Gary Taubes is an investigative science journalist who has made a name for himself by questioning the science behind the U.S. dietary guidelines over the last 5 decades. He has a pair of New York times best selling books, "Good Calories, Bad Calories" and "Why We Get Fat and What You Can Do About It".
Another more recent 'science rebel' to gain fame is Dr. David Perlmutter, a neurologist who wrote the best seller, 'Grain Brain'. Recently, Dr. Perlmutter interviewed Gary. The result was an hour of invaluable information to better understand the real drivers of our country's obesity and diabetes crisis.
We have summarized the entire 55 minute interview below into a 5 minute read.
Why Did Gary Set Out To Prove American Dietary Science Is One Giant Mistake?
Gary did not set out to prove anything. He simply followed the data. As his friends in the physics department at Harvard had suggested, he found that nutrition policy in the United States over the last 5 decades appeared to be substantially flawed.
Dietary Guidelines Are Largely Based on Observational Studies and Bad Interventional Studies
Dr. Perlmutter opens with a question on the research, pointing out that much of the data used to defend grains and carbohyrdates as a staple of diet, and that fats should be avoided, are based on observational studies. Gary agrees, but also offers that interventional studies were done, but with bias and 'pathological science' and 'cognitive dissonance' -- essentially looking for evidence to defend an established opinion vs. objective evaluation. One such study that didn't support the researchers opinions, notably Ancel Keys--a University of Michigan Nutrition researcher and notorious advocate of blaming meat and animal fat for cardiovascular disease, was not published until 16 years after completion.
Scientists Have Known Obesity Was A Hormonal Disease Since The 1930's
Dr. Perlmutter then asked when Gary realized that 'energy balance' or 'calories in/calories out' was not an adequate explanation for weight gain. He says it was a gradual realization that became stronger and stronger over the years. To the point where now Gary believes that 'nutritional experts' saying healthy weight is a matter of calories in, calories out is like telling a person they are poor because they spend more money than they make, or a rich person is rich because they make more money than they spend.
Prior to World War II, German and Austrian researchers had seen obesity as a hormonal defect, but that research was forgotten about after the war. By the 1960's fat was being blamed for cardiovascular disease. Energy balance became the accepted theory.
Also in the 1960's, Insulin was identified as the hormone that enables fat storage. This should have led to recognizing the mechanism of obesity since insulin is elevated by a diet high in carbohydrates. The text books all clearly describe the role of insulin in storing excess energy as fat but the same books then talk about obesity being due to taking in more calories than a person burns.
Why Exercise Does Not Work For Weight Loss
Dr. Perlmutter then asks about Gary's opinion on exercise as a weight loss strategy. Gary says the energy expenditure hypothesis has been around 150 years but has no compelling evidence to support it. How much you eat and how much exercise are not independent variables, you can't manipulate one without manipulating the other. Essentially the more you exercise the more you drive appetite. Studies show the amount of calories you burn due to increased activity to be infinitesimally more than what you eat. Essentially exercise is not a good weight loss strategy. He's not saying that exercise is not beneficial general health, so don't get the wrong idea.
Dr. Perlmutter is quick to point out benefits to the brain of cardio exercise that he observes in his clinical practice, but that these are not strategies for weight loss or metabolic intervention.
But Low Carb Results in Ketosis, And That's Dangerious Right?
The next question is about Ketosis. Isn't this fat-burning state dangerous? Gary explains this comes from fears of type 1 diabetics getting to toxic levels of ketones (because they can't produce insulin at all) known as ketoacidosis. Then the fat fearing came along from the heart disease risk study, around same time as Atkins which is a high fat ketogenic diet. This raised concerns with health authorities and medical practitioners and so ketogenic diet developed a high risk reputation based on flawed data and beliefs.
Gary then goes into describing the evolutionary diet and how a state of ketosis was much more common since humans didn't regularly have access to fruits and starchy vegetation and survived on high fat animal based diets for extended periods. We certainly never had access to the refined grains and sugars of the last 150 years. To claim ketosis is dangerous is going against our own human evolution.
A Noble Obesity and Diabetes Research Initiative That The World Needs
Gary Taubes is now developing a research initiative called the Nutrition Science Initiative (NUSI) to conduct quality interventional studies to determine the causes of obesity and diabetes. It takes many millions of dollars. They've raised about 10 million dollars but it's a drop in the bucket compared to what's required to conduct all the studies needing to be done. The research is being done by many physicians and researchers who don't share Gary's opinions, but they at least agreed the research needs to be done and so while it has a long way to go, it's underway.
Why Gary Hasn't Focused on Gut Microbiome In His Obesity Research
Dr. Perlmutter then asks Gary whether his new book about the devastating health effects of sugar will include a chapter on the effect on the gut microbiome. Gary goes on to explain the big picture in what's driving the obesity epidemic, which is the intake of refined grains. He acknowledges the gut microbiome issue and admits he needs to include a chapter on it, but seems to believe it's more effect than cause although admits we need more research to figure that out. The question is whether the effects of our massive increase in refined grains intake can be corrected by adjusting gut bacteria. Gary offers that revising the intake of refined grains is what the evidence so far points to as the most beneficial change, and to think we could somehow justify these refined carb-based diets by manipulating gut microbiome is not likely to be the answer. It could be a piece of the answer but diet is what the research to date suggests is the 'elephant' driving the obesity and diabetes crisis.
Why It's Critical To Understand The Difference Between Clinical Outcomes and Population Studies
Gary then explains the difference between epidemiology studies which measure outcomes in populations measuring things like amount of animal protein eaten, with what physicians and dietitians are seeing in practice. In clinical practice physicians have dramatically improved outcomes with low carbohydrate, high protein and fat based protocols, yet the epidemiology studies say it's dangerous. He says that epidemiology studies make sweeping assumptions that can't account for all the factors of the individual patient.
Dr. Perlmutter offers that when physicians apply a low carb (which includes high intake of vegetables), protein & fat focused diet as part of a treatment it's not comparable to the populations studied in epidemiology research who are not generally health conscious and therefore eat lots of grain-fed, antibiotic treated meat, very little vegetables, are unlikely to exercise regularly, have lower education, lower paying jobs, are subject to more stress, more likely to smoke and less likely to get quality health care.
Essentially most physician directed diet results in restriction of refined grains and sugars, increased intake of vegetables and increased exercise and other stress lowering therapies. So to say the benefits come from the lowering of meat and fat intake is not likely to prove out and in fact Gary says the interventional evidence does not support this claim.
Our Own Clinical Experience Confirms This
Since we utilize a nutritionally ketogenic diet protocol in our clinics, we can definitely confirm the clinical outcomes of this approach as being highly effective in improving multiple health measures including BMI, blood sugar, blood pressure, blood lipids, inflammatory markers and many more. We agree with Gary in that the epidemiology studies are flawed have limited value from a clinical perspective.
Final Thought
That interview wrapped up there. Dr. Perlmutter explains his gratefulness for people like Gary Taubes who are cutting a path to improved nutritional science for generations to come. You can support the NUSI cause at NUSI.org.