In the great morality play of modern diet, the angels, we have been told by a host of experts, favor egg-white omelets and skimmed milk, while the devil gorges on red meat cooked in butter. For 50 years we have been warned to fight the good fight on dietary fats if we want to stay healthy. In "The Big Fat Surprise," as one might guess from the title, Nina Teicholz plays the devil's advocate—convincingly.
The road to dietary hell, she notes, was paved in the 1950s by a series of seemingly related phenomena. An epidemic of heart attacks fell upon apparently healthy middle-aged men, including President Dwight Eisenhower, who brought national attention to the problem. They all had high levels of cholesterol, thought to be the critical component of the arterial plaques that clogged arteries, restricted blood flow and triggered heart attacks. The cholesterol was coming from an abundance of meat, eggs, butter and cheese—foods that had all been rationed during the war.
The connection between a diet rich in saturated fats and cardiovascular disease was made by Ancel Keys, an American physiologist who, when visiting Italy and Spain in 1953, concluded that heart-disease rates among men there were low because they ate very little meat and dairy. It was a hypothesis that turned into a juggernaut of censure, not least because Congress was full of middle-aged men chomping down on red meat and eggs. "Eisenhower," notes Ms. Teicholz, "became obsessed with his blood cholesterol levels and religiously avoided foods with saturated fat." That his earlier four-pack-a-day cigarette habit might have had something to do with his coronary disease didn't seem to occur to anyone.
Eisenhower's personal doctor and America's most prominent cardiologist, Paul Dudley White, whom Keys had assiduously cultivated, described Keys's work as "brilliant" in a front-page New York Times article. Keys became a media oracle, dispensing, as Ms. Teicholz puts it, "fiery language and [a] definitive-sounding solution" to America's new health problem. When the American Heart Association embraced his message, it was game over.
But, as Ms. Teicholz observes, there was a paradox in the statistical data. At the time, the Swiss ate a lot of animal fat; so too, the Swedes, the Norwegians, the Danes and the Germans. But there was no correlation with rates of heart disease. Why, Keys's critics asked, was he ignoring this data? In 1956, armed with a massive U.S. government grant, Keys embarked on "the first multicountry epidemiological undertaking in human history" to prove his hypothesis—the "Seven Countries study," as it came to be called. Critically, and appallingly, he excluded the "paradox" countries.
Ms. Teicholz, who has a gift for translating complex data into an engaging forensic narrative, explains why the "proof" that the Seven Countries study seemed to deliver was far from conclusive. One morsel: Keys had included data on the Greek diet taken during a 48-day Lenten fast in Crete, when participants were required to abstain from meat, fish, eggs, cheese and butter. Forty years later, researchers estimated that 60% of the Cretan population had been fasting at the time of the study, but no attempt had been made to separate fasters from non-fasters.
Yet when skeptics, including the National Academies of Science, weighed in on Keys's impoverished data, and on related claims that multiplied over the succeeding years, the media attacked the skeptics, heedless of statistical reasoning. Meanwhile, the food industry—apart from the protesting cattle and dairy lobbies—happily ministered to the new dietary wisdom. Government agencies weighed in with dietary guidelines that emphasized carbs and vegetables and warned that red meat was something one could only risk eating a few times a month. And when this miserable diet, shorn of taste, wearied its adherents, as it so often did, the pharmaceutical industry stepped in, offering drugs to lower cholesterol.
As the 20th century closed, the Owl of Minerva finally stirred in the light of unavoidable evidence: None of this advice was preventing heart disease. What was left, as Ms. Teicholz adumbrates, was a monstrous thought: What if the crusade against cholesterol had fed the spread of obesity by encouraging a population to retreat from the very foods that would have satiated its hunger more efficiently than the hallowed grains and fruits and vegetables of the great dietary pyramid? What if the low-fat mantra had driven a population into feeling perpetually hungry? What if you were better off eating meat, eggs and dairy than a diet bloated in carbs and vegetable oils?
It is a commonplace in public-health discussions of obesity to warn that the search for "perfect" or "better" evidence is the enemy of good policy and that we can't afford to wait for all the information we might desire when there is a need to do something now. Yet Ms. Teicholz's book is a lacerating indictment of Big Public Health for repeatedly putting action and policy ahead of good evidence. It would all be comical if the result was not possibly the worst dietary advice in history. And once the advice had been reified by government recommendations and research grants, it became almost impossible to change course. As Ms. Teicholz herself notes, she is not the first to point out that saturated fats have been sinned against by bogus science; and yet, the supermarket aisles are still full of low- and no-fat foods offering empty moral victories.
"The Big Fat Surprise" is more than a book about food and health or even hubris; it is a tragedy for our information age. From the very beginning, we had the statistical means to understand why things did not add up; we had a boatload of Cassandras, a chorus of warnings; but they were ignored, castigated, suppressed. We had our big fat villain, and we still do.