Journalist Gary Taubes has written several books on diet, including “Good Calories, Bad Calories,” “The Diet Delusion,” “Why We Get Fat: And What to Do About It,” and most recently, “The Case for Keto: Rethinking Weight Control and the Science and Practice of Low-Carb/High-Fat Eating,” which is the topic of this interview.

For his most recent book, Taubes interviewed more than 120 physicians, plus a few dieticians and chiropractors and a dentist — about 140 medical practitioners in all — to understand the challenges that clinicians and patients face when trying to implement a ketogenic diet and lose weight.

The first half of the book explains how carbs and fats affect your body, and why replacing carbs with healthy fats is so important if you’re trying to control your weight and/or blood sugar. The second half of the book is a review of the lessons he’s learned along the way.

The Real Cause of Obesity

As noted by Taubes, on a global scale, the obesity epidemic can be linked back to a Western diet rich in refined sugars and grains. Whenever sugar and white flour are added to a population’s diet, regardless of what their baseline disease rate is, you eventually end up with an epidemic of obesity and diabetes.

The idea that you get fat because your caloric intake exceeds your expenditure is naïve, Taubes says. “That’s not the cause of obesity. That’s like saying we get rich because we make more money than we spend.” He also takes issue with the idea that obesity is a hormonal regulatory disorder.

“There are a lot of hormones that play a role in fat accumulation. Sex hormones primarily. But the hormones that link our diets to obesity are our insulin and glucagon,” he says. “I pretty much left glucagon out of the story because I don’t think we need to discuss it to know what the dietary treatment is.

So, when you’re talking about the influence of diet on obesity, it’s not because we eat too much. It’s not because we eat too much energy dense food. It’s [about] the glycemic index of the carbohydrates — how quickly can we digest the carbohydrates in our diet? And then the fructose content, the sugar content.”

Uphill Battle Remains Despite Strong Scientific Evidence

Unfortunately, Taubes estimates some 98% of conventional nutrition and obesity research community still approach obesity as an energy balance disorder. “They’ve been trained over their entire professional careers to think of obesity as caused by this imbalance in intake and expenditure,” he says.

“They believe it’s a direct consequence of the laws of thermodynamics. When they do research on this, they’re often not studying why people accumulate excess fat. They’re studying appetite and satiety and eating behavior, because they think that the reason why they accumulate fat can be explained if you can explain why they eat so much.”

On the upside, many physicians are now starting to understand the role of diet, processed grains and sugar in particular. Interestingly, the U.S. Department of Agriculture Dietary Guidelines Advisory Committee’s 2020 report claims there’s an insufficient amount of low-carb and ketogenic diet trials to suggest that this kind of diet would be beneficial for the American public at large.

This, despite the fact that hundreds of studies over the past two decades have consistently shown a ketogenic diet to be beneficial. “Name a disease state at the moment from Alzheimer’s to traumatic brain injury, and you’ll find somebody studying whether or not ketogenic or a low-carb/high-fat diet could be beneficial,” Taubes says.

In 2018, the American Diabetes Association Nutrition Committee published a consensus report¹ saying there was more consistent evidence for a low-carb or very low-carb diet being beneficial for Type 2 diabetes than any other diet tested, particularly ones that have been advocated by mainstream medical authorities, such as the Mediterranean diet and the DASH diet.

“So, clearly, the studies are out there,” Taubes says. “I think what we’re faced with is a sort of classic combination of cognitive dissonance and groupthink. When you spend your whole life believing something to be true and proselytizing about the truth of that supposed fact, it’s very hard to think otherwise, no matter what the research shows. 

The literature of cognitive behavioral psychology is full of studies and texts discussing this phenomenon. Cognitive dissonance … is what happens when a brain is confronted with evidence that something that brain has believed indisputably is wrong.”