In Defense of Food: My Review

July 24, 2012 at 7:42 am · Filed under In Defense of Food, Science ·Tagged diet, food, In Defense of Food, Michael Pollan, nutrition

Michael Pollan’s In Defense of Food might best be described as a book which fares best when judged by its cover. Below the title, a reader finds some dietary advice which is not a bad place to start: “Eat food. Not too much. Mostly plants.” There are a few good ideas inside the book, too. It would be easy not to look much deeper, as Pollan’s prose is so lively that most readers won’t want to stop and give things a closer look. However, the reader who does bother to check the details sees that In Defense of Food is not a credible work of nonfiction. Pollan twists facts and misrepresents the way science works in the course of assembling exaggerated, false, and contradictory narratives.

Pollan’s central thesis is that introducing science into our food system has done more harm than good and that the best thing for all of us would be to go back to eating a more traditional diet. It’s fair to point out that nutritional science has led to some mistakes (such as recommendations to replace saturated fats with hydrogenated oils), but Pollan devotes too much of his effort to dismantling his own shallow caricature of science. Pollan’s chief criticism of nutritional science is that it adheres to the ideology of nutritionism, which he defines as the belief that foods can be understood by studying their constituent nutrients. He explains that nutritionism is rooted in the idea that foods are “decidedly unscientific things” (19) and that studying individual nutrients is “the only thing [nutritional scientists] can do” (62). He even puts forth the idea that the goal of nutritional science is to find an “X factor” (178) — a single compound that is responsible for good health — so that food processors can add more of it to their products.

But science — to the people who study it — isn’t defined by the consideration of certain “scientific” things with hard-to-pronounce names. The scientific method is a general process for improving our understanding of the world. It entails using observations to form a hypothesis, testing the hypothesis experimentally, and refining that hypothesis based on the results of the experiment. As far as the scientific method is concerned, oranges are as good a subject to study as vitamin C. And nutritional scientists tend to be aware that human nutrition is too complicated to be explained by a single “X factor.” After all, that’s part of what makes their jobs challenging!

As proof of the malignancy of nutritionism, Pollan points to the various sets of nutritional guidelines which encouraged Americans to reduce their fat consumption. As Pollan explains, these recommendations gave rise to products like the SnackWell’s cookie, which was presumed healthy on the basis of its being fat-free. He contrasts the low-fat guidelines with the theory (put forward by Gary Taubes and others) that weight gain results when the consumption of refined carbohydrates promotes fat storage and overeating. If that theory is correct, he explains, “there is no escaping the conclusion that the [official dietary advice] bears direct responsibility for creating the public health crisis that now confronts us” (59-60).

By the end of the book, he’s moved on to blaming that same public health crisis on overconsumption of cheap sweeteners and added fats, pointing out that Americans have added 300 calories to their daily diets since 1980 and citing a group of Harvard economists who “concluded that the widespread availability of cheap convenience foods could explain most of the twelve-pound increase in the weight of the average American since the early 1960s” (186-187). If both the dietary guidelines and the cheap convenience foods are to blame, then it must be that the guidelines encouraged Americans to eat those convenience foods, right?

Not exactly, as it would happen. For all his insistence that Americans have “an unhealthy obsession with healthy eating” (9), Pollan gives us precious little evidence that we’ve actually been following the official dietary advice. Indeed, a reader of the various guidelines would see that falling prey to the food marketers often meant going against the science-based dietary advice. For instance, the second edition of the 1977 Dietary Goals for the United States, one of the main sets of guidelines which Pollan criticizes, included warnings against overeating and recommended a decrease in consumption of both fats and refined sugars. So while the sugary SnackWell’s cookies might have helped to reduce fat intake, the dietary guidelines were hardly an invitation to eat them without restraint.

It should thus be no surprise that in his quest to fault science-based nutritional advice for our public health crisis, Pollan often misleads readers about what the dietary guidelines actually said. He tells us, for instance, that a literature review “found ‘some evidence’ that replacing fats in the diet with carbohydrates (as official dietary advice has urged us to do since the 1970s) will lead to weight gain” (45). It sounds pretty damning, at least until you look at the actual paper, which, in fact, reported “some evidence” that replacing dietary fats with refined carbohydrates leads to weight gain. Pollan, of course, had a very good reason to leave out the extra word: that little bit in parentheses would have been false if he’d included it. The government recommendations never urged Americans to replace dietary fats with refined carbohydrates. Truth be told, the official dietary advice could have done better here, but a reader of the recommendations would see encouragements to decrease our consumption of a major class of refined carbohydrate (sugars) and to eat more unrefined carbohydrates in the form of fruits, vegetables, and whole grains.

But some falsehoods can’t be made to look true just by neatly hiding the pesky details behind a missing adjective, and Pollan’s book contains some of these ideas, too. Indeed, the notion that nutritional scientists study nutrients to the exclusion of foods is incorrect; the ideology of nutritionism that occupies so much of Pollan’s attention is a straw man. A reader might get the sense that something isn’t quite right when Pollan refers to a few nutritional studies that considered whole foods. On the other hand, the reader might suppose, perhaps those studies are outliers. After all, Pollan tells us that (since 1977) the official dietary recommendations have always been expressed in terms of nutrients rather than foods. As an example, he gives us the 1982 report, Diet, Nutrition, and Cancer, in which the National Academy of Sciences “was careful to frame its recommendations nutrient by nutrient rather than food by food, to avoid offending any powerful interests” (25). The only problem is that it isn’t true. The report contains six “Interim Dietary Guidelines,” only one of which was expressed in terms of nutrients, and two of which were expressed in terms of foods. (Of the remaining three, two were encouragements to keep dangerous substances out of the food supply, and one was a reminder not to drink too much.)

The antidote to nutritionism, as Pollan explains, is “to entertain seriously the proposition that processed foods of any kind are a big part of the problem” (141) and  “escape the Western diet” (142) for a more traditional diet. That’s a bold declaration, considering that “processing” in the food system includes not just things like hydrogenating vegetable oils but also everything from chopping vegetables to slaughtering animals. Pollan reasons that science has made us unhealthy by encouraging us to eat in new ways, but a traditional diet must be healthy because “if it wasn’t a healthy regimen, the diet and the people who followed it wouldn’t still be around” (173). Unfortunately, he thereby misses the rather important point that a diet can be unhealthy without doing away with its eaters. Pollan’s line of argument would, for example, vindicate the diet of white rice that left so many with beriberi. And some day, it may well exonerate the American diet, whose worst health effects tend to show up well beyond reproductive age.

For all that Pollan gets wrong, there is a grain of truth to his message. Though Pollan errs in faulting nutritional science for giving us a license to eat every high-carb, low-fat food that processors might concoct, it is true that it would be a bad idea to assume that a low-fat food is a healthy food. Pollan is probably even right that some people reached that conclusion based on their interpretations of the official dietary advice. However, the lesson to take away from this is not that we should ignore nutritional science but that when we oversimplify our decision-making processes, we leave ourselves particularly vulnerable to cheap marketing ploys. With that in mind, the solution he offers is regrettable. Rather than embracing critical thinking and careful attention to detail, Pollan gives us a few simple rules backed up by the same sort of lazy thinking that he claims to have seen in nutritional science. It should therefore be no surprise that food companies have begun to take advantage of his rules for eating, with Frito-Lay advertising that its Lay’s potato chips have only “three simple ingredients” (less than Pollan’s recommended maximum of five ingredients) and manufacturers reformulating products like Gatorade, Hunt’s ketchup, and Wheat Thins to replace the taboo high-fructose corn syrup with other sugars.

To be fair, a few of Pollan’s rules, such as “eat slowly…in the sense of deliberate and knowledgeable eating promoted by Slow Food” (194) and “plant a garden” (197), will probably prove difficult for food companies to use for their own ends. For the most part, however, these reflect a level of privilege which many people do not have. This isn’t too surprising, as Pollan makes no secret of the fact that he writes for a well-to-do audience when he declares, “Not everyone can afford to eat high-quality food in America, and that is shameful; however, those of us who can, should” (184). That doesn’t invalidate his perspective, but there is nonetheless something a bit distasteful about a bestselling author lamenting the eating habits of people whose lives are worlds away from his own. Absent any indication of a good-faith effort to understand why people might choose to microwave frozen dinners instead of preparing a family meal from home-grown ingredients, Pollan’s work seems less likely to inspire positive social change than, as Julie Guthman puts it, to appeal to “those who already are refined eaters and want to feel ethically good about it.”

Michael Pollan remarks in the introduction of In Defense of Food that had he written the book forty years earlier, it would have been received as “the manifesto of a crackpot” (14). In light of the superficiality of the book’s merits and its loose relationship to the facts, that wouldn’t have been a particularly unfair appraisal. Alas, in the time since the work’s publication in 2008, our collective judgment has proven decidedly less sound. Thanks to its engaging style and appealing commonsense message, In Defense of Food has become required reading for thousands of college students, and its author now stands at the helm of a respected social movement. With the alarming rise in diet-related disease, the time was indeed ripe for someone to fill that leading role. It’s just too bad that it was somebody who mostly gives us the same kind of simplistic solutions and sloppy reasoning that helped to create the problem in the first place.

Also posted at Amazon and Goodreads. For more on In Defense of Food, I recommend the following posts:

• Michael Pollan and John Harvey Kellog
• Should Americans be spending more on food?
• Michael Pollan, X factors, and Weston Price
• Mike Gibney critiques In Defense of Food

You can also look at all of my posts about In Defense of Food.

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