Recently I came across a new book called The Microbiome Diet. It is based on the idea that the colonies of bacteria in our guts are “the secret to healthy weight loss and to feeling healthy, energized, optimistic, and at the top of [our] game.” Author Raphael Kellman prescribes a three-phase plan that entails including prebiotic and probiotic “superfoods” such as yogurt, sauerkraut, garlic, and tomatoes in every meal.
Like most inventors of new diets, Kellman argues that his diet is needed because existing diets are based on bad information and consequently don’t work. He writes, “I believe that this book will challenge everything you know about the causes of obesity—and about the kind of diet that can successfully overcome it.”
It’s easy to laugh at Kellman’s suggestion that his diet is the only true solution to the problem of diet-related health problems. Only a few hundred people in the entire world are currently following it and it’s unlikely that more than a few thousand ever will. The notion that the only diet that’s truly good enough for humans would come along for the first time in 2014 and then pass into oblivion having made barely a ripple seems far fetched. But what about some of the other new diets, the ones that have caught on in a big way, such as the Paleo diet and the gluten-free diet and the high-fat version of the low-carb diet? The creators of each of these diets has also argued that his is needed because no previously existing diet was good enough to yield optimal health. Is any of these diets really needed? No.
What allows the creators of such diets to convince many people that a new way of eating is needed is the fact that the incidence of diet-related chronic diseases is higher than it’s ever been. This is clear proof, they say, that existing diets don’t work. Except it isn’t. For if all currently existing diets were ineffective in producing good health, then everyone would be unhealthy. But while most American adults are fat and doomed to die from heart disease, diabetes, or another disease affected by diet (Alzheimer’s, some cancers), in absolute numbers there are lots of healthy people. Indeed, virtually everyone who actually makes an honest effort to eat healthy by any definition and sustains this effort throughout life is rewarded with robust health. The people who end up fat and saddled with chronic disease are the majority that doesn’t even try to eat healthy.
If we look at the small sliver of the population that sustains its efforts to eat healthy, we find that many existing diets work perfectly well. People who start and stay on sensible versions of vegetarian, Mediterranean, low-carb, low-fat, clean-eating, locavorian, agnostic, and other diets are typically hale and hearty. The problem is not, as the inventors of new diets assert, that there are no good options. The problem is that only a tiny fraction of us takes advantage of the many good options available to us.
Here’s another way to look at it: In 1950, virtually no one was following anything we would recognize as a microbiome diet or a gluten-free diet or a Paleo diet or a high-fat/low-carb (HFLC) diet because A) these diets hadn’t been invented yet and B) they are not culturally normal, so it was unlikely that some random weirdo would eat by the rules of any of them accidentally. Thus, to argue that any of these new diets is needed because no previously existing diet was good enough is essentially to argue that no one living in 1950 was healthy.
Of course, advocates of the Paleo diet argue that their way of eating is not new at all but a reversion to “the original human diet,” and some proponents of the HFLC diet do the same. This argument represents a complete inversion of the truth. Paleo dieters eat the same modern foods that everyone else eats, all of which are only distantly related to the foods eaten by Paleolithic humans. The only difference between the way the average Paleo dieter eats and the way his next door neighbor eats is that the Paleo dieter eschews some foods, such as dairy, that his neighbor eats. This combination of modern foods and selective exclusions is fundamentally novel. When Loren Cordain published The Paleo Diet in 2002, the eating program unveiled therein was the world’s newest diet. If it resembled primitive diets more than other modern diets did, it was only on the most superficial level.
In any case, a more important way in which Paleo diet doctrine stretches credulity is the same way that most other new diets do. According to Paleo doctrine, humans stopped eating right at the dawn of the agricultural revolution some 12,000 years ago. Therefore, to argue that the Paleo diet is needed because no post-Paleolithic diet was good enough to support optimal health is essentially to argue that there have been no healthy humans for the past 12 millennia.
Let me be clear: I’m not suggesting that all new diets are bad. I think most of them are good. Humans can thrive on a wide range of diets, so it’s not hard to come up with a novel diet that respects the few nutritional laws that can’t be broken without repercussions for health. But no new diets are needed. The current epidemic of diet-related diseases will not be solved by the discovery of the first and only diet that really works. Good-enough diets have always been available. Until scientists invent a pill that makes people crave broccoli and gag at the sight of french fries, each of us is on his own to solve the problem individually by selecting one of the many good-enough diets and sticking with it.