November 13, 2008
Drewnowski to give Public Health’s Distinguished Faculty Lecture
Adam Drewnowski, UW professor of epidemiology and medicine, will give the School of Public Health and Community Medicine’s Fall 2008 Distinguished Faculty Lecture on Wednesday, Nov. 19. The lecture, Food, Incomes, and Health, will take at 4 p.m. in T-639, Health Sciences Center.
Drewnowski is director of the UW Center for Public Health Nutrition and the UW Center for Obesity Research, and a member of the Fred Hutchinson Cancer Research Center. He is a world-renowned leader in innovative research approaches for the prevention and treatment of obesity. Drewnowski obtained his master’s degree in biochemistry from Oxford University and his doctorate in psychology from The Rockefeller University in New York. The author of more than 100 research papers along with numerous reviews and book chapters, he is a frequently invited speaker at scientific meetings, conferences, and symposia.
By Adam Drewnowski
Professor of Epidemiology
We have been told — all too often — that rising obesity rates in the United States were the result of a toxic food environment. Not so. All evidence suggests that obesity is the toxic consequence of a failing economic environment. The social and economic policies of the past two decades have created an American underclass — which is obese and increasingly diabetic. The consequences of fiscal deregulation, spanning several previous administrations, will plague the health system for years to come.
We were told that obesity was genetically driven, much like height. Not so. Both obesity and diabetes follow a social gradient. Bodies do not lie. High body weight, an infallible index of lower social class among women, is associated with economic insecurity and social distress. The social gradient applies equally to geographic measures. Upscale neighborhoods are lean; poor neighborhoods are more likely to be obese. Across King County, obesity rates ranged from a low of 5 percent to a high of 30 percent depending on zip code location. Seattle real estate prices, a good index of area poverty or wealth, were a reliable predictor both of obesity and of diabetes related deaths.
We were told that obesity was the result of poor choices regarding fitness or diet. Not so. The carefully fostered illusion of freedom of choice disguises the fact that most people have none. Energy-dense foods, many of them nutrient-poor, are good tasting, readily available — and above all cheap. Often, they are the only real options for the low-income consumer. Yet households selecting fast foods in preference to fresh vegetables and fruit are typically accused of laziness, self-indulgence, and moral failure. The blame spreads from bad people to bad foods. Fast foods, beverages, snacks and desserts, added sugars and fats are further blamed for causing addiction, promoting appetite or blocking satiety. Few have thought to ask whether low-income households were simply making the only economic choices available.
The skyrocketing food prices have put the global obesity issue in a new and starker perspective. Speaking at the 2008 High-level Conference on World Food Security in Rome, Margaret Chan, the director general of the World Health Organization, said: “Food choices are highly sensitive to price. The first items to drop out of the diet are usually healthy foods — fruit, vegetables, and high-quality sources of protein. Nutrient-poor staples are often the cheapest way to fill hungry stomachs.” She reiterated those words at the 2008 Pacific Health Summit in Seattle.
That declaration was directly based on our research on diet quality and diet cost. Simply put, fats and sweets cost less, whereas healthier diets cost more. As incomes drop and food budgets shrink, food choices shift toward energy-dense refined grains, added sugars and fats. Whereas higher food spending does not guarantee a better diet, reducing spending below a certain minimum virtually ensures that the resulting diet will be energy-rich but nutrient-poor. Computer optimization programs, driven by cost constraints only, consistently create diets similar to those that are already consumed by the poor. Better diets not only cost more but are more likely to be consumed by the more affluent groups.
The obesity debate in the U.S. has steered clear of the too complex issues of social class. Rather, much time was spent on genetics, physiology, race/ethnicity, personal responsibility and freedom of choice. Some in public health nutrition have adopted the view that most Americans could follow a healthy diet but simply choose not to. Attempts to improve population dietary habits have stressed individual food choice behavior, psychosocial factors, self-efficacy, and readiness to change. Official guidelines such as the 2005 Dietary Guidelines for Americans and USDA MyPyramid, exhorted consumers to “choose” healthful diets as opposed to unhealthy ones, somewhat like choosing chocolate over vanilla ice cream.
The issue of cost was never mentioned. Yet replacing fats and sweets with more vegetables and fruits was associated with higher diet costs. In epidemiologic studies, each 100 g increment in additional fruit and vegetable consumption increased diet costs. In contrast, higher consumption of fats and sweets was associated with a net savings in diet costs. Whereas sweets and fats cost less, low-energy-density diets high in vegetables and fruits cost more. People who had lower-cost diets, generally consumed more calories: it was possible to pay less and eat more. The key predictor of weight gain may not turn out to be sugar or fat — but simply low diet cost.
The issue of access to food sources is only now getting recognition. Minorities and the poor are at a disadvantage when it comes to the adoption of healthier eating habits. Poor neighborhoods attract more fast food outlets and convenience stores as opposed to full-service supermarkets, an issue sometimes framed in terms of social justice. However, given that many healthful foods have become luxury goods, their availability is driven by neighborhood buying power. Furthermore, there is a risk of trivializing the term. Social justice has less to do with larger portions of broccoli and more to do with eroding minimum wage, lack of health care, and wholesale looting of the American economy. It is a shame that many of the current strategies for obesity management are based not around alleviating poverty but around recommending high-cost foods to low-income people. That approach will not work in the U.S. or elsewhere.
The dual burden of disease, undernutrition and overweight now faced by developing nations is another economic issue that is directly linked to poverty, food prices and diet costs. The relation between food, incomes and health should once again become a priority for global public health. The major policy and political challenge for global nutrition is to ensure a supply of affordable healthy foods to all.
This article is scheduled to be published in the Spring 2009 issue of Spotlight on Research, UW School of Public Health and Community Medicine.