elderly Asians, which should be confirmed in future studies.

Tze-Pin Ng, Peak-Chiang Chiam, Theresa Lee, Hong-Choon Chua, Leslie Lim and Ee-Heok Kua. Curry Consumption and Cognitive Function in the Elderly. American Journal of Epidemiology 2006 164(9):898-906

How Well Does the Shangri-La Diet Work? (part 1: breakdown by starting weight)

The most basic question about the Shangri-La Diet is how well it works. As the host of The Amazing Race might say, there are many ways to answer this question, each with their own pros and cons. Thanks to Rey Arbolay, we can answer this question in a new way: by looking at the data in the Post Your Tracking Data Here section of the Shangri-La Diet forums, where more than 80 people have posted.

The goal of SLD, of course, is weight loss. The problem with just plotting pounds lost as a function of time on SLD is that a loss of 10 pounds is quite different to someone who starts at 120 pounds and someone who starts at 300 pounds. To deal with this I have divided the results by starting weight. In the graphs below, the ranges of weights were chosen so that there would be roughly the same number of people in each graph.

Starting weight makes a big difference — at least, between the two extremes. Many of the people who aren’t losing very fast are in the lowest quartile. There are still a few outliers — people at the higher starting weights who are losing slowly if at all — but not many.

The next step is to do an analysis that estimates the effect of starting weight and somehow removes it. It might be better to divide people by BMI rather than starting weight, and maybe the y axis can be improved.

Brain Food (part 6: a little more progress)

I did two balance experiments with a warmup of 8 trials. In one, the order of feet (which foot I stood on) was left, then right; in the other, right, then left. In both experiments I did much better (i.e., balanced longer) on my right foot than my left foot, ps < 0.001. This surprised me; I had never heard of such an asymmetry. The difference was so large that the platform size (0.75 inch) good for the left foot was too easy for the right foot. To make things as simple and easy as possible I decided to stop testing both feet and to only measure balancing on my right foot (and to use a 0.5-inch platform to make it more difficult and avoid a ceiling effect). I tested my balance (a) in silence and (b) listening to a book. The results were similar so I decided the standard condition will be listening to something. I want to make my balance test fast and pleasant. I came across several promising related facts: 1. On the Shangri-La Diet (SLD) forums, spacehoppa said she felt “solid on [her] feet” — which may mean her balance has improved. If so, the improved balance that I noticed may be widely true. She also said “my mind feels clearer,” another effect I noticed from omega-3’s, and more reason to think omega-3 improve brain function.

2. On the SLD forums, porkypine wrote, “I have a very strong reaction to the 1500 mg of OmegaBrite that I have begun taking in the morning. . . . During the day, I am not just happier, but actually chipper, which is not a normal state for me. I have wondered if I am getting too much Omega-3.” This supports one of the assumptions behind my upcoming tests of the effects of omega-3 on balance: the effects of omega-3 on the brain happen quickly. It also highlights an advantage of measuring balance rather than something else, such as mood — namely, it is reasonable to assume that the better your balance, the better your brain is working. As this quote shows, the mapping between mood and goodness of functioning is not so clear.

3. In a book about neurology (Defending the Cavewoman by Harold Klawans), including Creutzfeldt-Jacob disease, I read: “A [Fore] woman in late pregnancy who was unable to walk easily across a narrow tree trunk bridging a gorge knew from that change in her balance that she had kuru and that she would die of it. The physicians examined her and thought she was normal, but in less than one year, she was dead.” This shows that balance is an especially sensitive measure of brain function, at least under demanding conditions. It’s relatively easy to notice worse balance.

Balance is also much easier to quantify than many other measures of brain function, such as mental clarity.

Brain Food (part 5: a little progress)

I’ve been doing small experiments on my balance to learn what affects it. Most research using new tools follows a progression. Step 1: you learn what people already knew. Step 2: you find new information that isn’t very interesting. Step 3: you find interesting new information. Earlier I found that I could balance on one foot longer on a wider platform — Step 1.

Now Step 2. I’ve done a few experiments comparing different footwear (sandals, shoes, barefoot). In each experiment I ran several conditions, each consisting of 12 trials standing on my left foot followed by 12 trials standing on my right foot. These trials had gaps of seconds between them. Different conditions (different footwear) were separated by at least 10 minutes and usually more.

The right-foot average was always more than the left-foot average. You can see examples of this in my earlier results. I doubt that the right foot/leg is actually better than the left so this suggests there is a substantial warmup effect, as there is in most tasks.

To make measurements more precise, it would help to have a warmup period before collecting the main, more stable data. How long should it be? The graph below shows data from many of the conditions I have run arranged by trial number, with a lowess summary line.

The y axis is in log seconds, not seconds; I used a log transform to make the distribution of the data more symmetrical. The maximum time was 30 seconds. (Log(30) = 3.4.) If I kept my balance for 30 seconds, I stopped, and recorded the result as 30 seconds.

The graph shows an early warmup period that lasts 6-8 trials long, followed by a slow improvement that lasts at least 24 trials. Here is something new and not very interesting: details about the warmup effect.

Brain Food (part 2)

Do omega-3 fatty acids improve brain function? I blogged earlier that switching from olive oil (low omega-3) to walnut oil (high omega-3) and flaxseed-oil capsules (very high omega-3) caused my sleep, my balance, and maybe my mood to improve. If you are interested in duplicating what I did, here are details:

Supplies. I take (a) 2 tablespoons/day walnut oil (Spectrum Organic refined). Store locator at will help you locate this. Total 240 calories. (b) 10 1000-mg capsules/day of flaxseed oil (Longs cold-pressed softgels). Longs drugstore house brand, which is only available at Longs drugstores. Total 100 calories. I store both in the refrigerator but they are in stores at room temperature (reasonably enough, since walnut trees and flax plants live at room temperature). Procedure. I take both between meals. I divide the walnut oil into 2 doses of 1 T each that I take at least several hours apart. I take 80% of this stuff after noon. I spread the flaxseed capsules out throughout the day, take about 3 at a time. But read on for more helpful info — you may not want to start with exact duplication.

With the new oils, my sleep was consistently and unusually good for about two weeks, making it was clear that the improvement was caused by the new oils (or more precisely, the difference between the new oils and the oil they replaced). Less clear was what aspect of the dietary change made the difference. I switched to walnut oil and flaxseed oil because they were high in omega-3; but they differ from olive oil in other ways as well.

It would be great to know more — both to maximize the effect on myself and to help others get the effect. The wonderful thing about finding a food component that improves sleep — if that isn’t wonderful enough — is that it is likely to improve the brain in all sorts of other ways, too. (In contrast to my previous sleep research on the effects of non-food-components, such as standing and breakfast, where the improvements were probably specific to sleep.) The data about omega-3 support this view: A wide range of improvements in mental function have been observed. Assuming omega-3 causes a single change in the brain, that change causes (a) a reduced rate of Alzheimer’s, (b) less depression, and (c) better sleep — so it is likely to be widespread in the brain.

Since my earlier post, I’ve gathered some new and helpful data.

First, a Shangri-La-Diet forum poll found that most people who used olive oil for the diet had better sleep (10 out of 12), even though olive oil is relatively low in omega-3. Can even a small amount of omega-3 improve sleep? (Small compared to my current dose. SLD dieters consume large amounts of olive oil compared to everyone else.) Or is some other component of olive oil causing the change?

Second, after reading my earlier post, Catherine Johnson remembered that “I realize that I started sleeping miserably when I stopped taking Omega 3s.”
I trust that sort of thing. I had had a similar now-I-understand experience. After figuring out that lots of standing improves sleep, I remembered that several years earlier I had sleep very well the night after visiting lots of art studios during an Open Studios day. At the time I had guessed that it was all the art-inspired thinking that had caused my much-better-than-average sleep. But it was also a day with much more standing than usual.

Third, I reduced my flaxseed-oil intake by half: I took 5 capsules instead of 10. To my great surprise, I woke feeling as I felt with the olive oil. I hadn’t felt that way in weeks. The next day I went back to 10 capsules and again woke up feeling great. Obviously this strengthens the plausibility of omega-3 –> better sleep because the crucial ingredient is apparently in high quantities in the flaxseed oil capsules.

The stunning thing, the reason I was so surprised, is this: I didn’t expect the flaxseed change to make a difference so quickly. When someone ate a zero-folate diet to learn about the effects of folate, it took months for the effects to become clear. Although I had noticed the sleep improvement caused by the new oils the very next morning, I had assumed that was because I was quite deficient — like someone with scurvy noticing fast improvement with Vitamin C. Someone who is not Vitamin-C-deficient will have to go without Vitamin C for months before scurvy occurs. I had expected to wait weeks before seeing sleep degradation.

If you read about why omega-3 is important, you will read endlessly that our brains are made of it — the fraction of our brain that is omega-3 fatty acids is 10% (Wikipedia?), 60% (a Whole Foods employee), whatever. That is what I had assumed: that omega-3 is a structural element of our brains. Which is no doubt true. I have never heard that it is a metabolic element of our brains. Cars are “made of” carburetors, fan belts, computers, tires, and the like (structual elements); they “run on” gasoline and electricity (metabolic elements). Structural elements are parts. Metabolic elements are fuel. Failure to replace a perfectly good carburetor or other structual element will eventually cause trouble, but it may be several years. Failure to replace gasoline or electricity will cause trouble much sooner. Thus my little experiment suggested that omega-3 was a metabolic element.

If an effect can be turned on and off quickly it is much easier to study than if it takes weeks or months to turn on or off. Upcoming attractions: How I am studying it.

Blogger Alert

My publisher will send a review copy of The Shangri-La Diet to the first 25 bloggers who are interested in reviewing it. Please send an email with the URL of your blog and your mailing address to:

with the subject line “Review Copy”.

Spices: A New Kind of Vitamin?

For Shangri-La dieters who randomly spice their food, the current issue of the American Journal of Clinical Nutrition (July 2006) has very good news. Spices are a better source of antioxidants than any other food group, according to a survey of popular American foods.

There are many reasons to think antioxidants are beneficial. Oxidative damage, which antioxidants reduce or prevent, seems to play a role in many major diseases, including heart disease. Yet large trials in which people were given a few antioxidants, such as alpha-tocopherol and beta-carotene, did not find health benefits. Maybe the reason for these failures is that you need a suite of antioxidants; maybe antioxidants, “which cooperate in an integrated manner in plant cells [to reduce oxidative damage], also cooperate in animal cells,” the authors write. “A network of antioxidants with different chemical properties may be needed for proper protection against oxidative damage.” A very plausible idea.

To test this idea, it would help to know the antioxidant content of everyday foods. This is what the researchers tried to find out. They used a chemical assay to measure the total antioxidant content of 1113 popular American foods, chosen based on a careful national survey.

Here are the top ten foods by antioxidant content (per gram): cloves, oregano, ginger, cinnamon, tumeric, walnuts, basil, mustard, curry powder, pecans. Here are the next ten: baking chocolate, parsley, molasses, pepper, artichokes, dark chocolate, blackberries, whole-grain cereal, cranberries, chocolate pudding mix. Chocolate is also high in antioxidants — more good news. Red wine was #30. (White wine was low.)

Lowest on the list were animal products. “In general, plant and plant products in the diet have a much higher antioxidant content than do animal products,” the authors wrote. Oils, such as canola oil and olive oil, were higher than animal products, but less than other plant products. Cooking (heating) increased the antioxidant activity of plant foods such as carrots, tomatoes, and spinach.

The end of the paper describes evidence that higher intake of antioxidants is associated with lower risks of stomach cancer and lung cancer.

Could vitamins plus fiber plus spices provide most of the health benefits of fruits and vegetables? It is entirely possible. If so, it would be a major nutritional advance. Spices would be a new kind of vitamin. Good nutrition would include at least one heavily-spiced meal per day.

Berkeley Public Library Watch:The Shangri-La Diet, 3 holds on 5 copies. The Omnivore’s Dilemma by Michael Pollan, 128 holds on 29 copies. Website Watch: Distinct hosts served at, latest 24-hour period: 832. One month ago: 539. Distinct hosts served is close to the number of different visitors.

Brain Food

On the Shangri-la diet forums, many dieters have reported better sleep. (“Woke up feeling like I could fight tigers. Have not felt this way since 2003. . . . I would stay on this method just for the sleep benefits,” wrote bekel.) To learn how widespread this was, I did a poll. Forty-two people answered. Two-thirds of them reported better sleep (half “much better” sleep, half “slightly better” sleep). Only one-tenth of them reported worse sleep (all “slightly worse”, none “much worse”). Almost all of them were doing SLD with oil, implying that the improvement was due to a few tablespoons of oil per day.

This was exciting. A small, almost trivial dietary change seemed to be causing a big important improvement. I had switched from sugar water to ELOO about three years ago and had not noticed any sleep improvement. Perhaps this was because the improvement is due to omega-3 fatty acids, of which ELOO has much less than other oils. And because I ate a few servings of fatty fish (such as salmon) per week, I might have been less omega-3 deficient than most. Thinking about the poll results, I remembered I had slept unusually well about a week or so earlier. At roughly the same time, for reasons I can’t remember, I had taken six or seven flax-oil capsules. This vague correlation was curious. It raised the possibility that a large dose of omega-3’s might have a noticeable effect.

To test this idea, I made two changes: (a) I started drinking 2 tablespoons/day of walnut oil. Walnut oil (12% omega-3) is a much better source than olive oil (1%) or canola oil (7%). (b) I started taking 10 flax-oil capsules/day (= 100 calories/day). Flax oil (58% omega-3) is an especially good source. (I drank Spectrum refined walnut oil, which has little flavor, and I mixed it with water to reduce its flavor. Another walnut oil I have tried, International Collection, has a strong walnut flavor.)

It seems to make a difference. Three differences, actually: (a) Better sleep. I wake up more clear-headed, less foggy. (b) Better mood. My overall mood is slightly better, in a hard-to-describe way. (c) Better balance. For the last two years, I have often put on and taken off my shoe-laced shoes while standing; even after two years of practice there was plenty of room for improvement. Suddenly this became much easier. All three changes began the day after the dietary change (about a week ago) and since then have not only persisted but if anything have gotten stronger.

Do these bits of data — survey and self-experimentation — mean anything? I think so. Consider other facts:

1. SLD dieters using oil report many other improvements that seem unrelated to less hunger or weight loss. Most of them fall into three groups: (a) Skin. Everyone reports softer skin. In addition, spacehoppa’s eczema and keratosis pilaris (permanent gooseflesh) got much better “It’s like I’m correcting a major nutritional deficiency,” she wrote. Shrinkingbean found her eczema improved after only 10 days. CarolS‘s acne has gotten much better. (2) Mood. Easier to give up smoking and coffee. More libido. (3) Stiffness. “I have been a person who gets stiff when sitting too long, ever since I was in high school. . . . Sitting in one place for 15 minutes would cause me to stand up from the chair like a 90 year old. . . . It just dawned on me that that is no longer true!!!!” wrote Ann. Two others noticed similar effects.

2. Several studies of patients with mood disorders have found their symptoms improved when they were given fish oil (high in omega-3) compared to a placebo group. A review of these and similar studies notes that “the marine-based omega-3 fatty acids primarily consist of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and appear to be highly biologically active. In contrast, those from plants (flaxseed, walnuts, and canola oil) are usually in the form of the parent omega-3 fatty acid, alpha-linolenic acid. Although dietary alpha-linolenic acid can be endogenously converted to EPA and DHA . . . research suggests that this occurs inefficiently to only 10%-15%.”

3. Several surveys of the elderly have found an association between (a) reduced risk of Alzheimer’s disease and less cognitive decline and (b) greater fish consumption. At the other end of life, omega-3 fatty acids are necessary for proper development of our brains, a point made here. The effect of an essential nutrient is likely to be clearest in those who are most vulnerable (such as babies, the elderly, and the mentally ill).

What makes the overall idea — we need more omega-3 than most of us get — even more plausible is that a pre-existing theory makes sense of these facts. That theory is the aquatic-ape hypothesis, the idea that humans became big-brained primates while living near water and eating lots of fish. In 2005, Sir David Attenborough, whose nature documentaries I love, made a fascinating radio show about this theory. The end of the show provides new supporting data that I find especially persuasive.

If our brains grew big while eating lots of fish, it makes perfect sense that they would work better when we eat lots of fish. More precisely, too little fish (or too little of fish’s crucial nutrients) should harm the portions of our body that evolved during that period (shaped to work well on a high-fish diet) much more than older portions (shaped to work well on a low-fish diet). The improvements associated with omega-3 fatty acids — reduction of cognitive decline in the elderly, mood improvements in the mentally ill — fit that prediction well. So does the conclusion of a recent meta-analysis that omega-3 does not clearly reduce heart disease or cancer.

And so do the benefits of oil (presumably from omega-3) suggested by the SLD forums and my self-experimentation. Sleep: My earlier self-experimentation suggested that sleep is influenced by morning conversations and amount of standing, implying considerable differences between our sleep and the sleep of other primates. Skin: Human skin has fat attached, like marine mammals but unlike the skin of other primates. (This fact inspired Alistar Hardy to think of the aquatic ape hypothesis.) In addition, we have much less hair than other primates. Stiffness when standing up and balance on one foot: Unlike other primates, we are bipedal.

How to measure my sense of balance? . . .

Winery Alert

I wince when I hear someone say that he or she couldn’t possibly drink olive oil. “Gross!” is how it is usually put. I’m sorry to hear something culturally learned treated as a timeless truth. So I was pleased when my friend Aaron Blaisdell reminded me that wineries are beginning to have olive oil tastings. What is learned can be unlearned. The more accepted olive oil drinking becomes, the less I will have to hear “gross!” when it is suggested.

Here is a NY Times article about these tastings. If anyone doing olive oil tastings reads this, I hope you will post about your event in the announcements section of the SLD forums. I suspect many forum readers are becoming oil connoisseurs.

A Little Bit of Paris

Yesterday was an little milestone. The SLD was so easy and fun that I did it too much. I couldn’t eat my one meal of the day. Part of my brain said: You really should eat something, if anything you’re too thin. Like a parent to a child. But I didn’t. (And woke up this morning not hungry at all.) Was I testing the power of the SLD and went a little too far? No: it was an accident. Which is why it is interesting.

This has never happened before. I discovered the basic idea of the SLD and got down to my current weight six years ago. Since then I have eaten one meal per day, including any number of meals I could have easily skipped. The thing is: I didn’t skip them. The part of my brain that said eat even when I wasn’t hungry was powerful enough to overcome my lack of hunger. Yesterday, for the first time, it wasn’t. It reminded me of being unable to eat in Paris, which led to my discovery of the SLD.

After six years, why now? Because of the SLD forums. In two months they have injected enough new ideas into the diet (e.g., take oil with water, oil improves sleep, crazy spicing is worth pursuing) to make it too much fun. (For me.) Hard to believe, I agree. Here is what I ate yesterday:

1. Early in the morning, a cup of tea (unfamiliar flavor) with one sugar cube. I’ve done this a thousand times. 15 calories.

2. A few sticks of gum. I’ve done this thousands of time. 0 calories.

3. Around 11 am I drank some walnut oil (Spectrum). I bought it a few days ago because of a forum post about its benefits. I drank 2 tablespoons of it with water — testing my friend Carl Willat’s suggestion that he drew from the forums. I don’t have trouble drinking oil but the oil/water mixture is even easier, a curious texture. This was slightly different than usual: I have been drinking 1-2 tablespoons oil/day for the last 3 years but (a) I have always drunk 1 T in the morning and 1 T later in the day, sometimes forgetting the second dose and (b) I have tried many different oils but not walnut oil because it has some flavor. The water seems to eliminate or greatly reduce the flavor. 240 calories. So far: 255 calories.

4. More gum. Thousands of times. 0 calories.

5. A few small pieces of excellent dark chocolate. Thousands of times. 50 calories? So far: 305 calories.

6. Small amounts of several cheeses. Thousands of times. 100 calories? So far: 405 calories.

7. Half a bottle (8 oz., whole bottle is 16 oz.) of Healing Springs Raw Watermelon Kambucha. An associated website ( is non-functional. I almost never drink strange soft drinks because I’m afraid they will ruin my appetite, as they did in Paris six years ago. But in Paris I drank about two per day. This time I drank half a bottle — surely too little to matter, I thought. Such an interesting flavor, honey-sweetened. No indication of how many calories. 60 calories? So far: 465 calories.

8. Protein drink. Curious about tasteless protein drinks, I tried to follow a recipe from Sean Curley. My drink contained 1 tablespoon each of 3 different protein powders. To improve the taste I added one sugar cube, a package of Splenda, and some random spice blends. 75 calories. So far: 540 calories

9. 10 flax-oil capsules. A week or so ago I slept unusually well and somewhere around that time I had taken about 6 flax-oil capsules. Forum discussion led me to think the flax oil might be responsible. I took 10 capsules to see if I could repeat the experience. 100 calories. So far: 640 calories

10. Chai ice blend. To make swallowing the flax-oil capsules enjoyable I made a chai drink to wash them down. I blended together sugar-free chai mix, 4 oz. half-and-half, water, and ice. I’d had about 10 cups of this mix before. To make the flavor more interesting, I added a couple shakes of two random spice blends. 212 calories. So far: 852 calories.

At this point I decided I didn’t want dinner and took a long walk instead.

11. Two sugar-free chocolate-chip cookies. New-product sample left at my house. 100 calories. So far: 952 calories.

12. Two Emer’gen-C (vitamin) packets mixed with 3 tablespoons half-and-half. Makes a lovely mousse-like concoction. Vaguely-familiar flavor. 90 calories. So far: 1042 calories.

Total flavorless calories: 340. Total unfamiliar-flavor calories: 347. Whereas normal values would be roughly 240 flavorless calories and <100 unfamiliar-flavor calories. So I had at least doubled my usual intake of these hunger-suppressing foods. Not because I was trying to lose weight, though, but because of forum discussions, because I found combinations of random spice blends intriguing, and because I wondered if flax oil caused better sleep. Not a long-term healthy diet but v v filling and v v easy.

I woke up the next day having slept unusually well. For me, it was an unusual form of good sleep. Many times I have slept extremely well after standing 9 or 10 hours but in these cases I woke up feeling scrubbed clean of tiredness. In this case, however, I didn’t feel scrubbed clean of tiredness (and I hadn’t stood 9 or 10 hours) but my brain felt very clear when I awoke. I’d been drinking oil for years — this wasn’t produced by my usual oil intake. If it was cause and effect (oil caused better sleep), something found more in walnut oil and/or flax oil than in canola oil or ELOO or safflower oil or grapeseed oil (oils I had had many times in the past) was responsible.

Meal Skipping: Good or Bad?

Many people find that the Shangri-La diet makes it easy to skip meals. It is natural to ask: How does meal skipping affect overall health? Having eaten one meal per day for the last six years, let’s just say I care about the answer.

For more than half a century it has been clear that calorie restriction is a powerful way to increase the lifespan of rats and at least a few other species. An experiment with monkeys seems to be headed for the same result: calorie restriction increases lifespan.

Calorie restriction is a complex treatment. Calorie-restricted rats eat less, they lose weight, they may eat less often, they eat less protein, they eat less carbohydrate, and so on. Which of these changes cause the health benefits? A researcher at the National Institute of Aging named Mark Mattson has been asking this question. He and his co-workers have discovered that the benefits of calorie restriction can be achieved by eating less frequently, even when there is little or no weight loss. The implication is that skipping meals, if anything, is likely to be beneficial.

One study, published in 2003, compared four groups of mice. One group (ad lib) got all the food they wanted every day. Another group (calorie restriction) got 60% of the amount of food that the first group got. A third group (intermittent fed) got all the food it wanted but only every other day. A fourth group got the same overall amount of food as the intermittent-fed group, but without a one-day “fast” between feedings. After 20 weeks, the calorie-restriction mice weighed about half what the ad-lib mice weighed; the other two groups weighed about 90% of what the ad-lib mice weighed. The most interesting measure was what happened when kainic acid (which kills neurons) was injected into the brains of the mice. The measure was how many neurons survive. The results were not easy to completely sum up but they did show that intermittent feeding was more protective than ad lib feeding, and at least as protective as calorie restriction. In other research from Mattson’s lab, intermittent feeding has been found to be healthier than ad lib feeding in other ways — for example, a rat study found protection against heart-attack damage. A review article by Mattson concluded that “both caloric (energy) restriction (CR) and reduced meal frequency/intermittent fasting can suppress the development of various diseases and can increase life span in rodents.”

What about humans? In January I was contacted by Dr. James Johnson, Dr. Donald Laub, and Sujit John, who had been studying the effect of intermittent feeding on humans — starting with themselves. Johnson had tried to lose weight via an on-day-off-day diet: One day you eat normally, the next you eat 20% of what you would usually eat. I think he based this diet on Mattson’s results. Eating only every other day — the usual regime in Mattson’s experiments — was just too hard but Johnson found that eating a percentage on the order of 20-30% of usual intake on the off days was just bearable and did produce weight loss. Johnson found that not only did it produce weight loss, it had many other beneficial effects, such as an improvement in asthma symptoms. He first noticed these improvements when he tried the diet himself (he wanted to lose weight); later he saw similar improvements when his friends did the diet, the same path I followed with SLD. Johnson, Laub, and John have just published an article in Medical Hypotheses about their ideas. They were interested in my weight-loss ideas as a way of making the on-and-off regime more bearable — to reduce the hunger involved. “The oil and sugar water seem to work well,” Dr. Laub wrote me recently.

Here is the abstract of their Medical Hypotheses paper:

Restricting caloric intake to 60-70% of normal adult weight maintenance requirement prolongs lifespan 30-50% and confers near perfect health across a broad range of species. Every other day feeding produces similar effects in rodents, and profound beneficial physiologic changes have been demonstrated in the absence of weight loss in ob/ob mice. Since May 2003 we have experimented with alternate day calorie restriction, one day consuming 20-50% of estimated daily caloric requirement and the next day ad lib eating, and have observed health benefits starting in as little as 2 weeks, including insulin resistance, asthma, seasonal allergies, infectious diseases of viral, bacterial and fungal origin (viral URI, recurrent bacterial tonsillitis, chronic sinusitis, periodontal disease), autoimmune disorder (rheumatoid arthritis), osteoarthritis, symptoms due to CNS inflammatory lesions (Tourette’s, Meniere’s) cardiac arrhythmias (PVCs, atrial fibrillation), menopause related hot flashes. We hypothesize that other many conditions would be delayed, prevented or improved, including Alzheimer’s, Parkinson’s, multiple sclerosis, brain injury due to thrombotic stroke atherosclerosis, NIDDM, congestive heart failure.
Our hypothesis is supported by an article from 1957 in the Spanish medical literature which due to a translation error has been construed by several authors to be the only existing example of calorie restriction with good nutrition. We contend for reasons cited that there was no reduction in calories overall, but that the subjects were eating, on alternate days, either 900 calories or 2300 calories, averaging 1600, and that body weight was maintained. Thus they consumed either 56% or 144% of daily caloric requirement. The subjects were in a residence for old people, and all were in perfect health and over 65. Over three years, there were 6 deaths among 60 study subjects and 13 deaths among 60 ad lib-fed controls, non-significant difference. Study subjects were in hospital 123 days, controls 219, highly significant difference. We believe widespread use of this pattern of eating could impact influenza epidemics and other communicable diseases by improving resistance to infection. In addition to the health effects, this pattern of eating has proven to be a good method of weight control, and we are continuing to study the process in conjunction with the NIH.

Huh. My question is: Am I skipping enough meals?

My First Reading

Yesterday I did my first bookstore “reading,” at Stacey’s Bookstore in San Francisco. Having seen several hundred such events on Book TV (C-Span 2), it was quite a thrill. Like one’s first day as professional baseball player. It wasn’t hard to fill 20 minutes; professors have been known to take longer than that to clear their throat. And I had a 20-year story to tell. I didn’t read anything from The Shangri-La Diet but I did quote liberally from Ann Hendricks’ repositioned blog now devoted to reporting “happenings in the Shangri-La diet e-world” in order to summarize the 6000-odd posts in the forums. All the seats were full (all 20 of them), if I remember correctly, and there were plenty of questions.

On the way to the reading area I saw a book about Jane Jacobs that I hadn’t known existed: Jane Jacobs: Urban Visionary by Alice Alexiou. says it has not yet been released but there it was. After my talk, I wanted to buy it. Unfortunately the store had just one copy and although it had been on display since Jacobs’s death six weeks ago (she died the day my book was published) during my talk that copy was sold. When it rains, it pours.

Berkeley Public Library Watch: The Shangri-La Diet, 1 hold on 5 copies. The Omnivore’s Dilemma by Michael Pollan, 133 holds on 7 copies. Website Watch: Distinct hosts served at, latest 24-hour period: 613. One week ago: 755.

Will It Live?

Mr. Tanguay, my beloved seventh-grade science teacher, did an unforgettable demonstration one day. “Class,” he announced, “we’re going to see if we can create life.” Into a graduated cylinder he poured a lot of water. Because the human body is 95% water. He added a few more chemicals — salt, a few others. Finally he added a mystery ingredient. The mixture began to swirl. (Maybe the mystery ingredient was vanilla extract.) “It’s coming alive!” said Mr. Tanguay. Then the swirling stopped, as I knew it would. It was a brilliant demonstration not because it taught us biology (it didn’t) but because it showed that Mr. Tanguay had a nice sense of humor. I actually looked forward to his class.

Watching The Shangri-La Diet progress, I thought of that demonstration. I saw swirling — would there be life? Books, or the ideas within them, live and die. Word of mouth is primitive book life. It resembles replication if listeners buy the book or repeat what they’ve heard. Life is more than replication, of course; books can produce descendants (sequels), mutations that fill a new ecological niche (e.g., a teaching guide for Freakonomics), and new goods and services (such as movies).

At a micro level, the SLD forum activity — more than 4000 posts — seemed to me a kind of pre-life. Not because of the success — many diets work for short time, and how representative are those posting? — but because of the emotion (“after the very first day, I finally for once in my life had real hope”) and the inventiveness and fruitful observation. New and better ways to drink oil, tests of whey protein and random (“crazy”) spicing, the observation that quitting smoking has become easier are examples. No other diet has had this much user improvement, as far as I know. However, the forums involve a miniscule number of people (about 500 members) compared to the size of the world in which a diet book would live (hundreds of millions of overweight people).

I wondered if there were larger signs of impending life. Right now SLD is #29 at but does this tell the whole story? Or is it different from other books with similar sales? I started to look at this about two weeks ago. From the top 100 best-selling books at and, I sampled 20 (10 from amazon, 10 from barnesandnoble) whose titles were unique enough to use as search terms. On May 20 I found the number of Google results for each title. On May 28 I redid this calculation. Because a book, to live, must “grow,” at least in the beginning, I looked at the change from May 20 to May 28. Below is the change in Google results as a function of days since publication (log scale).
google change vs days

SLD stands out, although not as much as The World Is Flat. After I did this analysis it occurred to me that blog mentions might be a good measure to examine because they resemble word of mouth. Was SLD blogged about more than books with similar sales? Although it would have been better to measure the change from May 20 to May 28, all I had were the values for May 28 so I computed blog mentions per day since publication.
blog mentions vs days

Again, SLD appears at least somewhat special. The World Is Flat stands out in this analysis as well and so does Beautiful Lies, which I know nothing about.

We already know that The World Is Flat is an unusual book by virtue of being a best seller for more than a year. It is encouraging that SLD has World-Is-Flat tendencies. And watch out for Beautiful Lies.

Berkeley Public Library Watch:The Shangri-La Diet, 2 holds on 5 copies. The Omnivore’s Dilemma by Michael Pollan, 131 holds on 7 copies. Website Watch: Distinct hosts served at, latest 24-hour period: 1190. One week ago: 1611. Distinct hosts served is close to the number of different visitors.

Ford vs. Roberts

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 – 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.

The Ecology of New Ideas

A curious feature of the Shangri-La diet is how much its spread has been helped by things that did not exist a few years ago.

First, open access. My article with the data and ideas behind the diet was published in an “open-access” journal and stored in an “electronic repository.” Thus anyone with Internet access could read the article. The repository now has about 12,000 articles; mine was Number 117.

Second, blogs. Interest in this article was greatly amplified by blogs. My friend Andrew Gelman blogged about it. His post was read by Alex Tabarrok, who wrote about it at Marginal Revolution. His post was read by Stephen Dubner and led to a Freakonomics column in the New York Times — a great way to get book publishers’ attention. After the column (sadly eclipsed by Hurricane Katrina), a few blogs focussed on the diet and helped me weave a fuller view of its effects into the book I soon got a contract to write. When the book was published, quite a few bloggers had already heard about its main idea, which rendered its very strange concept slightly less strange, i.e., more acceptable. Now it is being discussed and tried in several blogs (see Blogroll)

Third, forums — the Shangri-La diet forums at At a talk about user interfaces a few years ago, I heard a famous designer say that new devices went through three stages of use: (a) hobbyist; (b) expert; and (c) mass market. Departments of electrical engineering, he said, were good at providing products for the first two stages, but were poor at making mass-market products. As far as the Shangri-La diet is concerned, this is what the forums have done so well: made the diet acceptable to almost anyone. They have made the oil easier to drink, answered all sorts of common questions, and provided reassurance (it may sound crazy but it works), expert advice, and support.

Recently I heard Yochai Benkler, a professor at Yale Law School, speak on “The wealth of networks: How social production transforms markets and freedom” at an MIT symposium. This example supports his general point that new network-related products (such as open access) are empowering the little guy — the little guy here being me, who never got a large grant to support this research.

Why did these three new things (open access, blogs, and forums) all start at roughly the same time? Of course all of them were made possible by the growth of the Internet but so were a billion other things that haven’t yet come to pass. I have been working on a theory of human evolution that says language evolved because single words helped people trade. I think the growth of the Internet has been caused by the modern version of just that — better connection of buyer and seller. But open access, blogs, and forums have nothing to do with commerce. I think all three arose from another basic human tendency: a desire to share our enthusiasms. During the early days of electronic discussion groups (called bulletin boards), I was greatly disappointed that not one was devoted to Spy magazine. Why did we evolve this basic tendency? Because it led to the beginning of science — the intertwined growth of knowledge. So it makes quite a bit of sense that these three new things together acted in a kind of scientific way, bringing an effective weight-loss method out of darkness.

Berkeley Public Library Watch:The Shangri-La Diet, 4 holds on 5 copies. The Omnivore’s Dilemma by Michael Pollan, 116 holds on 7 copies. Website Watch: Distinct hosts served at, latest 24-hour period: 1494. One week ago: 888. Distinct hosts served is close to the number of different visitors.

Scenes From the Life of a Best-Selling Author

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 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, latest 24-hour period: 4667. One week ago: 874. Distinct hosts served is close to the number of different visitors.

Is the Spread of an Idea Like an Epidemic?

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 after an interview on the Dennis Prager show, the 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 Here are graphs of the total number of posts, topics, and members (upper graph) and the rates of their growth (lower graph). forum growth as of 5/16 forum growth rate as of 5/16

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, latest 24-hour period: 948. One week ago: 875. Distinct hosts served is close to the number of different visitors.

Week of Long Walks

“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 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, — have already begun to pay off. The book is #31 at — 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, 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, latest 24-hour period: 883. One week ago: 452. Distinct hosts served is close to the number of different visitors.