How the Ideology of Low Fat Conquered America


This article examines how faith in science led physicians and patients to embrace the low-fat diet for heart disease prevention and weight loss. Scientific studies dating from the late 1940s showed a correlation between high-fat diets and high-cholesterol levels, suggesting that a low-fat diet might prevent heart disease in high-risk patients. By the 1960s, the low-fat diet began to be touted not just for high-risk heart patients, but as good for the whole nation. After 1980, the low-fat approach became an overarching ideology, promoted by physicians, the federal government, the food industry, and the popular health media. Many Americans subscribed to the ideology of low fat, even though there was no clear evidence that it prevented heart disease or promoted weight loss. Ironically, in the same decades that the low-fat approach assumed ideological status, Americans in the aggregate were getting fatter, leading to what many called an obesity epidemic. Nevertheless, the low-fat ideology had such a hold on Americans that skeptics were dismissed. Only recently has evidence of a paradigm shift begun to surface, first with the challenge of the low-carbohydrate diet and then, with a more moderate approach, reflecting recent scientific knowledge about fats.

For years I suspected there was no good medical reason for all Americans to follow the prescribed low-fat diet, and I wondered where these low-fat recommendations came from. Nineteenth-century French health manuals, for example, recommended individualized diets based on geography, age, sex, occupation, and constitution. This orientation may have been what historian William Coleman called “a medical doctrine for the bourgeoisie”—but this approach always made more sense to me than what I came to see as the reigning ideology of low fat—a one-size-fits-all dietary approach.1 Why were all Americans supposed to drink nonfat milk and avoid cheese? Had scientific medicine constrained our choices? Positivism with its universalizing model? Our Puritan heritage? Were we dealing with a recent medical fad? In this article, I aim to answer the question that has perplexed me for so long: how did the ideology of low fat conquer America?

I use the term ideology because I came to see low fat as an overarching belief that captured the minds and hearts of American medical and diet culture in the 1980s and 1990s. Supported by scientific studies, promoted by the federal government, the food industry, and the popular media, low fat became the dominant dietary belief of health care practitioners, health popularizers, and a substantial part of the American populace.

The historical centralization of the ideology of low fat in the late twentieth century appears to have had four major strands: (1) the American tradition of low-calorie, low-fat diets for weight reduction, (2) the diet-heart hypothesis dating from the post-World War II era, (3) the politics of food and low fat, and (4) the promotion of low fat by the popular health media.


Slimming or reducing was a widespread social and cultural phenomenon among some groups of American women from the late nineteenth century, waxing and waning in response to changing cultural, social, political, and economic conditions. Historian Peter Stearns has shown that by the early twentieth century, America had a firmly entrenched dieting culture. This was especially true of middle- and upper-middle-class white women. The impetus for the low-calorie, low-fat diet was medical for some but aesthetic for most. Women dieted in search of slimmer bodies, better to look good in the more revealing, fashionable clothes of the 1920s. They embarked on slimming regimes with and without the advice of physicians. Women’s magazines regularly featured diet columns, diets, and recipes. Counting calories was the preferred approach. Because educated dieters knew that fat grams had nine calories each, whereas protein and carbohydrate grams had only four, low calorie was for all practical purposes low fat.2

Although bodies had been quantified since the early nineteenth century,3 Americans, especially women, began to weigh themselves regularly from the late nineteenth century on. Public or penny scales became available in the 1890s, and private (bathroom) scales were available from 1913. Insurance companies also participated in the quantitative approach with their ideal and desirable weight charts, introduced in 1942, reissued with lower weights in 1959, then periodically thereafter—until replaced in the 1990s by the Body-Mass Index (BMI) as the table of choice.4 As early as pre-World War I, the notion that one’s weight as a young adult, say, at age of eighteen or twenty-five should remain the lifelong weight was promulgated, even though this idea flew in the face of the observation that people tended to gain weight as they aged. As the cult of youth became a national imperative later in the century, the idea of a lifelong stable weight, supported by statistical and medical research, gained more credence. Bodies should not get heavier with age, and hence men and women of all ages should weigh the same as they had at eighteen or twenty-five. This notion of weight stability is, however, contested. Statisticians at the U.S. Centers for Disease Control and Prevention (CDC) have recently challenged this idea, providing data to show that being slightly overweight is health-promoting, especially in older people.5

The main point here is that the low-fat diet for weight reduction was already well in place before physicians and scientists began promoting it for cardiovascular health in the 1950s. The low-fat diet was part of our dieting tradition before the ideology of low fat conquered America. But until the 1980s, the low-fat approach did not rise to the level of an ideology—the faith-inspiring and widely accepted notion that a low-fat diet was good for all Americans. A century-long preference for slim bodies and the well-entrenched practice of reducing weight by using a low-calorie, low-fat diet explains how the ground was already prepared for the widespread acceptance of the diet-heart hypothesis introduced shortly after mid century.

Yet, even though Americans were familiar with the low-fat, low-calorie diet, and some Americans followed it for weight reduction purposes, at mid century the typical middle-class American did not eat a low-fat diet. Rather there was more emphasis on meat, less on fruits and vegetables. Even before the era of fast food dating from the 1950s, Americans were consuming high-fat all-American favorites, such as meat stews, creamed tuna, meat loaf, corned beef and cabbage, mashed potatoes with butter, breaded and fried veal cutlets, deep-fried vegetables, French fries, lamb chops, liver, cheesecake, butter, and whole milk. Americans preferred marbled beef from cattle that were grain—not grass—fed, not free-ranging but fattened up in feed lots to produce tender, succulent, high-fat meat.6

In the South at mid century, popular foods included greens and beans with ham hocks, fried chicken, country ham, biscuits and cornbread with butter or gravy, sausages, and sausage gravy. Desserts were a staple, including homemade pies of all sorts, ranging from fruit to chocolate, banana cream, coconut, and pecan. Lifestyle author Anne Barone recounts growing up in the 1950s in Bible-belt Texas, where, she reports, “The only sanctioned pleasurable activity was eating.” She reminisces about church family-night dinners as veritable “food orgies.”7

Barone grew up with values shared by many Americans that predisposed her to a certain kind of fat-promoting eating. Those values are reflected in the following popular dicta regarding consumerism: bigger is better; get your money’s worth; quantity over quality; a general impatience meant that eating was similar to going to the filling station—fill ‘er up and fast.8 Barone recalls that as a fat teenager in Texas, she ate few fresh fruits and vegetables. The quality of produce available in supermarkets was uniformly low, a situation that explained the preference for canned fruit and vegetables. By contrast, the quality of desserts was high: homemade cakes, pies, and cookies abounded.

Within the context of a regionally diverse American diet, popular attitudes toward food, and technological changes, medical researchers began by the late 1950s to recommend the low-fat diet. At first they directed their advice to those Americans with what were called by 1961 “factors of risk” (later risk factors) for coronary heart disease. But by the 1980s, the preaching of the low-fat diet began to be directed to all Americans as a general preventive measure.9


In the 1940s, coronary heart disease was the leading cause of death in the United States. Scientists and physicians sought to identify the causes of heart disease in an effort to promote preventive measures.10 A host of studies ranging from the decades-long (and still continuing) Framingham study to the Seven Countries study of Ancel Keys et al. to localized studies, both in the United States and abroad, suggested a strong correlation between diets high in saturated fats and cholesterol and increased incidence of cardiovascular disease.11 There were scientific and medical skeptics, of course, and some studies failed to support what became known as the diet-heart hypothesis. In short, the diet-heart hypothesis held that diets high in saturated fats and cholesterol were a major cause of coronary heart disease.12

In the 1950s, Keys and others promoted a low-fat diet—a special variety of which Keys labeled the Mediterranean diet—with less meat, more grains, vegetables, fruits, and some olive oil.13 In 1957 the American Heart Association (AHA) proposed that modification of dietary fat intake would reduce the incidence of coronary heart disease.14 In 1961, William Kannel et al. published their landmark paper “Factors of Risk in the Development of Coronary Heart Disease,” and in the ensuing years the term “risk factor” became commonplace.15 That same year the AHA published a report on prevention of coronary heart disease that singled out reducing certain kinds of dietary fat intake as a way to lower the level of risk. The report was cautious, however, stating: “It must be emphasized that there is as yet no final proof that heart attacks or strokes will be prevented by such measures.” These recommendations were for those who by heredity or prior heart attack or stroke were prone to cardiovascular disease. The AHA did not recommend a low-fat diet for all. Subscribing to low fat in the 1950s and 1960s was in fact a modest proposal. The report recommended that Americans eat less fat and substitute “a substantial part” of liquid vegetable oils for solid animal fats, such as butter and fatty meat. This report was important because it also singled out overweight Americans as a group that should lower the fat content of the diet as a way of reducing calories.16

Daniel Levy, current director of the Framingham Heart Study, maintains that in spite of the AHA’s 1961 recommendations, there was no sense of national urgency concerning the relationship of dietary fat to heart disease until 1977. That year, the U.S. Senate’s Select Committee on Nutrition and Human Needs, chaired by George McGovern, put the diet-heart hypothesis on the national agenda with its publication of the “Dietary Goals in the United States.” Indeed, Levy claims that this report was “the first comprehensive statement by any branch of government on risk factors in the American diet.”17 As McGovern stated: “Too much fat, too much sugar or salt, can be and are directly linked to heart disease, cancer, obesity and stroke… .”18 The publication of this report led to the publication every five years of the U.S. Dietary Guidelines. For the first time, the federal government told Americans to eat more fruits, vegetables, whole grains, poultry, and fish, to eat fewer high-fat foods, and to substitute nonfat for whole milk. But in these same years, social, economic, and technological forces were at work to sabotage these optimistic—and perhaps misguided—efforts to change Americans’ eating habits.19

Even though many diet-heart studies focused on high-risk patients, and although the proposed massive Diet-Heart study of the late 1960s and the early 1970s was abandoned for lack of money and methodological problems, a host of scientific studies supported the low-fat approach.20 A turning point in obesity/heart disease studies came in 1983 with the publication of an article based on the Framingham studies, which cited obesity as an independent risk factor for heart disease.21 This finding lent further support to the low-fat approach because scientists believed that the low-fat diet might not only prevent coronary heart disease, but also could promote weight loss, thereby reducing the incidence of obesity. By 1984, the scientific consensus was that the low-fat diet was appropriate not only for high-risk patients, but also as a preventive measure for everyone except babies.22 Low fat carried the day, in spite of continued serious skepticism.23 The diet-heart hypothesis remained a hypothesis, but, as if already proven, it became enshrined in federal public health policy and was promoted by health-care practitioners and the popular health media. By 1988, the Surgeon General’s report emphasized the health dangers of dietary fat, and in 2000, the federal government’s “Report on Nutrition and Health” labeled fat the unhealthiest part of the American diet. From 1984 through the 1990s, dietary fat was increasingly blamed not only for coronary heart disease but also for overweight and obesity.24

In 1984, the National Institutes of Health (NIH) Consensus Development Conference issued its Consensus Statement, entitled “Lowering Blood Cholesterol to Prevent Heart Disease,” which was endorsed by the American Medical Association (AMA) and the National Heart, Lung, and Blood Institute (NHBLI). Although some scientists and physicians remained unconvinced by the data, the argument in favor of the low-fat diet for all carried the day, following the recommendations of the Consensus Report. Here was a chance for the food industry to profit from scientific research and for Americans to participate in the reigning health crusade.25


According to academic nutritionist Marion Nestle, “The U.S. government has been telling people what to eat for more than a century… .”26 By 1977, as we have seen, the federal government was telling people to eat low fat. This history of federal involvement in the American diet is essential for understanding how low fat conquered America in the 1980s and 1990s. The United States Department of Agriculture (USDA), established in 1862, had two main duties: to ensure a sufficient and reliable food supply and to provide information on subjects related to agriculture, the latter charge being interpreted to mean making dietary advice available to citizens. In 1917, the agency laid out five basic food groups: fruits and vegetables, meats and other protein foods, cereals and other starchy foods, sweets, and fatty foods. By 1958, the food groups were reduced to four: milk, meat, vegetable/fruit, and bread/cereal. In 1941, the Food and Nutrition Board of the U.S. Academy of Sciences introduced Recommended Daily Allowances, or RDAs, and from 1943 the department has produced revised versions at regular intervals.27

In 1968, the Senate appointed George McGovern to chair a Select Committee on Nutrition and Human Needs mandated to look into the problem of hunger in America. This committee, which met until 1977, was instrumental in the federal government’s promotion of low-fat diets. During the nine years of hearings, the committee’s focus shifted from its initial emphasis on hunger and the poor to chronic disease and diet. Committee members became convinced that Americans were not only eating too much, but were also eating the wrong foods.28

The committee’s work culminated in its early 1977 report, Dietary Goals for the United States, which promoted increased carbohydrate and reduced fat consumption along with less sugar and salt. The report recommended that Americans eat more fruits, vegetables, whole grains, poultry, and fish, less meat, eggs, and high-fat foods, and that they substitute nonfat for whole milk. Critics, both scientific and industrial, called the diet-heart hypothesis unproved and the dietary recommendations disputable. Under pressure from many constituencies, but especially the food industry, the committee revised and reissued its report later in the year. The revision modified the cholesterol recommendations and changed the wording from the negative, such as “reduce meat consumption,” to the more open, “choose meats and fish that will reduce saturated fat.”29

With the publication of the Dietary Goals, the federal government officially supported the low-fat approach. In 1978–79, the American Society of Clinical Nutritionists, the AHA, and the National Cancer Institute fell in line with their own low-fat recommendations. By 1980, a scientific consensus was emerging that a low-fat diet was needed to prevent the two leading causes of death, coronary heart disease and cancer. Federal government support for low fat continued with each official government publication from the 1979 Surgeon General’s Healthy People to the Dietary Guidelines for Americans, first issued in 1980 and every five years thereafter (a joint effort of the Department of Health and Human Services (HHS) and the USDA). Thus, by the 1980s, in spite of protests from the food industry and skeptical scientists, federal agencies forged a consensus on dietary advice at the same time that a growing scientific consensus advocated low fat for everyone. By the end of the decade, both the controversial Surgeon General’s Report on Nutrition and Health and the World Health Organization (WHO) were promoting low fat.30

Although the food industry had initially worried about the low-fat approach, by the 1980s food producers had begun to realize that low fat could provide profit-making opportunities. The industry began replacing fat with sugar in processed foods, leading to what would by the 1990s become known as the “Snackwell’s phenomenon,” low-fat foods that had just as many calories as the former high-fat versions.31 Driven by consumer demand and widespread advertising, in the 1980s and 1990s low-fat industrial foods proliferated to fill grocery store shelves. In 1992, after much controversy and negotiation, the USDA released its first and long-awaited food pyramid that lent full support to the ideology of low fat. Wide press coverage gave the pyramid much publicity, and it quickly became an icon. The pyramid soon became, according to Nestle, the “most widely distributed and best recognized nutrition education device ever produced in this country.”32 Meanwhile, the AHA launched its own low-fat campaign. In 1988, in an effort both to raise funds and promote better health, the AHA introduced its program to label foods with its “heart healthy” seal of approval, the now-familiar heart with the white check on it (Figure 1). Food companies would pay to label their foods with the AHA seal of approval. By 1990, endorsed food products started to appear in grocery stores, but there was a problem: fresh foods were not labeled. This exclusion could suggest to consumers that processed foods were the heart-healthiest. Following protests, the AHA withdrew the program, but reinstated it in 1993. By 1997, fifty-five companies were participating with over 600 products certified, many of which were cereal products, including Kellogg’s Frosted Flakes, Fruity Marshmallow Krispies, and Low-Fat Pop-Tarts.33

Fig. 1.

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