Why Is Nutrition So Confusing?
Too much on your plate? Or too little? Or too much of the wrong stuff? In an interview which I conducted recently for Sight and Life magazine, the influential thinker Gary Taubes gives us his take on why the simple business of eating can seem so perplexingly complex.
Gary Taubes
Gary Taubes is the co-founder of the Nutrition Science Initiative (NuSI.org) and an American science and health journalist. He is the author of Nobel Dreams (1987), Bad Science (1993), Good Calories, Bad Calories (2007) – which is titled The Diet Delusion in the UK – and Why We Get Fat (2011).
Gary has won the Science in Society Award of the US National Association of Science Writers three times, and is the recipient of a Robert Wood Johnson Foundation Investigator Award in Health Policy Research.
He talks to Sight and Life about why he thinks nutrition is so confusing and what should be done about it.
Sight and Life (S&L): You founded the Nutrition Science Initiative (NuSI) in 2012, Gary. What was your objective, and what have been your experiences to date?
Gary Taubes (GT): Let me answer by providing the context in the form of my professional background. I’ve been an investigative science journalist since the early 1980s, focusing on controversial science and what physicists call “pathological science”, or the “science of things that aren’t so.” In the early 1990s I began focusing on research in public health, in large part because it didn’t live up to the strict requirements that I had learned from my previous investigations were absolutely necessary for the establishment of reliable knowledge – the key word being “reliable.”
This led me into a series of investigations, first for the journal Science and then for the New York Times Magazine, and to my first book on nutrition research. One of my conclusions was that our dietary beliefs were based more on the preconceptions of influential researchers than on rigorous experimental evidence. In fact, many of these beliefs had arguably failed the experimental tests to which they had been subjected, yet nutrition authorities continued to treat them as facts. It was a field based on preconceptions, assumptions and faith, and while the guidance based on these preconceptions began to be promulgated widely, it coincided with unprecedented increases in the incidence of obesity and diabetes.
“In nutrition, we can always blame the public for not following our advice”
In other fields of medicine, a natural response would have been to question our understanding of these disorders. Governmental organizations would have established teams of researchers to figure out where we went wrong and why, and to put an end to these epidemics. But in nutrition, we can always blame the public for not following our advice and the food industry for making it too hard for the advice to be followed, and we never have to question our beliefs.
I co-founded the Nutrition Science Initiative with Dr. Peter Attia to try and rectify the situation. NuSI’s strategy is to fund and facilitate the experimental trials in humans that are necessary to establish reliable knowledge about the nature of a healthy diet, and to recruit the nutrition/chronic disease research community as allies in this endeavor. This requires convincing the research community of the need to do these trials; it requires raising the money for the trials and raising enough money so that the trials are rigorous and provide reliable results that answer the right questions; and it requires getting those studies done and applying the highest possible standards.
So far we’ve had success with recruiting leading members of the research community as allies. These researchers acknowledge the inherent uncertainty in their beliefs and welcome the opportunity to rigorously test them. We’ve raised the philanthropic funds necessary to support the first three critical trials, the details of which can be viewed on our website (http://nusi.org/). We’re now engaged in recruiting the researchers for the next phase of clinical trials and raising the money to fund them.
S&L: You are a prolific author, with recent book publications including “Why We Get Fat” (2011) and “Good Calories, Bad Calories” (2007). What drives you to publish so widely?
GT: “Prolific” is in the eye of the beholder. It took me five years to research and write Good Calories, Bad Calories, and that came after two to three years of research and writing. Why We Get Fat, as I explain in the book’s introduction, is something of an airplane-reading, argumentative version of GC,BC. It was written to be read quickly by those who don’t have the time for the 500-page, densely-annotated tome of GC,BC, the subtext of which is “much of what you think you know about nutrition is likely wrong.”
“To do science right requires the rigorous testing of our hypotheses”
S&L: On February 8, 2014 The New York Times published an opinion piece by you entitled “Why Nutrition Is So Confusing”. The home page of NuSI asks, “Can we trust anything we think we know about nutrition?” Why is nutrition confusing, in your opinion, Gary, and why should we be mistrustful of what we are told about it?
GT: This isn’t a simple question, and no short answer will do it justice. Still, I’ll try. To do science right, to generate reliable knowledge about nature and the universe, requires a meticulous attention to detail and the rigorous testing of our hypotheses. This is doable in hard sciences like physics because physicists are not dealing with messy complicated subjects such as human beings, who happen to have minds of their own. Experiments might be expensive, but they can be reproduced numerous times, and variables can be controlled in such a way that the researchers can establish, beyond reasonable doubt, what is cause and what is effect. Nutrition, on the other hand, asks questions about how diet influences human health over the course of a lifetime. This means doing the studies in humans and following them for years or decades to get meaningful results.
This combination makes the experiments extraordinarily difficult, and they can appear prohibitively expensive. I believe that nutrition researchers have tended to respond to this by accepting a lower standard of evidence for what they are willing to believe and promulgate as advice. What’s undeniable (to me, anyway) is that the evidence is ambiguous, and it then leaves the interpretation open to the preconceptions of the “experts” who are doing the interpreting. If you believe observational trials are capable of establishing cause and effect (I don’t, with a few dramatic exceptions), then you interpret the evidence one way, and that informs your belief system on what constitutes a healthy diet. If you believe randomized controlled trials are necessary to establish cause and effect (I do, but acknowledge that these too can be done poorly), then you interpret the evidence another way.
We end up with today’s news in health and nutrition contradicting yesterday’s news, which contradicted the news from the day before, while the experts are content to disagree with each other. At the heart of the problem is a research community that never succeeded in the job of establishing reliable knowledge, and doesn’t understand – or at least agree – that when the evidence is ambiguous, you have to acknowledge this, even when you’re trying to get the public to do what you think is best.
S&L: In an article published in the BMJ on April 17, 2013 entitled “The science of obesity: what do we really know about what makes us fat?” you question the received wisdom concerning the causes of obesity. Could you enlarge on this?
GT: Prior to World War II, when effectively all meaningful medical research was done in Europe, German and Austrian clinical investigators had mostly come to believe that obesity was indeed a hormonal/regulatory defect, just like any other growth disorder. This hypothesis vanished with the war and with the shift of the lingua franca of science from German, pre-War, to English, post-War. After the war, young American MDs and nutritionists decided obesity was obviously caused by gluttony and sloth – simply eating more calories than we expend – and that’s the notion we’ve been living with since.
To get an idea of the problems with this thinking, ask yourself why it’s any more meaningful to say that someone got fat because they took in more calories than they expended, than that someone got rich because they took in more money than they spent. In both cases, the statement is true, but only in a vacuous sense. Someone who gets rich takes in more money than they spend, but this says nothing about how they got rich – which is usually what we want to know. The same is true for someone who gets fat. Sure they take in more calories than they expend, but the question is why?
The pre-World War II Europeans thought the key would be in why the fat cells themselves might accumulate excess fat and why the oxidation of that fat as fuel might be inhibited. By the 1960s, biochemists and physiologists had established that the hormone insulin regulates fat accumulation in fat cells and inhibits fatty acid oxidation in mitochondria. When insulin levels go up, we store fat. When insulin goes down, we mobilize it and oxidize it. The catch is that we secrete insulin primarily in response to the carbohydrate content of our diet. So from this biological perspective – rather than the calories-in-calories-out physics viewpoint – what makes us fat is whatever serves to elevate insulin levels, and that’s probably the quantity and quality of carbohydrates in our diet. This hypothesis was embraced by diet book doctors – Robert Atkins, most notably – and treated by the mainstream medical community as quackery. Since the 1960s, the diet books have advocated reducing carbohydrates, and the medical/public health establishment has insisted this is quackery and that “eat less, exercise more” is the only meaningful advice for obesity.
S&L: In the same article, you stress the importance of studying not only medicine but also the history of medicine. Why is history so important for our understanding of contemporary medical problems?
GT: My college education was in physics, and this is how physics is taught. You learn how the science evolved over centuries – what we once believed, how new evidence and new hypotheses shifted those beliefs, what the tests of the hypothesis did or didn’t find – even who conducted the tests and who promulgated the hypothesis. You get a firm grounding in the methodology of science, and how science proceeds in fits and starts, and the role played by theorists and experimentalists. By leaving out the history, we teach dogma. Students accept what they’re taught as the gospel truth without the necessary context to question it.
One of the fascinating aspects of my research was learning which clinicians thought up the idea that obesity was caused merely by taking in more calories than we expend (there were two in particular, Carl von Noorden in Germany and Louis Newburgh in the USA), and how this notion was challenged, and why. It was a hypothesis put forth by a couple of reasonably smart guys at a time when studying the caloric content of foods and caloric expenditures of humans and animals was the new big thing in research. It was accepted after World War II because an entire school of research that thought otherwise evaporated with the war. The question, of course, is whether it’s actually right. I’d argue no.
S&L: According to your article “Why Nutrition Is So Confusing”, obesity and its related diseases cost the US health care system alone more than US$1 billion per day. Why has the global phenomenon of obesity developed so rapidly, in your opinion, what are its causes, and what can be done to combat it?
GT: I have a bias based on my research, but I think it’s the spread of sugars, first and foremost – sucrose and high fructose syrups – and then the refining of the carbohydrates we consume. White flour. I don’t think it’s the amount we eat and exercise, but rather the change in the macronutrient composition of the diet. We eat unprecedented amounts of sugars, and I think this is reflected in unprecedented rates of obesity and diabetes. You can see this in microcosms as well – the south Pacific Atoll of Tokelau, for instance, which went from having virtually no diabetes and eating very little sugar in the 1960s to having the highest rates of diabetes in the world today and having a yearly sugar consumption of 100 pounds per capita. Yes, this is an association and it doesn’t imply causality. But you see the same patterns in geographically diverse populations going back well into the 19th century. To me, it’s compelling. But I also think that this can be tested with the proper experimental trials, and I’m hoping we’ll get that done within the next decade.
“We shouldn’t fool ourselves into thinking we understand what’s causing these disorders”
S&L: At a time when nutrition is receiving a prominent place on the global development agenda, you are questioning the science on which many of our assumptions about nutrition are based. What are the reasons for your skepticism, and what would you propose by way of alternative approaches?
GT: As you noted, obesity rates are sky-rocketing around the globe, as are diabetes rates, and they’re doing so during a period of time in which we think we understand the dietary triggers of these diseases. So we either 1) blame the individuals for not taking our advice, or 2) blame the food industries for making it too difficult to follow our advice, or else 3) maybe our advice and our understanding are wrong. Anyone who doesn’t entertain the possibility that the third answer is the correct one is someone, I’d argue, who doesn’t comprehend the role that skepticism plays in a functional science. Richard Feynman, the Nobel laureate physicist, once said that the first principle of science is that you must not fool yourself, and you’re the easiest person to fool. With the ongoing epidemics of obesity and diabetes in the world, I think it’s incumbent on us not to fool ourselves into thinking we understand what’s causing these disorders.
S&L: If communications about nutrition are currently confusing, how would you improve them, Gary?
GT: I believe that the communication is confusing because the evidence on which we base our communications is ambiguous. I think there are a lot of nutritional authorities out there promulgating their beliefs as irrefutable facts. We can start by acknowledging that what we believe to be true is only what we believe to be true. Then we can work to develop the tests necessary to see if we’re right. Yes, the public might get frustrated if nutritionists start acknowledging that they’re more than occasionally speculating, but is that any worse than insisting that we know the truth when we don’t, and possibly doing more harm than good?
S&L: Thank you for sharing your views with us. I hope that some of readers will respond with their views in the next issue!
GT: Thank you.
Gary Taubes was interviewed by Jonathan Steffen.
First published in Sight and Life magazine VOL. 28(1)| 2014. Please click here to read the original article.
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