“We believe than an injustice is being perpetrated that has to be righted.”
Gary Taubes doesn’t mince words in his new book, The Case for Keto. The text is his clearest and most concise broadside against the “tragic preconceptions” that have plagued official dietary advice for so long, advice that has, in his telling, ultimately led to the twin epidemics of obesity and diabetes.
It is also a practical manual, a guide to low-carb lifestyle from a man who’s been living it for years, and has read more research on the subject, both past and present, than just about anyone else. The book is intended to be a “manifesto for this nutrition revolution.”
Taubes, an investigative journalist, has been on the low-carb beat for nearly two decades. He was once a comparative voice in the wilderness, one of the first prominent sources to call for a reevaluation of our understanding of dietary fats and carbohydrates. When Taubes last published a book explicitly on the subject of diet and obesity—2011’s Why We Get Fat—there was barely a “keto” movement to speak of. How things have changed!
Now, by Taubes’ own estimate, there are tens of thousands of doctors and dietitians in clinical practice that advise low-carbohydrate diets to their patients. Many have adopted such a diet themselves.
Different keto interpretations and sub-communities have grown up around the phenomenon that Taubes helped touch off, and as mainstream media and major food businesses glom onto the trend, it can become difficult to define what keto exactly is and what it’s supposed to do. The Case for Keto is Gary Taubes’ opportunity to consolidate his many years of work on the subject, and to put forth a definitive description of and argument for the very-low carbohydrate (“keto”) diet.
Hunger, Insulin, & Fat Accumulation
The very first words of the book proclaim that Taubes is “not writing this for the lean and healthy of the world.” The Case for Keto is built upon the assertion that there must be a fundamental physiological difference between lean people and those that struggle with their weight, a difference that has nothing at all to do with willpower. Taubes argues that lean people are, in essence, blessed with a metabolism that ensures they’ll stay lean. They’re just lucky that way.
Taubes believes that given the chance, every one of us, lean or thick, will eat until we satisfy our hunger. Fatter people aren’t more indulgent. Fatter people are just hungrier. Hunger explains almost everything. Self-restraint’s got nothing to do with it.
Why are some people just hungrier than others? Here’s how it works: those predisposed to overweight and obesity have bodies that try to accumulate fat “even when they’re half-starved.” The mechanism by which this would occur isn’t terribly complex: basically, consumed energy that should be used immediately instead gets unnecessarily packed into fat cells, leaving the individual feeling deprived and compelling him or her to overeat. From this perspective, gluttony doesn’t cause metabolic dysfunction, but the other way around.
For most of us, that dysfunction is triggered by high insulin levels. The body most reliably secretes insulin in response to dietary carbohydrates, especially sugar and refined starches.
Insulin’s effect on fat metabolism is, in essence, an on/off switch. You’re either burning fat or you’re adding fat, and there isn’t really anything in between. Diets succeed or fail, Taubes proposes—whether keto, vegan, low-fat or anything else—almost entirely due to how much time the dieter spends with fat accumulation set to “off.” So, here’s the case for keto in a nutshell: there is no sustainable diet that more effectively keeps fat accumulation off, and fat burning on.
The same mechanism explains the abject failure of mainstream diet advice, which invariably asks dieters to eat less than that they want to. Any diet that requires its eater to tolerate constant hunger is absolutely doomed to failure. We just can’t do it. The only diet that can succeed long-term is one that allows an eater to achieve a caloric deficit without feeling hungry. Keto is the one diet that has been repeatedly validated to do just this. By keeping insulin low and fat accumulation off, keto eliminates the hunger that drives us to overeat.
Taubes isn’t, by any means, the first person to think these thoughts, and one of his delights is in uncovering important figures in the past that got the story right. For example, the influential Harvard nutritionist Jean Mayer once said: “To attribute obesity to ‘overeating’ is as meaningful as to account for alcoholism by ascribing it to ‘overdrinking.’” Here is Columbia University’s Hilde Bruch: “overeating … is not the cause of obesity; it is a symptom of the underlying disturbance.”
These clarion and insightful assesments from the past are thrilling to read, and help convince that keto is less a modern fad than something we could and should have known about all along. But it never quite caught on.
For one thing, experiments with very low-carb diets in the early and mid-20th century were so astoundingly successful, Taubes writes—granting both weight loss and a “remarkable absence of complaints of hunger”—that researchers could be hesitant to share their results, or felt compelled to water down their claims.
At the same time, there was a growing nervousness about the long-term health impact of high-fat eating patterns. Prominent mid-century researchers, notably Ancel Keys, blamed saturated fat consumption for heart disease risk; this view would soon dominate nutrition thinking, and for decades brought research into low-carb diets to a near standstill. Even those doctors in the meantime that discovered how effective very-low carbohydrate diets could be usually wouldn’t recommend them as long-term choices.
The Case for Keto
All that is beginning to change, thanks in no small measure to Taubes’ own earlier work on the subject. Keto now seems increasingly like a viable lifelong eating strategy. One of the most significant changes over the last two decades—since the author himself first effortlessly lost 25 pounds on the Atkins diet—is the number of experts that have endorsed the low-carb, high-fat diet as a healthy long-term lifestyle. Taubes now reports that he has spoken to over a hundred physicians, both in research and clinical practice, that “believe these diets are inherently healthy, perhaps the healthiest way for many if not most of us to eat.”
Should we be concerned about the health impacts of heavy fat consumption? While it’s common in keto circles to exclaim that early hunter-gatherers or the Inuit “prove” that keto is a healthy lifestyle, Taubes rightly considers this speculation, not proof. We don’t know definitively if the risks of a keto diet outweigh the benefits, and it’s possible that we will never know. The rigorous experiments we would need to answer the question might be practically impossible to conduct. “But it’s hard to imagine that a way of eating that makes people so much healthier in the short run … will harm us in the long run.” It’s a gamble, he says, but a gamble that “we have to take.”
Ultimately, no matter what the biochemical justification, a diet only works if it works. Taubes’ advice is to trust your body: “It doesn’t matter what clinical trials conclude. What matters is what happens to you.”
The final chapters of the book offer a primer for those ready to try the diet themselves. Taubes’ introduction to the eating pattern is straightforward and clear. This section flows very naturally from the scientific explanations and historical context, giving the reader a very solid understanding of both the why and the how of the ketogenic diet.
What can you eat? What can’t you? Can you eat berries? Can you overeat protein? There are many books with this sort of information, but Taubes’ take is distinctive, informed by his long personal experience on the regimen, his incisive reading of the relevant scientific papers, and his relationships with the many doctors and other experts putting keto into practice around the world. His writing is clear, his treatment is approachable, his advice easily actionable.
This single volume manifesto mounts the strongest possible case in favor of the very-low carbohydrate ketogenic diet, especially for readers with weight to lose, and those for whom other diets have just never worked.