An Experiment to Evaluate Nutritional Content of Restaurant Meals After Calorie Labeling

Researchers Harvard Medical School, Johns Hopkins Bloomberg School of Public Health, and Brigham and Women’s hospital collaborated on a study between 2010-2014 that evaluated the nutritional content of restaurant meal purchases after calorie labeling was introduced. Although the menu labeling provision of the affordable care act was passed in 2018, McDonald’s voluntarily started menu labeling in 2012. Previous studies found that there was no association between labeling and the nutritional content of food purchased. Researchers of this study sought to asked the following question: does labeling fast food menus with calorie information affect nutritional quality of consumers' meal purchases?

The research design was to compare McDonald’s, that adopted menu labeling in 2012, to five control restaurant chains (Burger King, Subway, KFC, Wendy’s, Dunkin’ Donuts) that did not have menu labeling. Researchers had participants return the receipt and fill out a questionnaire that gathered information on demographics, food preferences, added condiments and beverage choice. To limit bias, researchers told participants that they were conducting a study on food and drink choices at fast food restaurants. The study consisted of about 2883 adults (age > 18), 2131 adolescents (age 11-20), and 433 children (age 3-15). To properly assess information collected for children, researchers gathered information from the parent or guardian of the children.

Data was compiled for nutritional content of food such as calories consumed, saturated fat (g), sugar (g), dietary fiber (g), and sodium (mg) pre- and post-labeling. Results showed the most statistically significant difference in data in the nutrient content and nutrient density consumed by adults. When comparing McDonald’s to other chains, adults consumed a lower amount of sugar and a lower amount of percent calories of sugar following menu labeling. However, when comparing McDonald’s to other chains, adults consumed higher amounts of percent calories from saturated fat and lower amounts of dietary fiber. Results also supported that children’s dietary fiber intake (g) were reduced post menu labeling.

Notably, that fiber content decrease in saturated fat content increase in the meals purchased by adults post many labeling. This specific change is associated with the increased risk of chronic diseases. Although adults only consume 10% of their total kilocalories from fast food, this negative change overshadows the positive change of the reduction in sugar content from meals purchases.

This natural experiment fits well in today’s context of literature because it supports other research about obesity prevention in children and adolescents. In the past five years, there has been an attack on sugar sweetened beverages and a promotion of healthy school lunch. By assessing nutritional quality of consumer meals purchased, the results may influence restaurants to lower their saturated fat intake and increase their fiber intake to also promote obesity prevention.

Something that was not discussed in the study because it was not statistically significant was sodium. Meals pre-and post labeling for both children and adolescents were around 1000 mg of sodium. It may be best to educate parents on the DRI for sodium, since the meals purchased by children and adolescents accounted for half of the total DRI for sodium. A future study should be conducted focusing on menu-label reading intervention. Participants should be monitored for the fast food choices they make following this intervention.

Reference:

Petimar, J., Moran, A. J., Ramirez, M., & Block, J. P. (2020). A Natural Experiment to Evaluate the Nutritional Content of Restaurant Meal Purchases After Calorie Labeling. Journal of the Academy of Nutrition and Dietetics, 120(12), 2039-2046. doi:10.1016/j.jand.2020.06.006