Gary Taubes is an investigative journalist, not a doctor, but he may be the world’s most significant advocate for ketogenic and low-carbohydrate diets. Taubes’ reporting over the last two decades has comprised the definitive political and scientific history of low-carb nutrition. Why were grains put at the bottom of the food pyramid? Why were we taught to fear saturated fat? Why do conventional diets almost never seem to work? We owe our understanding of these issues, to a large degree, to Gary Taubes.
When Taubes began telling this story, very few medical professionals were prepared to entertain the idea that the conventional wisdom on obesity and nutrition could be so profoundly wrong. That tide has now turned, as shown by the remarkable growth of the keto movement in recent years.
Taubes’ latest book, The Case for Keto, will be released today. It consolidates much of what he’s learned during his career, and puts forth what might be the best possible argument for carbohydrate restriction—concise yet comprehensive.
I was lucky enough to spend an hour with talking with Taubes about his new book, obesity, diabetes, and his perspective on the nutrition movement that he helped bring to life:
You started writing about low-carbohydrate diets over 20 years ago, when there was very little open support in the medical community for your interpretations. And now you’ve been validated by more than a few experts. What does it feel like?
There are two ways to look at it.
Back in 2002, when I wrote my New York Times Magazine article [“What if It’s All Been a Big Fat Lie?”], I bet you could count on your fingers and toes the number of physicians in the country who were prescribing these diets. And again, half of them had written diet books.
Now I figure there are a few tens of thousands. I make that estimate in part because there’s this Facebook group, just in Canada, of 4,000 women physicians who eat this way. That’s just women physicians, just Canada. So, a few tens of thousands worldwide seems like a modest estimate.
That’s great, but that’s still a tiny, tiny percentage of the medical community. The relative increase is from millionths of a percent to maybe one percent. And what I’m interested in is the other 99%, and that’s what I tend to pay attention to.
Most people in the medical community just don’t get it. They either don’t think about this, or they think that people like me are quacks.
I do get emails from people describing how they’ve started on a low-carb diet with the intent of eating this way forever, and that means a lot to me.
So, there’s a sense of accomplishment that I’m part of this movement now, and it’s a movement that I helped start. But I like to joke that Don Quixote is my role model, that there’s an endless array of windmills to joust at. Although more often than not they knock you off the horse on the way by.
Should everyone should eat a ketogenic diet?
The people that are metabolically healthy already – they can eat fruits, vegetables, whole grains, beans, legumes. I’d suggest they stop drinking sugary beverages, stop getting 20% of calories from sugar, and they’ll be much healthier still, but that’s about it.
The key issue is that some of us can’t tolerate the carbohydrates. We have to eat [low-carb/keto] to be healthy. Meanwhile, the healthy people, the ones giving advice, are just assuming that we can eat like they can eat. The consensus is that we’re just like them, we just eat too much. They think they know what a healthy diet is, that we should eat their version of a healthy diet, just eat less and we won’t get fat or diabetic or hypertensive or pick your chronic disease. And that’s just not true.
One of the fundamental points of the book is the idea that excessive weight gain is caused by metabolic dysfunction. Genetics matter, and diet matters, but willpower – the conscious decision to eat more or eat less – matters very little at all.
The conventional wisdom on obesity is that the only difference between fat people and thin people is how much they eat and exercise. Thus, if we stay fat, we lack the willpower to do what’s necessary. That’s not true either.
You explain that the energy balance hypothesis and the rules of thermodynamics, the general idea of “calories in, calories out,” are all accurate, they’re just not relevant.
Right, they’re not relevant to why people get fat, any more than they’re relevant to why I’m 6’2” and someone else is 5’3”. If you’re obese, is it because you eat too much? Or is it the other way around: that you’re hungry all the time because your body is trying to accumulate fat?
When I wrote in The Case Against Sugar I had a chapter called “The Gift That Keeps on Giving” about the energy balance hypothesis. If you assume that obesity is just caused by eating too much, then there’s nothing wrong with sugar, other than that people like it too much. It’s been this gift for the sugar industry, that they can always use this defense: “People like it too much. What’s wrong with that?”
Now whenever I interview an obesity researcher I’ll ask them, “what’s the difference between somebody who gets fat and somebody that stays lean?” And other than the latter eating too much, they can’t give an answer.
You speculate that almost all diets, when they work, work for the same reason that keto does: they allow the dieter to spend more time under the insulin threshold, the point at which the body burns fat instead of storing it.
Right, the conventional wisdom is that diets work when we eat less and they put you into “negative energy balance.” What I and others have been arguing is that diets only work when they lower insulin, because that’s what has to happen such that your fat cells will mobilize the fat they’ve stored and your lean tissue burn that fat for fuel. So that’s the goal. And that’s why some sort of carbohydrate restriction is necessary.
Let’s talk about low-carb diets and diabetes. I have Type 1 diabetes, and most of our readers have diabetes of some sort, or care for someone with the condition.
The book I’m trying to write now is specifically on diabetes.
I’ve been doing what I always do, which is spending months reading the history. I have probably 1,000 articles in my files, of which 500 are from pre-1940, because that’s what’s so fascinating to me. It’s a really interesting story. Basically, the diabetes specialists just never got around to testing whether there was any ideal diet for Type 1 diabetes, or Type 2 for that matter. Once insulin came along, they started pumping carbohydrates into you guys to balance the insulin. And there was a lot of debate about how liberal the diets should be, and then the Ancel Keys heart disease story comes along, and it’s just “give everyone carbs” and make sure they don’t eat fat because that’s deadly. And they simply never tested whether there was a better way or why anyone might want to prioritize blood sugar control over anything else.
And somebody like Bernstein comes along and he’s actually got the disease himself and he says “let me see what works best for me” and it’s very low-carb. And rather than saying “Hey, this is interesting, let’s test it,” the experts just say “well that’s too much trouble” and ignore him.
Have you met Dr. Bernstein? He’s a hero of ours.
He’ll be in the next book. Over Christmas last year  I drove from my in-laws in Westchester over to Mamaroneck, and spent about 6-7 hours with him. Every science needs somebody like him, but you also need a community that can recognize him.
The other thing that fascinates me is that the diet he settled on was basically the same diet that was prescribed before the discovery of insulin. It was the standard of care.
The diet that would let a patient with Type 1 live for 6 months instead of 6 weeks.
Yeah, exactly. And for a patient with Type 2 it kept them alive indefinitely.
Pre-insulin the accepted dietary therapy for both types of diabetes was an animal diet with green vegetables, and you’d boil the green vegetables three times to get out any carbohydrates in them. Even back in the 1860s, there are textbooks in which they’re saying clearly these are safe diets, because there are populations that eat this way, like the Inuit. Elliott Joslin said it in his first textbook – we know that people can sustain high fat diets because the Inuit do it.
So, it wasn’t that radical to say that maybe the diet that’s best without insulin is the diet that’s best with insulin. Let’s test that! They just never did it. And once they started doing randomized controlled trials, all they ever did was test drugs or whether the conventional dietary wisdom did what they hoped, which was keep people alive longer than no diet advice at all.
Finally, though, the low-carb approach is starting to catch on in the diabetes world.
The ADA [American Diabetes Association] actually just published a pretty good nutrition committee assessment. The nutrition committee said that alternative diets can work, it’s just that low-carb is the best tested of the diets and the most consistent in showing positive effects.
But then, when they produced the new standard of care document … let me read to you exactly what it says:
“Most individuals with diabetes report a moderate intake of carbohydrate (44–46% of total calories). Efforts to modify habitual eating patterns are often unsuccessful in the long term; people generally go back to their usual macronutrient distribution. Thus, the recommended approach is to individualize meal plans to meet caloric goals with a macronutrient distribution that is more consistent with the individual’s usual intake to increase the likelihood for long-term maintenance.”
That’s crazy! Tell people to eat what they’ve always been eating, that way they’ll always follow your advice. Talk about having your priorities wrong.
You’ve been dealing with this type of thinking for your whole career, right?
Pretty much, but it’s just getting weirder and weirder.
I talked to one of the nutrition committee researchers about the standard of care document, and I said, “the nutrition committee says this and the standard of care says that,” and he just said, “they don’t have to follow our advice.”
How do you keep an eye out for bias and bad science in the keto world itself?
One of the problems is that the mainstream obesity research community has failed so miserably to solve this problem that it’s left up to the physicians and patients themselves to do it. You end up getting this world in which you have hundreds of diet books published every week and everyone has different variations on major themes, some of it’s right, some of it’s wrong, and there’s no way to tell. We have a scientific process that spews out, almost by its very nature, more wrong papers or wrong results than right. This has always been accepted as an unavoidable aspect of science – people are going to make mistakes – and it takes a long time to figure out what’s ultimately true and what’s not.
For the readers, my advice is basically don’t pay attention to the latest study or the latest take on keto or your diet of choice. What’s new is as likely to be wrong as right, or more likely. There are certain truths that you can hold onto, a lot of which have to do with how you feel. You can experiment on yourself to see what works and what doesn’t.
The keto world has elaborated on the central idea of restricting carbs – for example, with intermittent fasting or the carnivore diet. There’s a lot of good anecdotal evidence for these trends, but there’s also a mythology that grows up around these things faster than the science can support it.
I don’t know what to make of it. I intermittent fast – I don’t eat breakfast anymore. I tried it as an experiment and I liked the results. I felt better. I ended up losing a dozen pounds over the course of three or four months that I didn’t think I needed to lose. I kept it up because I felt better, I had more energy. I’m sharper in the morning if I don’t eat breakfast. So, bingo. Fine for me. Will I live longer because I don’t eat breakfast? I have no idea. Will it reduce my risk of heart attack? No idea. But I feel better.
I would try carnivore as an experiment – unfortunately my wife is a mostly vegetarian who doesn’t particularly like the way I eat anyway. I don’t think my marriage could sustain a one-month test of the carnivore diet, but I’d be curious to see how I felt if I didn’t eat any plant products. I know people who have tested it themselves, and we all know some people have stayed carnivore.
I do think these are all variations on a theme, which is minimizing insulin. After that, I don’t know. There are arguments for why plants might be toxic to some people, and I can imagine that that’s true on some level, just like I can imagine a lot of things are true on some level. I’m not sure how you would test it in any meaningful way scientifically, other than to try it yourself.
Do you have lingering doubts over the long-term health impacts of high fat diets?
Even if we did the randomized controlled trials … let’s say the trials take 10,000 people, you randomize 5k to a ketogenic diet and 5k to a Mediterranean diet. Let’s make it 15k so we can throw another 5k into a vegan diet. And if we learn that the ketogenic diet people live on average 1 year later, that’s still an average. For all we know, it might kill a third of the people a year earlier, and the other two-thirds live a few years longer. You just never know. I’ll always have lingering doubts. It’s in my nature.
Finally, if you were appointed the American diabetes czar, what would you change about the way we’re treating diabetes in the country?
I would do two things. First, I would lobby to get rigorous tests done, rigorous randomized controlled trials of these different dietary approaches. And I’d set the experiments up to make sure we get good compliance with the diet. We don’t want to know if somebody does some half-assed attempt at a diet, we want to know what happens if they follow the diet. If we spend half a billion dollars doing this, that’s about what diabetes costs the country in direct medical costs every half a day.
The second thing, even without the rigorous trials, is educate physicians so that they can support people on this low-carbohydrate dietary approach. Particularly patients with Type 1, who really need the support of their physicians.
What the world needs, and what I’m going to argue for in my book, is for people to know that this diet can be really beneficial. And that’s clear even without the randomized controlled trials. You see the type of blood sugar control Type 1’s get with very low carbohydrate diets and the Bernstein approach – it’s remarkable.
I want the physicians that treat diabetes patients to understand that, to educate themselves to guide and counsel their patients should they decide that what they want to try is a ketogenic diet.
But at the moment, it’s considered a fringe diet or a fad diet or a dangerous diet. You know, I interviewed a physician with T1D – a physician! – who was fired by his endocrinologist for going on Dr. Bernstein’s diet.
The conventional wisdom is that when you’ve got diabetes you should knock it off with the sugar and junk food. But my experience is that when you’re actually in the doctor’s office, they bend over backwards not to tell you that, because they’re worried that they’ll offend you or lose your trust.
The rationale, particularly with children, is that somehow it’s better for a child to not feel special than it is to accept that they’re special and work to be as special as possible, as healthy as possible, now that they’ve been dealt these bad cards. And I get it, each kid is different, it’s a delicate issue.
But the ADA has to communicate that this is a viable therapy, which the nutrition committee confirmed for them. And physicians owe it to themselves to learn about it. I would tell them to make the effort.