Last September, the Annals of Internal Medicine published a remarkable study on the comparative health benefits of low-fat versus low-carbohydrate diets. Conducted at Tulane University with funding from the National Institutes of Health, the study followed a racially diverse group of 148 men and women ranging in age from their early twenties to their mid-seventies. All were obese but otherwise in good health. Half were randomly assigned to follow a low-carbohydrate regimen, the other half a low-fat one, all with no calorie restrictions and no changes in activity levels. The low-fat group ate more grains, cereals, and starches and cut their total fat intake to less than 30 percent of their daily calories, in line with the federal government’s dietary guidelines. The other group raised their total fat intake to more than 40 percent of daily calories, including getting 13 percent of their calories from saturated fat, more than double the amount recommended by the American Heart Association (AHA).
The Big Fat Surprise:
Why Butter, Meat, and Cheese
Belong in a Healthy Diet
by Nina Teicholz
Simon & Schuster, 479 pp.
After a year, both groups had lost weight. But those on the high-fat diets had dropped three times as much. The higher-fat group had also lost weight in a healthier way, reducing body fat, whereas those on the low-fat diet lost mostly lean muscle mass. Finally, the high-fat, low-carb eaters did better at lowering their risk factors for heart disease. “In the end, people in the low-carbohydrate group saw markers of inflammation and triglycerides—a type of fat that circulates in the blood—plunge,” reported the New York Times, while “[t]heir HDL, the so-called good cholesterol, rose more sharply than it did for people in the low-fat group.”
These findings, needless to say, run exactly counter to the nutritional advice Americans have been given for decades—that fat, especially saturated fat, is unhealthy, a broadener of waistlines and a clogger of arteries. If it were just this one study, the findings could perhaps be dismissed. In fact, it was the latest in a long line of similar research going back years. Six months earlier, the Annals of Internal Medicine published a meta-analysis of twenty-seven clinical trials that found, according to the Boston Globe, “no difference in heart disease rates among those who had the least amount of saturated fat compared to those who consumed the most.” A meta-analysis of twenty-one other studies, published in the American Journal of Clinical Nutrition in 2010, found “no significant evidence for concluding that dietary saturated fat is associated with an increased risk of coronary heart disease or cardiovascular disease.”
Anybody who’s been reading the papers carefully for the last decade has probably picked up on this news, which may explain the recent popularity of low-carb and “paleo” diets and the growing presence of bacon and pork belly on the menus of trendy restaurants where the educated congregate. But the news has yet to reach the average Joe. A Gallup poll last July showed that twice as many Americans are trying to avoid fats as carbs.
These folks are still following the anti-fat advice drummed into them over the years by government and medical experts, especially the AHA and the federal government’s “Dietary Guidelines for Americans,” jointly published every five years by the U.S. Department of Agriculture (USDA) and the Department of Health and Human Services (HHS). Yet instead of backing off the message about the dangers of saturated fat, the AHA has held fast to its position, and the USDA, in its most recent guidelines, lowered its recommended daily consumption of such fat.
These recommendations have led, in turn, to new regulations on school lunch programs. But parents and school lunchroom employees complain that the students won’t eat the new, supposedly healthier food. Most kids, for instance, skip over the skim white milk in favor of low-fat, heavily sweetened chocolate stuff. And, as researchers at the University of Virginia have found—you guessed it—kids who drink low-fat milk are much more likely to be overweight than those who stick to whole milk.
At some point soon, the majority of Americans are going to realize that they’ve been had—that the dire warnings about saturated fat they’ve been hearing from health experts and the government, which they have dutifully been trying to work into their daily eating routines, were flat-out wrong, and may have actually been doing them harm. When we reach that point, two things will happen. First, a collective cheer will go up across the land upon the news that it’s okay to eat cheeseburgers. Second, the public’s growing (if lamentable) distrust of scientific and government experts—be they climate scientists or Centers for Disease Control (CDC) officials—will kick into overdrive.
How official nutritionists and the government blew the call on fat is therefore a hugely important issue. It is also the subject of a remarkable new book, The Big Fat Surprise: Why Butter, Meat, and Cheese Belong in a Healthy Diet, by former Gourmet magazine and National Public Radio reporter Nina Teicholz. While the title suggests a mass-market diet book, it is far more than that. Building on journalist Gary Taube’s work, Teicholz (who has also written for this magazine) spent nearly a decade combing through tens of thousands of scientific studies and documents and interviewing scores of key scientists, bureaucrats, and industry insiders, many of them in their eighties and nineties. Her attributions and bibliography alone run 115 pages.
The result is a fascinating, detailed, and highly readable investigative history of how some of America’s most trusted scientific institutions went off the rails. The tale involves a small group of ambitious and influential scientists, a credulous media, crusading politicians, a public desperate for easy answers to complex questions, and the largely hidden hand of industry. It is, in short, a very Washington story.
As early as the late nineteenth century, some researchers were beginning to wonder if animal fats, in particular the cholesterol in such fats, might be responsible for heart disease, since cholesterol is a major component of atherosclerotic plaque. The idea slowly gained ground among some researchers in the 1930s and ’40s as the rate of heart attacks among adult males grew. It had—and continues to have—a certain commonsense plausibility. Since plaque clogs arteries “like hot grease down a cold drain,” in Teicholz’s vivid phrase, and stops blood flow, triggering heart attacks, eating more of the stuff plaque is made of must increase the risk of heart disease. But this was by no means the consensus among researchers and nutritionists, most of whom were publishing and publicizing studies on how children raised on a diet rich in meat, eggs, and dairy products grew taller and stronger than those who weren’t.
About the same time, a fundamental change in the American diet was under way, one Teicholz considers especially deleterious: the increasing use of vegetable oils from corn, soybeans, rapeseed, and cottonseeds. For most of human history, vegetable oils were not used for cooking, for the simple reason that (with the exception of olive oil) they turned rancid quickly at room temperature. As recently as 1910, American housewives cooked almost exclusively with butter and animal fat. Vegetable oil was used largely to make soaps, tallow, lubricants, and resins; it was barely considered edible.
Then, in 1911, Procter & Gamble patented the process of hydrogenating vegetable oil—that is, adding hydrogen atoms to the lipid molecule, which allowed the oil to be stored at room temperature without going bad. The first big commercial application of this innovation was the creation of Crisco, which stayed firm and fresh at room temperature, just like lard or butter. As Americans would later learn, some eighty-plus years later, hydrogenated vegetable oil is full of “trans fats,” which increase the risk of heart disease by lowering HDL levels in the blood while raising those of LDL, or “bad” cholesterol. But at the time, the processed food industry successfully promoted vegetable oil as “easier to digest” and a more up-to-date, modern alternative to the meat- and dairy-based fats Grandmother used. Consumption of such products, and of processed food containing them, like cookies and pastries, soared.
Eager to promote their products’ health benefits, in 1941 big food manufacturers like Quaker Oats and the Corn Products Refining Corporation created something called the Nutrition Foundation. The new organization, writes Teicholz, “steered the course of science at its very source by developing relationships with academic researchers, funding important scientific conferences, and funneling millions of dollars into research.” In 1948, Procter & Gamble took that strategy a step further: it donated all the profits from its popular Truth or Consequences radio program to the American Heart Association, then a small, underfunded organization founded in 1924 by cardiologists seeking to understand the growing problem of heart disease. (With further contributions from other food giants, the AHA would grow into a behemoth, with a $30 million budget by 1960, making it the largest non-profit in the country at the time.)
That same year, 1948, the AHA successfully lobbied President Harry Truman to create the National Heart Institute—now the National Heart, Lung, and Blood Institute (NHLBI)—within the National Institutes of Health (NIH). Truman then appointed AHA founder Paul Dudley White to run the new agency, thereby ensuring, Teicholz suggests, that the AHA and its industry backers had influence over the doling out of NIH research grants.
At around this point in Teicholz’s tale, a second villain—after the vegetable oil industry—enters the picture. He is Dr. Ancel Benjamin Keys, a pathologist with advanced degrees in biology and physiology who worked at the University of Minnesota. Brilliant and charismatic, with a crusading streak and a knack for networking, Keys had managed during World War II to get himself appointed as an adviser to the secretary of defense, a post from which he developed meals for the U.S. Army called K Rations—the “K” stood for “Keys.” By the early 1950s, Keys had become convinced that the consumption of animal-based fat was the key cause of heart disease.
He introduced his thesis, later dubbed the “diet-heart hypothesis,” in a 1953 paper that purportedly showed a close correlation between fat intake and death rates from heart disease in six countries. The paper generated tremendous buzz, and Keys expected to make a big splash when he presented it at a World Health Organization conference in Geneva. He did—just not quite the way he had anticipated. Jacob Yerushalmy, professor of biostatics at the University of California, Berkeley, pointed out that Keys had chosen to study only countries that would support his thesis. He didn’t account for countries like West Germany, Switzerland, Denmark, and, of course, France—where the consumption of diets high in saturated fats did not translate to ill heart health. Keys was humiliated and furious. When Yerushalmy and a colleague presented a paper showing data from twenty-two countries that suggested other factors, such as the number of cars and cigarettes sold, or the amount of sugars and protein consumed, might have a role to play, Keys responded by “devoting several pages to attacking theories that competed with his own” without offering a rebuttal of the hypothesis under review.
While Keys’s extreme self-assurance rankled colleagues, there was a market for it at the time. In the early 1950s, America was in the grip of what looked to be an epidemic of heart disease, with alarming numbers of middle-aged men succumbing to the disease. When President Dwight Eisenhower had a heart attack in 1955, there was panic across America. The public was hungry for definitive answers, and Keys believed he had them. (That Ike’s previous four-pack-a-day smoking habit might have had something to do with his heart disease was not widely discussed.)
Keys also had connections: Paul Dudley White had by then become Ike’s personal physician and was a personal friend of Keys’s. White enjoyed nearly “boundless influence” in his field and regularly took to the airwaves to update the American public on Eisenhower’s health. When invited to write in a front-page piece in the New York Times, the only researcher White mentioned by name was Ancel Keys. (Once he recovered, the president became a fervent adherent to the low-fat way, giving up butter for margarine and eating Melba toast for breakfast every day until his death, from heart disease, in 1969.)
Even within the AHA, however, there were serious doubts about the supposed links between saturated fats and heart disease. In the late 1950s an AHA committee of nutrition experts openly criticized diet-heart advocates like Keys for taking “uncompromising stands based on evidence that does not stand up under critical examination.” Keys responded in 1961 by getting himself and an ally appointed to the AHA nutrition committee. After that, the AHA swung around, announcing to the world that “the best scientific evidence” suggested that people at risk of heart attacks and strokes cut the amount of saturated fats and cholesterol in their diets. Two weeks later, Time magazine put Keys on the cover, guaranteeing him international celebrity status and effectively endorsing his views.
To advance his hypothesis, Keys launched one of the most ambitious epidemiological studies ever done. In the “Seven Countries Study,” he examined the diets in Yugoslavia, Greece, Italy, the Netherlands, Japan, Finland, and the United States. The results, the first of which were published in 1970, seemed to support Keys’s views. Finnish lumberjacks, for instance, who ate a diet heavy in meat and dairy, died from heart attacks at far higher rates than Greek farmers in Crete, whose diet of grains, fruit, and fish was far lower in saturated fats.
There were many issues with the Seven Countries Study, however. In the late 1950s and early ’60s, when Keys was conducting his survey, Greece was still emerging from the deprivations of World War II and the Greek civil war. As children and young adults in the prewar years, these farmers had eaten diets heavy in lamb and other fatty foods, one of many confounding factors Keys ignored. Diving deep into the study, Teicholz also discovered an astonishing methodological weakness: one of Keys’s three surveys of Crete was conducted during Lent, when Orthodox Christians fast from all animal products.
Throughout the 1960s and ’70s, Keys’s diet-heart hypothesis gained adherents and support in the media, but had not been officially endorsed by the U.S. government. That began to change in 1977, when the Senate Select Committee on Nutrition and Human Needs, led by Senator George McGovern of South Dakota, held hearings on the links between certain foods and heart disease.
After the hearings, it fell to a McGovern staffer named Nick Mottern to research and write a report with dietary recommendations for the public. A former labor beat reporter and a “conscientious progressive,” Mottern had a jaundiced view of corporate power, especially the National Cattlemen’s Association, whose arrogant lobbyists regularly strode through the South Dakota senator’s offices. Mottern had no background in science or nutrition, however, so he turned for guidance to a Harvard nutrition professor and devotee of Keys’s diet-heart hypothesis, Mark Hegsted (Keys had by then retired).
The report Mottern and Hegsted produced, Dietary Goals for the United States, recommended lowering overall fat calories from 40 percent to 30 percent and saturated fats to 10 percent. In Mottern’s eyes, writes Teicholz, he was fighting a battle that “pitched the virtuous, AHA-endorsed low-fat diet against the debased meat and dairy industries.” He was, by all appearances, ignorant of the fact that much of the research he relied on had been quietly paid for by the vegetable oil and processed foods industries.
There was a furious backlash to the report from the meat, egg, and dairy industries and their backers in Congress, as might have been expected. But a large number of experts still remained unpersuaded. This complicated the task of translating the Dietary Goals report into federal guidelines, a job that fell to the newly appointed nutrition division director of the USDA. That person happened to be—surprise, surprise—Mark Hegsted. So to garner greater support, Hegsted decided to let his USDA recommendations be guided by a task force set up by the esteemed American Society for Nutrition.
Unfortunately for Hegsted, the task force wound up concluding two things: that the link between fat consumption and heart disease was a tenuous one, and that “the evidence condemning saturated fat was not persuasive,” writes Teicholz. The main problem, the task force explained, was that nearly all the evidence supporting the diet-heart hypothesis had come from observational studies of populations. Such “epidemiological” studies can establish correlation but, because they don’t control for different variables, not causation. For that, clinical trials are needed. But virtually no clinical trials on the diet-heart link had yet been done.
Still, the task force did not affirmatively say that reducing dietary saturated fat would cause harm. Hegsted took that as a green light to proceed, on a tenuous “better safe than sorry” logic. Hegsted’s Dietary Guidelines for Americans formed the basis of the USDA’s subsequent “Food Pyramids.” “Despite having grown from the work of a single congressional staffer and his single academic advisor and despite the lack of endorsement from nutrition experts,” writes Teicholz, “these are now the most broadly recognized food guidelines in the United States.”
One last battle remained to be fought. In a rearguard action, the highly respected Food and Nutrition Board of the National Academy of Sciences reviewed all the same studies everyone else had on the diet-heart hypothesis, and concluded that the studies had “generally unimpressive results.” This should have been a devastating blow. But by then the narrative in Washington was set: saturated fat was bad for you. The New York Times editorial page in essence accused the National Academy of Sciences of being biased, a view it further highlighted with a front-page investigative story in 1980 showing that two members of the academy’s Nutrition Board had done consulting work for the meat, egg, and dairy industries. The fact that two other members of the board were employees of food-processing companies was ignored. So too was the fact that the Nutrition Board had enough integrity to issue findings that ran counter to the interests of one of its own funders, the Nutrition Foundation, which was backed by vegetable oil and other food companies. In the eyes of respectable liberal opinion, anyone who questioned the view that saturated fat was a danger was either unenlightened or a stooge of the meat lobby.
Once government put its official stamp of approval on the diet-heart hypothesis, the American public dutifully complied, cutting its intake of saturated fats and shifting to the “low-fat,” carbohydrate-rich alternatives with which the processed food industry helpfully stocked the nation’s supermarkets. At about the same time, obesity levels skyrocketed, which Teicholz sees as no coincidence. Academics who continued questioning the anti-saturated-fat consensus became professional outcasts. Their funding dried up. Invitations to conferences no longer arrived. Journals would no longer publish their work.
Meanwhile, beginning in the 1980s, results from the first clinical trials on the health effects of saturated fat started coming in. One after another failed to show that lower-fat diets lead to lower levels of heart disease. Yet the anti-fat consensus held firm. Experts explained away the disappointing results as anomalous, or questioned the studies’ methodologies, or awaited the results of the next big clinical trial, which would surely prove them right.
Then, beginning in 1990, studies of a different sort started coming in. These documented the health dangers of trans fat. The vegetable oil and processed food industries spent millions trying to counter the studies, but more kept coming. Consumer advocates, who had earlier allied with the vegetable oil and processed food industries in attacking saturated fats, now turned on their former industry partners and led the charge against trans fat.
By 2006, the game was up when FDA began requiring all food labels to list trans fat amounts, effectively forcing food companies to remove trans fat from their products. But without trans fat, the companies were left without a solid fat option to use in their cookies, crackers, chips, and frozen food. They couldn’t very well go back to using more saturated fats, because the public was already in the habit of scanning food labels for them. So in recent years, the vegetable oil companies have been experimenting with oil made from a process called “interesterfication,” which, Teicholz reports, produces various triglycerides with unknown health effects. Meanwhile, fast-food restaurants have been reduced to frying with unprocessed vegetable oils that release chemicals like formaldehyde into the air.
The obvious solution, says Teicholz, is for the government to own up to its mistakes and start telling Americans that it’s safe to eat saturated fats. It is hard not to conclude that she is right. The opportunity, at least, for the government to correct the record may be at hand: the USDA/HHS new Dietary Guidelines for 2015 are currently being formulated and should be out soon.
Some of the media coverage that has greeted The Big Fat Surprise has described the book as an indictment of science. But that is not really the story Teicholz tells. Rather, as her book shows, time and again a consensus of scientists called it right, insisting that the weight of the evidence was insufficient to support the anti-saturated-fat position. What really happened is that, over the course of several decades, a relatively small network of zealous, well-connected, enterprising scientists, working with well-funded industry partners, managed to take control of key scientific institutions inside and outside of government. That gave them the power to roll the scientific consensus. The media and political leaders who went along were, for the most part, too ignorant of the underlying power dynamics to understand that they were being played. And that, unfortunately, is pretty typical of how Washington works to this day.