Fast food restaurants are major contributors to the ever-growing heart disease and diabetes epidemic in the U.S.A. Close to a quarter of Americans go to fast food restaurants at least twice a week. Most of their foods are known to be high in fat, sugar, and salt - which all contribute to heart disease.

Despite efforts to improve the quality of food in the fast-food industry, there have only been modest nutritional improvements, revealed a new study published in the American Journal of Preventive Medicine.

Researchers from the US Centers for Disease Control and Prevention (CDC) reported that for 2007-2010 adults in the US get more than 11% of their daily calories from eating fast food.

In fact, many major restaurant chains across the U.S. seem to be trying to encourage obesity by serving meals that have calorie counts far exceeding the daily recommended amounts.

Study leader, Mary Hearst, PhD, MPH, Associate Professor of Public Health at St. Catherine University in St. Paul, Minnesota, said:

"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."

She added:

"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."

MacDonalds sign in Times Square
One quarter of Americans eat at fast food restaurants twice a week

Hearst and colleagues gathered information from the University of Minnesota Nutrition Coordinating Center Food and Nutrient Database which contains menus from 22 different fast-food outlets.

The study team analyzed trends of the most eight common fast food restaurants in the U.S. over the past decades:
  • McDonald's
  • Burger King
  • Wendy's
  • Arby's
  • Taco Bell
  • Kentucky Fried Chicken (KFC)
  • Diary Queen
  • Jack in the Box
They selected the restaurants because they were all included in the database since 1997 and offered a defined set of menu items as opposed to "creating your own meal" style restaurants.

The Healthy Eating Index (HEI)-2005 was used to determine the nutritional quality of the meals.

The HEI-2005 score did increase over the 14 year study period. However, it was only a measly 3-points increase, from 45 in 1997/1998 to 48 in 2009/2010.

Of all the fast food chains, KFC was the only one that showed a somewhat significant improvement in nutritional quality - a nine-point increase.

Although the scores did not improve for fruit or vegetables, they did for meats, saturated fat and added sugars. Interestingly, the scores declined for sodium and milk/diary products.

Six of the fast food chains improved the nutritional quality of their food in accordance with the latest public health recommendations, crucial to tackling the country's high rate of diet-related chronic diseases.

With an average nutritional score of 48, the fast food restaurants fell 7 points below that of the average American diet (55), which is still considered to be far from healthy.

Dr. Hearst, said:

"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.

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."

Margo G. Wootan, DSc, of the Center for Science in the Public Interest, Washington, DC, said in an accompanying article that "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."

Written by Joseph Nordqvist