Good Calories Bad Calories
Jed Stuber · Jan 01, 2011
The cover of this book shows a piece of toast with a pat of butter on it. The conventional wisdom for the past 60 years or so has been that the toast is good for you, and the butter is bad for you. Gary Taubes says the science of the last 150 years, right up to the latest research, has always indicated exactly the opposite.
Taubes set out to be a scientist, receiving an undergraduate degree in physics at Harvard and then a masters in engineering from Stanford. Somehow he ended up a writer instead, and he’s the only journalist to have won three Science in Society awards.
Taubes is well respected for being willing to challenge powers that be and entrenched views in science. One of his books showed that a Nobel winning physicist had probably falsified data to get funding, and another played a major role in exposing problems with cold fusion. As the subtitle of Good Calories, Bad Calories indicates, Taubes is again challenging the conventional wisdom, now in nutrition.
Conventional wisdom can be wrong of course. In November 2009 the conventional “scientific” wisdom was that the data showed that the world was getting warmer. Then the leaked emails from the University of East Anglia revealed contrary data that was being deliberately ignored.
There are also examples from the history of medical science. Ancient Greek doctors did practice bloodletting believing that it would release “foul humors” and cure disease. In 1847 a Hungarian doctor discovered that if doctors in hospitals washed their hands, the spread of disease was greatly reduced, and the death rate too! He spent 15 years trying unsuccessfully to convince doctors of a radical new notion that would end up being called “germ theory”, but he died before the idea was accepted. It wasn’t in time for the tens of thousands of Civil War soldiers, who in some historians estimation, suffered and died as much from the infections in their wounds as from the actual war wounds themselves.
What will people one hundred years from now think about our notions of medicine and nutrition? Taubes is convinced that they will be appalled at how our conventional wisdom has accepted one scientific view uncritically while ignoring other perspectives that actually have more evidence to support them. In Taubes estimation, future generations may be shocked about how we’ve misinterpreted, manipulated, and suppressed some aspects of the science of nutrition, weight, and disease.
First Taubes explains the historical background. Scientists as early as the 1820s had established that carbohydrates and sugars were fattening and wreaked havoc on the body’s endocrine system. Many were convinced that they created a chain reaction of problems in the body that led to diseases such as diabetes, heart disease, and cancer.
This view was well established in science and was itself the conventional wisdom right up into the 1950s. The science became more and more refined, more extensive studies were done, and evidence stacked up higher and higher. There was a series of famous books and doctors about this ranging from William Banting in the 1860s to Dr. Spock in the 1950s. These prominent spokesmen warned us all of the dangers of sugar and carbohydrates, and encouraged us to make sure to get plenty of the healthy, nutritious stuff, i.e. fats.
Then a most remarkable conceptual shift in the history of public health occurred. Ancel Keys, a researcher at the University of Minnesota, managed to set the agenda for funding of research on obesity and heart disease that still dominates today.
In the late 1940s, government funding of studies and organizations was expanding, a familiar story about the growth of the state in one more area. First it was millions being spent but now it’s billions annually.
By the 1970s Congress was publishing its own reports prescribing dietary advice to Americans. The mainstream media fell in line with the new conventional wisdom.
Keys made the cover of Time in 1961, and so began a long line of feature stories blaming fat and cholesterol for all the problems that had been attributed to sugars and carbohydrates just a few years earlier.
Taubes is certainly thorough. He spent six years researching and writing Good Calories, Bad Calories so he could personally examine all the major studies published, and he interviewed 600 clinicians, doctors, and researchers. The bibliography is nearly 70 pages long, and the references to people and studies can be daunting. Despite this thoroughness, he does write for the layman, and is known for explaining complicated concepts in a way everyone can understand.
Taubes’ primary findings are shown at the bottom of this post.
Summary of Highlights
Taubes and a host of accomplished scientists say that Ancel Keys was a bad scientist who was mostly wrong. Perhaps the most foundational erroneous assumption Keys made was that Americans’ diet changed radically in the 20th century and we ate more fat. This assumption was based on notoriously unreliable data. There’s just as much observational and statistical evidence that the trend was the opposite: less fat, replaced by mass produced, easily shipped and stored carbohydrates, plus the development of the widespread use of sugar. Keys and those who adopted his theory made a chain of logical assumptions that with which many scientists and studies disagree.
Another was that fat in diet causes high cholesterol in the blood. Many people erroneously assume this has been verified, but there haven’t been any major studies, even though Keys initially promised they would be done. To control and monitor fat content of people’s diets over a long period of time would be extremely difficult, if it could be done at all. These days it would cost billions to try, and there has never been a source of funding available. The fact is that no major attempt has ever been made, and most of the small scale studies that have been done indicate that fat in the diet does not cause cholesterol in the blood.
Keys and proponents of his theory instead rely on studies that they believe show a correlation between measured cholesterol in the blood and heart disease mortality. Of course, even if the statistical analysis showed that this correlation did in fact exist, that would not prove causation. Many studies of this type have been done, but Taubes says that Keys repeatedly committed a major violation of scientific protocol: selection bias. That is, he chose to include some data and not others. He shaped the data set to support his theory.
Some other developments exacerbated these problems that were already distorting the science. Proponents of Keys’ theory got into key positions and used the official stamp of government to create consensus. The fact that the more complex dietary studies hadn’t been done was forgotten. With government and funding behind Keys’ view, it was only a few years until science was focused on statistics that attempted to measure cholesterol levels across time and entire cultures. Most scientists were going into it assuming Keys’ theory was correct, and they were not even aware of the history of science that contradicted it. Based on extremely small shifts in percentages, scientists were concluding that dietary fat must cause heart disease.
Taubes goes on to explain that in addition to these problems, which are troubling enough, companies trying to develop drugs that were supposed to lower cholesterol brought massive funding into the picture. Drug industry-driven research is another area in which conventional wisdom often does not take into account the latest science or the full picture. There are some studies indicating that the drugs may lower the amount of cholesterol in the blood, but only by miniscule amounts. Furthermore, mortality rates for those who take the drugs and lower their cholesterol are not any better than those that don’t.
Again, Taubes is no lone prophet crying in the wilderness on this topic. There are many scientists and researchers making these points. There is an international organization for scientists and doctors calling for a stop on prescribing the drugs. The drug aspect of the story has occasionally come up in the mainstream media, such as in a well known cover story in Business Week. A doctor quoted in that article wonders why people would pay thousands of dollars and endure side effects to take these drugs, when they won’t live longer. Of course Business Week was covering the angle of whether it was wise for companies to provide insurance coverage for these drugs as a benefit to employees.
Yet another aspect of the science that is not well understood is the complexities of trying to measure cholesterol in the blood. The popular level assumption is that it is a simple, reliable, objective test. However, in most cases when doctors test cholesterol they have no way of knowing how it is apportioned into various lipoproteins, of which there are at least three classes and many subtypes.
Lipoproteins were being measured and studied in high tech labs by the 1950s. Even back then, some prominent scientists were arguing that carbohydrates and sugars, and not fats were having effects on the lipoproteins, thereby raising total cholesterol in the blood. Their research has continued down through the decades, and the evidence mounts, but it seems to be ignored outside of a few smaller circles in the scientific community. Doctors still do not seek out or have access to the specialized labs that can show more extensive breakdowns of lipoproteins in blood.
This history of the fat-cholesterol hypothesis is what Taubes focuses on in Part One of his book. He believes that dependable science has clearly established that the hypothesis is simply wrong.
The second part of his book goes on to present evidence that sugars and carbohydrates may be at the root of all “diseases of civilization” which include diabetes, heart disease, and cancer, but also many other things such as auto-immune diseases like multiple sclerosis and Alzheimers. Taubes believes that science is well on its way to proving that sugars and carbohydrates cause a chain reaction of metabolic problems that lead to these problems. Scientists are still working on the details of the processes that happen in the body, but at the very least the role of sugars and carbohydrates causing the insulin regulation problems of diabetes is very well established. In spite of this body of research, official dietary advice of the U.S. government and many other health organizations deny any relationship between a high carbohydrate diet and diabetes. This area is another in which scientific evidence goes back 150 years, but is ignored. Taubes proposes that more large scale studies need to be done in this area to solidify the science, but there does not appear to be establishment interest in funding this research.
The third part of Good Calories, Bad Calories delves into obesity and the regulation of weight. First he points out another mistaken assumption: all calories are alike. While it is true that a calorie is a measurement of energy regardless if it is from carbs, fat, or anything else, the problem with such a simplistic notion is that calories from different nutrients can have radically different effects on metabolism and hormone secretion. It’s also important to remember that the energy moving in and out of the body is not a zero sum game. It is not necessarily true that a hundred calories of food eaten is offset by 100 calories worth of exercise. Our cells and tissues require and expend the energy we consume, and this is regulated by metabolism and hormones.
Another simplistic assumption is that exercise creates a negative energy balance so that the body burns fat, leading to weight loss. Depending on metabolic factors, the body can both need energy, meaning a person is hungry, and not be able to access the energy in stored body tissues.
In the final chapters Taubes proposes that more studies are needed to follow up on the promising science of the effect of high carbohydrate diets on insulin, and the key role insulin plays in hormonal and metabolic functions of the body.
Taubes keeps his focus on the scientific studies in this book, not providing dietary advice. That is the subject of another book to be released on December 28 (after this newsletter goes to press). It is titled Why We Get Fat and What to Do About It, and has created quite a buzz. After all, a lot of people are extremely curious why he thinks the science says that we should eat more butter and be concerned about the toast.
Gary Taubes blogs at www.garytaubes.com.
Excerpt: Ten Findings
- Dietary fat, whether saturated or not, is not a cause of obesity, heart disease or any other chronic disease of civilization.
- The problem is the carbohydrates in the diet, their effect on insulin secretion and so the hormonal regulation of homeostasis—the entire harmonic ensemble of the human body. The more easily-digestible and refined the carbohydrates, the worse the effect on our health, weight and well-being.
- Sugars—sucrose and high fructose corn syrup specifically—are particularly harmful, probably because the combination of fructose and glucose simultaneously elevate insulin levels while overloading the liver with carbohydrates.
- 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 diseases of civilization.
- 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. Expending more energy than we consume does not lead to long-term weight loss; it leads to hunger.
- Fattening and obesity are caused by an imbalance – a disequilibrium—in the hormonal regulation of adipose tissue and fat metabolism: Fat synthesis and storage exceeds the mobilization of fat from the adipose tissue and its subsequent oxidation. We become leaner when the hormonal regulation of the fat tissue reverses this balance.
- 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.
- By stimulating insulin secretion, carbohydrates make us fat and ultimately cause obesity. The less carbohydrates we consume, the leaner we will be.
- By driving fat accumulation, carbohydrates also increase hunger and decrease the amount of energy we expend in metabolism and physical activity.