Adam Drewnowski is director of the Center for Public Health Nutrition at the University of Washington in Seattle and the co-author of a study published last week in the journal Health Affairs on the economic impact of following the 2010 US Dietary Guidelines.
People eat the foods they can afford
Drewnowski told FoodNavigator-USA: “Dietary guidelines need to take the economic dimensions of people's lives [into account]. Now, some nutritionists concerned with diets and health will tell you that this is not their job. Their job is to advise people on the healthiest possible diets that lower disease risk.”
He added: “[But] unrealistic advice is useless: people eat the foods they can afford. Dietary guidelines would benefit from a reality check.
“We looked in vain in the Dietary Guidelines 2010 for some acknowledgment that food costs do matter. There are factors other than nutritional literacy that might keep people from eating fish three times a week."
Foods high in saturated fat and sugar are cheaper
According to the study – conducted by Drewnowski and colleagues Pablo Monsivais and Anju Aggarwal – consuming the amounts of potassium and dietary fiber recommended in the 2010 Dietary Guidelines could prove “prohibitive” for people on low incomes unless food consumption patterns and relative food prices changed.
Rather than looking at optimum diets, the researchers looked at the actual diets of adults in King County, Washington to find out where people were typically getting potassium, fiber, calcium and vitamin D from.
While it was technically true that healthier diets need not cost more, some nutritionists spent too much time operating in a theoretical realm instead of looking at what people were actually eating, said Drewnowski.
“Of course, healthier diets need not cost more, if only the eating habits were different. But they aren’t. Given current food preferences and eating habits, more nutrient rich diets do cost more.”
Where are Americans getting their vitamins, minerals and fibers from?
While getting enough calcium was relatively easy, he added, “We found that increasing consumption of potassium… would add $380 per year to the average consumer’s food costs. Meanwhile, each time consumers obtained 1 percent more of their daily calories from saturated fat and added sugar, their food costs significantly declined.”
In general, vitamin D comes from milk and milk products, fiber from vegetables and grains, and potassium from fruit and fruit juices, he said.
“So vitamin D is not very strongly tied to diets cost because milk is relatively inexpensive. But fiber and potassium are associated with more costly diets.You can have lower-cost fiber from beans, and low-cost potassium from white potatoes, tomato juice, orange juice, and bananas. The contrast is bananas versus berries and potatoes versus peaches. All are good but some are cheaper than others.”
Guidance should help people identify affordable food choices
Dietary guidance should therefore help people identify the most affordable food sources of potassium, fiber, and vitamin D and to incorporate them into their diets, he said. It should also promote foods containing multiple nutrients.
“Our findings underscore the fact that dietary recommendations need to acknowledge that food costs are a driver of consumers’ food choices. Doing so would help make dietary recommendations more realistic for all Americans, particularly for lower income families."
Agricultural subsidies should be reoriented
The study findings also underlined the need for changes to the US food production and distribution system, claimed Drewnowski, who is a professor of epidemiology and director of the nutritional scences program at the University of Washington.
“The current system has proved to be remarkably effective in the provision of calories, but not as good at supplying nutrients. Reorienting agricultural subsidies and other incentives to support the production and distribution of vegetables and fruit would be an important step toward making these foods more available and affordable.”