I finally had a chance to finish Gary Taubes' book Good Calories, Bad Calories, and all I can really say is, "Wow!"
Taubes' 600-page book is the culmination of five years of work researching a century worth of epidemiological and clinical research into the carbohydrate and fat hypotheses regarding physiology, metabolism, obesity, and the "diseases of civilization" - coronary heart disease, diabetes, cancer, dementia, etc. The volume, which includes some 70 pages of bibliographical references, is divided into three sections: a history of the fat-heart disease hypothesis, a history of the carbohydrate-heart disease hypothesis, and a history of the fat-obseity and carbohydrate-obesity hypotheses.
Taubes reviews this century-worth of data, and comes to the following conclusions:
- Dietary fat, whether saturated or not, does not cause heart disease.
- Carbohydrates do, because of their effect on the hormone insulin. The more easily-digestible and refined the carbohydrates and the more fructose they contain, the greater the effect on our health, weight, and well-being.
- Sugars—sucrose (table sugar) and high fructose corn syrup specifically—are particularly harmful. The glucose in these sugars raises insulin levels; the fructose they contain overloads the liver.
- Refined carbohydrates, starches, and sugars are also the most likely dietary causes of cancer, Alzheimer’s Disease, and the other common chronic diseases of modern times.
- Obesity is a disorder of excess fat accumulation, not overeating and not sedentary behavior.
- Consuming excess calories does not cause us to grow fatter any more than it causes a child to grow taller.
- Exercise does not make us lose excess fat; it makes us hungry.
- We get fat because of an imbalance—a disequilibrium—in the hormonal regulation of fat tissue and fat metabolism. More fat is stored in the fat tissue than is mobilized and used for fuel. We become leaner when the hormonal regulation of the fat tissue reverses this imbalance.
- Insulin is the primary regulator of fat storage. When insulin levels are elevated, we stockpile calories as fat. When insulin levels fall, we release fat from our fat tissue and burn it for fuel.
- By stimulating insulin secretion, carbohydrates make us fat and ultimately cause obesity. By driving fat accumulation, carbohydrates also increase hunger and decrease the amount of energy we expend in metabolism and physical activity.
- The fewer carbohydrates we eat, the leaner we will be.
I found the book to be an enjoyable, if dense, read. While Taubes of necessity sometimes gets into the scientific and physiological details, in general he keeps the prose at an understandable level. With the exception of the forward, which I found to be a bit tedious in my first attempt to read, the book is a page-turner, and reads much like investigative journalism.
The preponderance of the evidence - and if you wish to refute it, start with that 70-page bibliography of references - clearly sides with Taubes' conclusions. Perhaps the most controversial aspect of this book is not Taubes' conclusions, but rather the implied indictment of the medical research community with respect to hypothesis regarding the connections between fat, carbhoydrates, heart disease, metabolism, and obesity. That indictment is perhaps best summarized in this line from the Epilogue:
The urge to simplify a complex scientific situation so that physicians can apply it and their patients and the public embrace it has taken precedence over the scientific obligation of presenting the evidence with relentless honesty. The result is an enormous enterprise dedicated in theory to determining the relationship between diet, obesity and disease, while dedicated in practice to convincing everyone involved, and the lay public, most of all, that the answers are already known and always have been - an enterprise, in other words, that purports to be a science and yet functions like a religion.
This book puts the imprimatur on what I have been saying for almost a decade: There is absolutely no rigorous, scientific evidence that dietary fat causes heart disease or obesity. To the contrary: plenty of bona fide evidence places the blame squarely upon the over-consumption of refined carbohydrates.
Simply put: if you care about your health and nutrition, read this book. Come to your own conclusions. But if you want to argue the dietary fat-heart disease or dietary fat-obesity hypotheses, then you'd better read this book first, or else you will only make a fool of yourself.