UW News

March 8, 2007

Economic status plays big role in obesity

Put that cheeseburger down. Have a salad, for crying out loud! That’s the easy answer we like to give when confronted with the issue of obesity. After all, if you overeat or have an unhealthy diet, that’s your personal choice, right?

Not necessarily. Dr. Adam Drewnowski, director of the UW Exploratory Center for Obesity Research (ECOR), argues that foods that are rich in nutrients and lower in calories are also some of the most expensive foods, he argues, meaning that low- and middle-income families are left with little choice but to buy unhealthy food.

“Healthier diets are more expensive — there are inequities in our food system,” Drewnowski said in a presentation last Friday, as part of a conference on poverty and obesity. The event was sponsored by the UW’s ECOR and Center for Public Health Nutrition, as well as the RAND Corporation.

“The higher-cost, healthier foods are less available in working-class neighborhoods,” Drewnowski added. “They’re slipping out of the hands of low-income families.”

The issues of obesity and poverty have not always been considered related to each other, but more and more research in this area in the last several years has shown that obesity is certainly related to economic factors, not just individual choices. Drewnowski and his colleagues, like Washington State University (WSU) economist Trent Smith, are urging public health practitioners, economists, and the general public, to think of obesity this way.

“It costs more money to buy a grilled chicken breast than a hamburger,” Smith, an assistant professor at WSU, said during one of the conference sessions. “It takes more time and effort to prepare fresh, healthy foods than it does to have unhealthy fast food.”

Smith’s axiom makes a lot of sense on first glance one can buy a double cheeseburger for 99 cents, but a healthier chicken sandwich or salad might cost two or three times as much, if not more. But those differences don’t just appear on restaurant menus: they’re common throughout our food supply, at fast-food joints and grocery stores alike.

Drewnowski has led many research projects that examine the cost and nutrient level of food, as well as its energy density —- the number of calories in a particular amount of food. What he and his colleagues have found is disheartening: that energy-dense and nutrient-poor foods, like cookies or French fries, are much cheaper than higher-nutrient foods with lower energy density, like lean meats or fresh fruits and vegetables. Since the U.S. government has not maintained a national food cost database in the past, Drewnowski and others had to conduct extensive surveys to determine the true costs of all sorts of food.

“Up until now we were told that it all cost the same, and that it’s a person’s responsibility to buy and eat the healthiest foods,” he said. “I’m arguing that absolutely not, energy-dense foods cost less. There is a huge price gap between these foods.”

In fact, if you view food items by the amount of energy you get per dollar you spend, the price gap can be staggering. Because cheap foods are so much more energy dense and filled with empty calories than the healthiest foods, they may be hundreds or thousands of times cheaper for the amount of energy you get.

Food advertising is a testament to this widening gap, as well, by highlighting some of the cheapest, most energy-dense, sinfully delicious foods available: cheeseburgers, French fries, pizza, fried chicken, all available at very little cost. That world stands in stark contrast to the one presented in nutrition and health magazines, with a veritable cornucopia of fresh berries, asparagus, salad greens, bell peppers, broccoli, apples, and other produce — all, of course, far more expensive than the items on the fast food menu.

Those nutrient-rich foods are essentially luxury items for many working people, Drewnowski explained. And though there may be a few cheap foods that are relatively nutritious — cabbage, lentils, powdered milk, and so on —those are far less tasty and appetizing than empty-calorie foods with added fat and sugar.

“We tell people to buy healthy foods, and they run out and go get an order of French fries,” he said. “We say, ‘You have made the wrong choice.’ I would argue that they have made essentially the only choice available to them.”

Another important factor to consider in discussing obesity and diet is the amount of time people have available to make fresh, healthy foods, said Diego Rose, associate professor of nutrition at Tulane University and a fellow presenter at Friday’s conference.

The government’s estimates of poverty take into account only income, not the amount of free time available in the family, which can vary widely between a single-parent household and a family with one working parent and one staying at home. If you include time resources in the equations for household resources, Rose explained, then the poverty rate increases to include many more single-parent families with little time available for food preparation.

Rose suggests that public health programs should include far more resources for teaching food preparation, which is now getting short shrift in favor of instructing people on things like cost-effective shopping.

“We can help this problem with nutrition education, if we develop educational plans that teach how to prepare time-saving, nutritious meals,” said Rose.

Drewnowski and other nutrition researchers are also trying to find better ways to educate consumers on shopping for healthy food, and for designing food assistance plans and nutritious diets that better fit the individual needs and habits of lower-income families.