Monday, August 03, 2009

book review of good calories,bad ca

In this groundbreaking book, the result of seven years of research in every science connected with the impact of nutrition on health, award-winning science writer Gary Taubes shows us that almost everything we believe about the nature of a healthy diet is wrong.

For decades we have been taught that fat is bad for us, carbohydrates better, and that the key to a healthy weight is eating less and exercising more. Yet with more and more people acting on this advice, we have seen unprecedented epidemics of obesity and diabetes. Taubes argues persuasively that the problem lies in refined carbohydrates (white flour, sugar, easily digested starches) and sugars–via their dramatic and longterm effects on insulin, the hormone that regulates fat accumulation–and that the key to good health is the kind of calories we take in, not the number. There are good calories, and bad ones.

Good Calories
These are from foods without easily digestible carbohydrates and sugars. These foods can be eaten without restraint.
Meat, fish, fowl, cheese, eggs, butter, and non-starchy vegetables.

Bad Calories
These are from foods that stimulate excessive insulin secretion and so make us fat and increase our risk of chronic disease—all refined and easily digestible carbohydrates and sugars. The key is not how much vitamins and minerals they contain, but how quickly they are digested. (So apple juice or even green vegetable juices are not necessarily any healthier than soda.)
Bread and other baked goods, potatoes, yams, rice, pasta, cereal grains, corn, sugar (sucrose and high fructose corn syrup), ice cream, candy, soft drinks, fruit juices, bananas and other tropical fruits, and beer.

Taubes traces how the common assumption that carbohydrates are fattening was abandoned in the 1960s when fat and cholesterol were blamed for heart disease and then –wrongly–were seen as the causes of a host of other maladies, including cancer. He shows us how these unproven hypotheses were emphatically embraced by authorities in nutrition, public health, and clinical medicine, in spite of how well-conceived clinical trials have consistently refuted them. He also documents the dietary trials of carbohydrate-restriction, which consistently show that the fewer carbohydrates we consume, the leaner we will be.

With precise references to the most significant existing clinical studies, he convinces us that there is no compelling scientific evidence demonstrating that saturated fat and cholesterol cause heart disease, that salt causes high blood pressure, and that fiber is a necessary part of a healthy diet. Based on the evidence that does exist, he leads us to conclude that the only healthy way to lose weight and remain lean is to eat fewer carbohydrates or to change the type of the carbohydrates we do eat, and, for some of us, perhaps to eat virtually none at all.

The 11 Critical Conclusions of Good Calories, Bad Calories:

1. Dietary fat, whether saturated or not, does not cause heart disease.
2. 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.
3. 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.
4. 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.
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.
7. Exercise does not make us lose excess fat; it makes us hungry.
8. 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.
9. 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.
10. 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.
11. The fewer carbohydrates we eat, the leaner we will be.

Good Calories, Bad Calories is a tour de force of scientific investigation–certain to redefine the ongoing debate about the foods we eat and their effects on our health.


Taubes's eye-opening challenge to widely accepted ideas on nutrition and weight loss is as provocative as was his 2001 New York Times Magazine article, “What if It's All a Big Fat Lie?” Taubes (Bad Science ), a writer for Science magazine, begins by showing how public health data has been misinterpreted to mark dietary fat and cholesterol as the primary causes of coronary heart disease. Deeper examination, he says, shows that heart disease and other “diseases of civilization” appear to result from increased consumption of refined carbohydrates: sugar, white flour and white rice. When researcher John Yudkin announced these results in the 1950s, however, he was drowned out by the conventional wisdom. Taubes cites clinical evidence showing that elevated triglyceride levels, rather than high total cholesterol, are associated with increased risk of heart disease—but measuring triglycerides is more difficult than measuring cholesterol. Taubes says that the current U.S. obesity “epidemic” actually consists of a very small increase in the average body mass index. Taube's arguments are lucid and well supported by lengthy notes and bibliography. His call for dietary “advice that is based on rigorous science, not century-old preconceptions about the penalties of gluttony and sloth” is bound to be echoed loudly by many readers. Illus. (Oct. 2)
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