After acquiring the book almost a year ago, I (again) started reading Gary Taubes’ book entitled Good Calories, Bad Calories. Based on what I’ve read so far, and knowing Gary Taubes’ background, I believe it’s a very scholarly work, and very thoroughly researched. From the title, it’s obvious that this book considers the scientific evidence for specific types of diets and how they affect body weight regulation.
In the first part of the book, in order to draw parallels with current scientific evidence for the “epidemics of obesity and diabetes,” he puts forth a detailed historical analysis of the decades-long debate on the correlation, or causation, of heart disease with dietary fat intake. The upshot of this work is to point out what happens when a researcher, who becomes prominent for various reasons, can influence health care policy even when the researcher’s scientific data are far from conclusive. In this particular case, Taubes discusses the work of the prominent physiologist Ancel Keys, who was convinced, based on his research that the rise in incidence of heart disease in the developed world from the 1920s through the 1950s was due to increased blood cholesterol levels, which was in turn due to increased total dietary fat intake. Keys was apparently a formidable character who felt very strongly that his data conclusively proved this hypothesis, and was very quick to strongly criticize those who opposed his theories. Throughout this time period, and even into the 1960s, there were many prominent researchers who had serious reservations, based on scientific analysis of his data as well as their own, that Keys’ results were inconclusive. Nevertheless, because Keys was so forceful, Taubes brings various elements to show that the media picked up Keys’ theories, and physicians began to recommend low fat diets to their patients, despite lack of strong scientific evidence for increased dietary cholesterol intake (mainly from animal fats) causing a rise in heart disease.
In such a scenario, the question becomes one of correlation versus causation, i.e., depending on how solid the scientific evidence is for any given observed public health phenomenon, one might be able to say there is a CORRELATION of a dietary trend with observed disease incidence, rather than being able to state, through a solid base of scientific evidence, that a given dietary trend CAUSES disease. This concept is one that the Health at Every Size paradigm considers regarding current dietary habits with the incidence of “obesity” and diabetes. The bottom line is that there is still much scientific work that needs to be done to determine whether lifestyle in the developed world causes, versus merely correlates with, “obesity” and diabetes.
One reason for this phenomenon of correlation overpowering the media is that it provides a solid message to address what appears to be an alarming trend. Understandably, people don’t have the patience to wait for conclusive scientific evidence to be produced when faced with a potentially scary scenario. When scientific evidence that contradicts the popular theory is published, it tends to be ignored, because it doesn’t fit what has become DOGMA, based on the popular correlation. Taubes skillfully points out that when correlations are not thoroughly researched scientifically, and they become socially accepted dogma, real scientific progress just breaks down. Ultimately, I believe, the truth always emerges in the end, and the road of public health history is littered with the corpses of what used to be very popular theories. But while the dogma exists, well meaning but misguided health professionals may in fact do more harm than good, by encouraging unrealistic weight loss goals rather than focus on lifestyle changes.