Friday, January 28, 2011

The Nutrition Debate #5: Gary Taubes and the Alternative Hypothesis

Gary Taubes first came to my attention as a result of the New York Times Sunday Magazine cover story of July 7, 2002, entitled, “What If It’s All A Big Fat Lie?” Taubes has won the Science in Society Award of the National Association of Science Writers three times, but his 2002 article was the first widely read refutation, for a popular readership, of the “high dietary fat/cholesterol/heart disease” (lipid) hypothesis. It also posited his “alternative hypothesis,” which is predicated on a very low carb way of eating. I didn’t know it at the time, but my doctor, an internist/cardiologist, had read the article and tried such a diet himself to lose weight. He succeeded and recommended that I try low carb eating too, also to lose weight. As an afterthought, he said, “By the way, it will probably help your Type 2 diabetes.” Boy, was he ever right about that!

Following the publication of his 2002 NYT article, Taubes was besieged to write a book detailing his findings and touting the “alternative hypothesis.” He refused and instead spent the next five years researching and writing “Good Calories – Bad Calories” (Alfred A. Knopf, 2007). He refused to produce a book for the popular readership because he said he did not want to produce a polemic. He wanted instead to research and present a history and analysis of all that has transpired in the field of obesity research and “science” – a word he uses sparingly and advisedly. This book is a very dense read, but getting through it is well worth the slog. In the end, in the Epilogue (pages 453-454), he proffers 10 “certain conclusions,” which I present in full below.

“As I emerge from the research, though, certain conclusions seem inescapable to me, based on the existing knowledge:

1. Dietary fat, whether saturated or not, is not the cause of obesity, heart disease, or any other chronic disease of civilization.
2. The problem is the carbohydrates in the diet, their effect on insulin secretion, and thus the hormonal regulation of homeostasis – the entire harmonic ensemble of the human body. The more easily digestible and refined the carbohydrates, the greater the effect on our health, weight, and well-being.
3. Sugars – sucrose and high-fructose corn syrup specifically – are particularly harmful, probably because the combination of fructose and glucose simultaneously elevates insulin levels while overloading the liver with carbohydrates.
4. Through their direct effect on insulin and blood sugar, refined carbohydrates, starches, and sugars are the dietary cause of coronary heart disease and diabetes. They are the most likely dietary causes of cancer, Alzheimer’s disease, and the other chronic disease of civilization.
5. Obesity is a disorder of excess fat accumulation, not overeating and not sedentary behavior.
6. Consuming excess calories does not cause us to grow fatter, any more than it causes a child to grow taller. Expending more energy than we consume does not lead to long-term weight loss; it leads to hunger.
7. Fattening and obesity are caused by an imbalance – a disequilibrium – in the hormonal regulation of adipose tissue and fat metabolism. Fat synthesis and storage exceed the mobilization of fat from the adipose tissue and its subsequent oxidation. We become leaner when the hormonal regulation of the fat tissue reverses the balance.
8. Insulin is the primary regulator of fat storage. When insulin levels are elevated – either chronically or after a meal – we accumulate fat in our fat tissue. When insulin levels fall, we release fat from our fat tissue and use it for fuel.
9. By stimulating insulin secretion, carbohydrates make us fat and ultimately cause obesity. The fewer carbohydrates we consume, the leaner we will be.
10. By driving fat accumulation, carbohydrates also increase hunger and decrease the amount of energy we expend in metabolism and physical activity.”

I’ve read “Good Calories – Bad Calories” twice, and re-read Taubes’s “certain conclusions” at least a dozen times. I am convinced that he’s got it right. But, after failing to get the reception he had hoped for in the medical community, Taubes finally relented and agreed to write a book that would be a little more accessible to the general public. Gary Taubes’s “Why We Get Fat: And What to Do About It” was published by Alfred Knopf last week (December 28, 2010). I’ve pre-ordered a bunch. Hardcover: $24.95. Amazon (hardcover): $13.41.The Kindle (Amazon) eBook edition is $9.99.

Next installment: The “Energy In – Energy Out” theorem: an alternate interpretation.

© Dan Brown 1/2/11

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