The book is dense, bringing together a huge number of scientific studies that date back to the beginning of the the 20th century. His goal seems to be to overwhelm the reader with evidence that many of the assumptions about diet, obesity and disease are wrong. He isn’t content to give you one or two examples of studies that suggest that carbohydrates are the primary factor behind obesity, diabetes, heart disease, cancer and a range of other modern illnesses that were rare before the 20th century. He piles it on, determined to make sure that someone can’t read his book and dismiss it as “some fad diet book.” If you say he is wrong, you better bring your citations with you.

I’ve enjoyed the ride, but I wonder how many readers get bogged down and don’t finish it, or don’t care so much about the reams of evidence that Taubes has compiled and want to skip to his conclusions. One passage near the end that jumped out at me as something that people need to know:

By the mid-1960s, four facts had been established beyond reasonable doubt: (1) carbohydrates are singularly responsible for prompting insulin secretion; (2) insulin is singularly responsible for inducing fat accumulation; (3) dietary carbohydrates are required for excess fat accumulation; and (4) both Type 2 diabetics and the obese have abnormally elevated levels of circulating insulin and a “greatly exaggerated” insulin response to carbohydrates in the diet

He has done a good job. His book is why I’m trying a low carb diet. I’m taking a gamble, even going directly against my doctor’s orders to lower my already low cholesterol, hoping that would help my ailing gallbladder (after all, my first three gallbladder attacks all came after large restaurant meals full of carbs).

I’m going to give it a try. I’ll see how I feel in a month. Will I feel better? Will I lose the 20 pounds I have left to lose? Will I have another gallbladder attack? I’ll let you know.

UPDATE: I blogged too soon. I’m now in the epilogue and he has 7 main points he was trying to communicate in the book. I’ll add them here later.

Female participants consumed two differently flavored desserts. Each was presented three times on separate days. One was formulated with a high-energy content (1882 kJ) and the other with a low-energy content (226 kJ). After training, we found little evidence for learned satiation. However, we did observe flavor-preference learning. Specifically, participants acquired a greater liking and desire-to-eat the dessert flavor that was paired with a higher energy density during training.*

* Emphasis added by me. Also, I don’t mean to suggest that the authors of this study are proponents of SLD or even that they are aware of it, only that the author of SLD cites flavor calorie association studies as early inspirations for his own ideas.

In other words,

• The more we eat high-energy content foods (HECF), the more we will crave such foods.
• The more we eat foods with the same flavor, the more we will crave those foods, as long as those foods are also dense sources of calories.

It doesn’t seem like much of a leap that eating the same foods over and over might contribute to weight gain, provided those foods had a strong, consistent flavor and dense calories. Junk food, fast food, sugary bevarages and heavily processed foods all seem to fit into this theory nicely. Seth Roberts, the author of the Shangri-la Diet, calls these foods ditto foods. I think most people would accept the idea that foods which are dense in calories are fattening. What might be surprising is how important strong, consistent flavors are.

What are some other things that might be true?

• If we eat strongly flavored, dense energy foods, the increased food cravings may make us eat more food in general, not just eat more of the specific food with the association.
• Conversely, if our diet mostly consists of bland foods or foods which are lightly flavored, perhaps we would eat less food overall.

These don’t seem like great leaps of logic. What is surprising is the idea that if you consume flavorless calories in addition to your regular meals, you become satiated sooner, eat less overall and lose weight. Intuitively, it may be hard to wrap our heads around: By adding calories to our diet we consume less overall, as long as those calories are flavorless. But that is exactly how I went from 220 pounds to 180 pounds in about 6 months, by consuming a few hundred calories a day via flavorless oils.

I changed little else in my routine. I didn’t exercise that much. I didn’t starve myself. I did try to avoid ditto foods like McDonalds, but I had already mostly cut those foods out of my diet, SLD just gave me one more reason to avoid those foods.

Lastly, I don’t claim to understand all this. I’m not sure that the oil led to my weight loss. Certainly there could have been another more important factor that I’m not seeing. Perhaps it was mostly a plecebo effect. I hope there are some scientific studies done to determine if this actually works. It should be easy to test in rat trials and I think it should be easy to test in human trials too. For now it seems like an interesting hunch that is amassing a lot of anecdotal evidence.

I am probably too easily swayed by these kinds of books, ones which set out to prove that conventional wisdom is dead wrong. Years ago, before the Oliver Stone movie, I read way too many books about the Kennedy assassination and was convinced that elements of the CIA were involved (something I still find credible). Later I read a book about how the primary hypothesis about AIDS may well be wrong, and was, for a time, convinced. So I know that I need to temper my enthusiasm for this book.

In the last few years, I’ve had a couple of warning signs about my health. Minor problems, but they were the canaries in the coal mine, warning me that if I didn’t get my act together I’m heading towards obesity, heart disease maybe even diabetes. The first warning sign was my sleep apnea, which was diagnosed in 2003 and seemed to coincide with a gain in weight the year before. Then last year, it was my gallbladder. In my video journal, I talked about “food poisoning” in Scottsdale. After a few big restaurant meals, I experienced some rather nasty abdominal pains and nausea.

Finally after a particularly bad episode over Thanksgiving, I went to see the doctor. After an ultrasound, it was confirmed. My gallbladder was full of sludge which it was having trouble expelling into my digestive tract. Although I had no stones, I might eventually. This was not good. It could require surgery. However, he suggested we try another route. He gave me some medicine and told me to cut back on saturated fats and to exercise. We would meet back in a few months and see how I’m doing.

So that brings me to Taubes book. One of Taubes major points in his book is that fats (even saturated fats) are unlikely to be the kind of poison that we are led to believe. That maybe we don’t all need to be obsessed with cholesterol. And that the scientific evidence points towards refined carbohydrates like sugars, white flour and white rice as the main dietary factor in everything from heart disease to appendicitis. He has made a great argument so far that sugar and other refined carbohydrates are unambiguously bad for us. I’m not so convinced by his ambivalence towards saturated fat though.

I have been doing my own research, trying to find scientific studies published online that contain support for these ideas. Today I found this, a study from 90s which tried to identify risks for gallstones. This study did confirm that sugar likely plays a part in gallbladder problems:

A positive association between intake of refined sugars and risk of gallstone formation has been reported consistently. However, a diet rich in refined sugars is usually poor in complex carbohydrates and fiber; therefore, whether refined sugars and fiber have independent effects on gallstone risk remains to be fully clarified. Our findings suggest that refined sugars and fiber from cellulose may have independent effects.

Well what about fats?

The potential etiologic role of other fats has not been investigated thoroughly. Our study found no evidence of a link between polyunsaturated fats and risk of gallstone formation. The limited available evidence on the relation between these fats and gallstone formation is conflicting. The link between monounsaturated fats and risk of gallstone formation has not been investigated. Monounsaturated fats, as all fats, have been shown to have a powerful effect on the rate of gallbladder emptying. However, the effect is different from that of saturated fats because monounsaturated fats increase the ratio of HDL to LDL cholesterol and therefore may have important protective effects against gallstone formation.

Still the news was not so good for saturated fats, especially for men and saturated fats:

Of potential importance was the observed significant interaction in our study between sex and saturated fat intakes with regard to gallstone formation, indicating that the association between saturated fat intake and gallstone formation may be weaker in women than in men and that men in the highest quartile of saturated fat intake may be at greater risk than women.

You can see in this chart that the associated risk of saturated fat is much more significant for men.

The last week, I’ve shifted my diet towards an Atkins style diet. I’m no longer eating the ‘fat free’ versions of foods like yogurt and cottage cheese. I’m eating more meat (fish, turkey and chicken) and I even had a steak the other night. The main thing I’m restricting is sugar and other carbs. My doctor would not be pleased, but it has broken through my weight plateau. I am losing again. Now, I’ve got to pull it back. I don’t want to aggravate my gallbladder again. It has been getting better the last couple of months, and I can’t afford to be sick right now.