NEWS

Study shows education, not money, controls dietary quality in the U.S.

By DAVID WILLIAMSON
UNC News Services

Instead, barring extreme poverty, education appears to be the key factor, the UNC school of public health and medicine researchers found.  Better-educated people tend to eat healthier foods because they know that it’s good for them. 

One conclusion the social scientists drew is that even lower-income families can eat significantly more nutritious meals and improve their health outlook if they learn to make better choices when shopping for and preparing food. 

A report on the study, which is the first to document the importance of education over income in diet, appears in the July issue of the American Journal of Preventive Medicine. Authors are Drs. Barry Popkin, professor of nutrition, Claire Zizza, a postdoctoral fellow at the Cecil G. Sheps Center for Health Services Research, and Anna Maria Siega-Riz, associate professor of maternal and child health and of nutrition. 

“We undertook this research for two reasons,” Popkin said. "First, we wanted to learn what was the major component of socioeconomic status that led to dietary behavior change. Was it income, as many people assume, or education?” 

Second, the researchers wanted to know if dietary changes were increasing or decreasing disparities across racial and social and economic groupings, he said. 

“We found that education is the key factor explaining dietary change of U.S. adults over the past three decades,” Popkin said. “Moreover, we found that the disparity in dietary patterns has emerged in a major way so that less educated and lower-income adults today consume much less healthy foods overall than do higher income and better educated people.”

In the 1960s, few differences existed across education and income ranges in dietary quality, the team found. “To me, this is a major issue,” the scientist said.

The research involved analyzing nationally representative data from the 1965 Nationwide Food Consumption Survey and the 1994-96 Continuing Survey of Food Intake by Individuals, which included, respectively, 6,476 and 9,241 adults ages 18 and older. >Factored into the analyses was the Revised Diet Quality Index, a research instrument allowing investigators to assess the overall healthfulness of respondents’ diets and compare changes over time.

The U.S. Department of Agriculture supported the surveys, which involved interviewing Americans about what and where they and their children had eaten recently.

The highest quality U.S. diets were found among white women who had attended college. 

“From a public health standpoint these results, which indicate Americans are consuming better diets, may seem paradoxical because of the increasing prevalence of obesity in the United States,” he said.

“However, the diet quality index was constructed to reflect proportionately variety and moderation and not absolute quantities of food consumed. For example, the percent of calories from fat does not reflect the trend in total energy intake, which has been increasing.” 

Other areas of concern are the very small improvements in fruit consumption and the small shifts in the moderation component, which includes consumption of added sugar, salt, alcohol and discretionary fat, Popkin said. The National Institute of Child Health and Human Development supported the research through a grant to UNC’s Carolina Population Center.

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