New 14-year study in the American Journal of Preventive Medicine reports
San Diego, CA, May 7, 2013 – More than 25 percent of American adults chow down on fast food two or more times each week. Known for menu items containing high amounts of fat, sugar, and salt, fast-food restaurants have contributed to America's poor diets and increased risk of diet-related chronic diseases, like heart disease and diabetes. A new study funded by the Robert Wood Johnson Foundation's Healthy Eating Research program and published in the American Journal of Preventive Medicine presents results from a 14-year study indicating that fast food restaurant menus have only modestly increased nutritious offerings, and much improvement is still needed.
"Despite qualitative evidence that the fast-food industry is making improvements to the nutritional quality of at least some of their menu items, a quantitative evaluation of trends in the nutritional quality of fast food available in the marketplace was lacking," says lead investigator Mary Hearst, PhD, MPH, Associate Professor of Public Health at St. Catherine University in St. Paul, Minnesota. "This is the first study to quantitatively evaluate whether fast-food restaurant chains have improved the nutritional quality of their U.S. menu offerings over a period of time during which they have been encouraged to do so by governmental and nongovernmental agencies."
Hearst and the study team set out to examine trends at eight fast-food restaurants using data from 1997/1998 to 2009/2010 culled from the University of Minnesota Nutrition Coordinating Center Food and Nutrient Database, which houses menus from 22 fast-food restaurants. The investigators selected eight restaurants:
- Burger King
- Taco Bell
- Kentucky Fried Chicken (KFC)
- Jack in the Box
- Dairy Queen
Three criteria determined restaurant selection: Inclusion in the database since 1997; offering a defined set of menu items (i.e., not offering a kind of "create your own meal"); and inclusion of all standard menu items in the database.
To evaluate nutritional quality, researchers relied on the Healthy Eating Index (HEI)-2005, a metric developed by the U.S. Department of Agriculture and used for quantifying nutritional quality. The team expected index scores would fall below the score for the American food supply – 60 points of 100 – due to high fat and sugar and low fruit and vegetable content. It also expected to find an increase in HEI-2005 scores among these restaurants over the 14-year period.
Across the eight restaurants, the HEI-2005 score increased over the 14-year period. However, the increase was modest, from 45 in 1997/1998 to 48 in 2009/2010. KFC showed the greatest improvement with a nine-point increase and Jack in the Box, the second greatest with a seven-point increase.
Over the study period, scores did not change for fruit, whole fruit, total vegetables, dark green and orange vegetables, legumes, total grains, whole grains, and oils. However, scores improved for meat, saturated fat, and calories from solid fats and added sugars. Scores worsened for milk/dairy and sodium.
Six of the eight restaurants improved nutritional quality consistent with public health recommendations, an important observation for reversing the rising rates of diet-related chronic disease in the U.S. KFC led the restaurants in increasing vegetables and total grains and decreasing saturated fats and solid fats and added sugars.
The overall nutritional quality score associated with these eight restaurants, 48, fell below that of the average American diet in general, 55, which the USDA considers far from optimal.
"Given the role of fast food in Americans' diets, restaurants are in a unique position to help improve the diet quality in the U.S. by improving the nutritional quality of menu offerings," concludes Dr. Hearst. "Modest improvements in average nutritional quality of menu offerings across eight-fast-food restaurant chains were observed, which is consistent with both legislative efforts (e.g., banning trans fat) and the industry's own statements about creating healthier menu options. However, considering that fast food is ubiquitous in the U.S. diet, there is much room for improvement."
In a commentary accompanying the article, Margo G. Wootan, DSc, of the Center for Science in the Public Interest, Washington, DC, emphasizes that the nutritional quality of fast food has improved little, only three points out of the 100-point HEI-2005 scale. She says, "This tiny increase is disappointing, and a bit surprising, given the many pronouncements by companies that they have added healthier menu options, switched to healthier cooking fats, are reducing sodium, and are touting other changes in company press releases and advertising." Wootan outlines a six-step program for restaurants to offer and promote healthier options, firmly establishing that they can and must do better than the small improvements Dr. Hearst and her colleagues measured over 14 years.