Advising patients about how to prevent diet-related chronic diseases such as obesity, type II diabetes and cardiovascular disease presents significant challenges. Hardest of all may be communicating consistent and realistic messages, and ensuring that patients are willing and able to comply with this advice.
Because food choices influence and are influenced by economic, social and political institutions, it is difficult -- if not impossible -- to alter individual dietary behavior without also improving the economic, social and political environment within which individuals make food choices.
If dispensing dietary advice were sufficient to change behavior, diet-related chronic diseases would have vanished long ago. As early as the 1950s, cardiologists recommended dietary guidelines for prevention of coronary heart disease. Decades later, their advice still holds: Consume most daily energy from fruit, vegetables and grains (plant foods); less energy from meat and dairy foods (animal foods); and even less from processed foods high in fat, sugars and salt, and relatively depleted in essential nutrients (junk foods). Since then, dozens of domestic and international governmental and professional committees have reconfirmed the value of these recommendations for prevention of diet-related diseases in general, but to no avail. Such diseases remain leading causes of worldwide death and disability, in part because dietary advice is more easily dispensed than followed. Because of entrenched institutional barriers, particularly food industry pressures, neither clinicians nor patients get much help from official sources of this advice.
To illustrate how these pressures operate, consider the first two "key recommendations" of the 2005 edition of the Dietary Guidelines for Americans. The Guidelines, jointly issued by the U.S. Departments of Health and Human Services and of Agriculture (USDA) every five years since 1980, constitute an official statement of government policy regarding all federal nutrition education, training, food assistance and research programs. Although they are explicitly set forth as "science based," specific recommendations are invariably influenced by the economic interests of food industry stakeholders.
"Adequate nutrients": The first key recommendation is to "Consume a wide variety of nutrient-dense foods and beverages within and among the basic food groups while choosing foods that limit the intake of saturated and trans fats, cholesterol, added sugars, salt and alcohol." This statement translates as eat more fruit, vegetables and whole grains (nutrient-dense foods), eat fewer animal products (major sources of saturated fats and cholesterol) and eat less processed "junk" foods (major sources of trans fats, sugars and salt). The substitution of nutrients for actual foods in this recommendation obscures its basic point; it is best to eat more plant foods but fewer animal and processed foods.
If this message is obfuscated, it is surely because of its impact on sales of foods in the "eat less" categories. Policymakers learned this lesson in 1977. When Senator George McGovern's Select Committee on Nutrition and Human Needs released a report suggesting that Americans reduce consumption of meat, eggs, full-fat dairy products, sugars and salt, the affected industries protested and persuaded Congress to intervene. Their vigorous opposition established an apparently unshakable precedent that dietary advice must never suggest eating less of anything. Over the years, Dietary Guidelines committees have internalized this approach. The 1980 version of the sugar guideline simply said, "Avoid too much sugar." By 2005, under pressure from sugar industry groups, the Guidelines used 23 additional words to make the same point, beginning with "Choose and prepare foods and beverages with little added sugars or caloric sweeteners...."1
"Within calorie needs": In a similarly oblique fashion, the second key recommendation is to "Meet recommended intakes within energy needs by adopting a balanced eating pattern, such as the USDA Food Guide or the DASH [Dietary Approaches to Stop Hypertension] Eating Plan." This recommendation, aimed at obesity and its health consequences, translates to "eat less." But such advice directly conflicts with the USDA's primary mission, which is to promote greater agricultural production and sales.
As a result of USDA policies, the U.S. food supply provides a startling 4,000 kcal per day for every man, woman and child in the country (calculated as food energy produced, less exports, plus imports). Although this level is nearly twice the amount needed to meet average energy requirements, Congress continues to subsidize the production of commodity crops such as corn, soybeans and wheat. Cheap commodities promote the production of processed foods made with subsidized ingredients: corn sweeteners, soy oils and wheat starch. Subsidized corn and soybeans also are fed to farm animals and reduce the cost of meat. Low food costs encourage people to eat more.
The overabundance of calories forces companies to compete for sales by encouraging food consumption in more places, at more times of day and in larger amounts -- all demonstrably effective "eat more" strategies. Companies advertise relentlessly and even market directly to children. Taken together, "eat more" environmental cues encourage people to consume more energy than needed. The Guidelines may urge adoption of balanced eating patterns reduced in fats and sugars, but the food and restaurant industry spends billions of dollars to market processed foods and to lobby against "eat less" messages.
Health claims: As a result of Wall Street's insistence that companies increase sales in an overabundant food economy, food companies increasingly rely on health messages to sell food. In 1990, they pressed Congress to allow health claims on the new food labels authorized by the nutrition labeling act. Congress forced the FDA to begin approving claims backed by adequate science. The FDA approved some claims, but rejected others. Food companies objected to the rejections, took the FDA to court and, on the grounds of free speech, won the right to make claims that were supported by minimal research. The result is a cacophony of confusing and misleading statements on food products such as sugary breakfast cereals said not only to reduce the risk of heart disease or cancer, but also to boost immune function. These claims take advantage of new research findings, no matter how preliminary. Health claims can best be understood as about marketing, not health.
Environmental impact: If one problem with dietary advice is confusing messages, another is the potential consequence of dietary choices for agricultural production and its effects on the environment. Eating less saturated fat, for example, often means switching from beef to fish, chicken or lean pork. But overfishing has led more than 75% of the world's fisheries to hover on the point of collapse, meaning not only that entire species are approaching extinction, but also that food for much of the world's population may vanish unless people eat less fish. Fish farming (the practice of raising fish in tanks or enclosed ocean areas) is proposed as a sustainable solution to this problem but creates water pollution, spreads marine diseases and paradoxically requires catching large numbers of wild fish to use as feed.
As for chicken and pork, confined feeding operations overburden the ability of land and water to absorb the waste products. Although the volume of animal sewage in the United States far exceeds that of human sewage, animal waste is not required to be treated and represents a substantial health hazard. Nutrients, antibiotics, hormones and pesticides in the waste end up in nearby waterways, where they contaminate drinking water and eradicate marine life. More than half the antibiotics in the United States are used in animal agriculture, leading to a proliferation of bacteria resistant to common antimicrobial agents.
Recommendations: Individuals on their own make daily decisions about what to eat. But making healthful decisions in the current food environment puts individuals in conflict with larger forces in society. Similarly, clinicians who advise patients about dietary choices do so in conflict with the goals of food companies. Because an exclusive focus on individual behavior is demonstrably inadequate to change it, clinicians might do better by accounting for the context in which people make food choices. Only by addressing both will dietary advice stand a chance of being effective in promoting health and preventing disease.
People need to hear clear messages about what to eat. They also need a food environment that makes it easier for them to follow those messages. To achieve both, we need to change policy. Since 1980, U.S. food and nutrition policies have favored industry deregulation. With the advent of a new administration, this is a good time to reconsider this approach and to press for policies that are more supportive of healthful food choices. As starting points, we favor:
Development of dietary guidelines free of food industry influence.
Restrictions on marketing low nutrient-dense foods to children.
Restrictions on health claims that lack substantial scientific substantiation as determined by independent bodies.
Elimination of agricultural subsidies for commodity crops.
Today, so many Americans are demanding a food supply that is healthier for people and for the environment, that attempts to improve food policies can be considered a new social movement. On the production side, this movement focuses on community food security, organic production, local food, worker rights, animal welfare and fair trade, among other aspects. On the consumption side, the movement works to improve food marketing (especially to children) and school food, and to introduce food ranking systems and calorie labeling. Clinicians can help their patients and themselves to achieve healthier food choices by working to further these efforts.
Maya Joseph is a PhD candidate in political science at the New School for Social Research, where she studies American politics and teaches on the politics of food.
Marion Nestle is Paulette Goddard Professor in the Department of Nutrition, Food Studies, and Public Health at New York University. She also holds appointments as Professor of Sociology at NYU and Visiting Professor of Nutritional Sciences at Cornell. From 1986-88, she was senior nutrition policy advisor in the Department of Health and Human Services and managing editor of the 1988 Surgeon General’s Report on Nutrition and Health. She writes the Food Matters column for the San Francisco Chronicle, and blogs daily (almost) at http://www.foodpolitics.com/ and for the Atlantic Food Channel.
 Nestle M. Food Politics: How the Food Industry Influences Nutrition and Health. Berkeley: University of California Press; rev. ed., 2007.
 Nestle M. Ethical dilemmas in choosing a healthful diet: vote with your fork! Proc. Nutr. Soc. (UK) 2000;59:619-629.
 Monsivais P, Drewnowski A. The rising cost of low-energy-density foods. J Am Diet Assoc 2007;107:2071-2076.
 Wansink, B. Mindless Eating. New York: Bantam Books; 2006.
 100 Leading national advertisers. Advertising Age, June 25, 2007.
 Nestle M. What to Eat. New York: North Point Press; 2007.
 Pew Commission on Industrial Farm Animal Production. Putting Meat on the Table: Industrial Farm Animal Production in America. Baltimore, MD: The Pew Charitable Trusts and Johns Hopkins Bloomberg School of Public Health; 2008.
Image by kawanet, courtesy of Creative Commons license.