A longitudinal study published this month in Clinical Pediatrics revealed that the more frequently fifth graders ate fast food, the slower their academic advancement over the course of three years.
Specifically, the standardized math test scores of students who self-reported eating fast food daily in the fifth grade improved 3.47 points less on average from the fifth to the eight grade compared to students who did not eat fast food. While students who only ate fast food four to six times per week did slightly better that those who ate fast food daily, their scores still improved less than children who only ate fast food one to three times per week. These children in turn progressed more slowly than children who did not eat fast food.
This pattern held mostly true for children’s test scores in reading and science as well, according to the study, conducted by researchers at Ohio State University and the University of Texas at Austin.
While the observational study does not demonstrate causation, the researchers identified and controlled for many potentially confounding factors associated with eating fast food that also could have influenced children’s test scores, such as socio-economics or competing priorities to studying. It also included a large group of 8,544 students nationwide.
“One possible mechanism for a link between fast food and academic growth is the consumption of fewer specific nutrients” that are critical to cognitive development, the researchers hypothesize. They explain, “Fast food meals are often deficient in a range of nutrients, [and] children who eat fast food several times per week may be at risk of not receiving enough of these nutrients to develop optimally.”
For example, “less than a third of fast food meals provide the recommended amount of iron,” which is “particularly” important to cognitive development, according to the researchers.
They also note that substantial research suggests high-fat and high-sugar diets in adults are associated with slower processing speeds and difficulty focusing. These are similar qualities to many fast food meals.
Other recent studies have also linked nutrition to academic performance and one suggested that providing a free, nutritious breakfast to all students in the classroom could help level the academic playing field among students of different socio-economic backgrounds. (Read more about the research HERE.)
Recommendations to reduce fast food consumption
Based on their findings and the broader body of evidence linking improved nutrition to academic success, the researchers suggest reducing how often children eat fast food could improve their test scores. But to do this, they recognize that communities must address the many reasons children eat fast food.
One reason parents opt for fast food is because they are tight on time or might not know how to provide fast, healthy meals to their children. A key strategy for reducing how often children eat fast food is educating parents about strategies for feeding their children healthy foods more easily, the researchers said.
They also suggest increasing the price of fast food to discourage serving it to children. They note a 10% price hike has been associated with a 5.7% reduction in fast food consumption by fifth graders, according to a study published in 2012 in the International Journal of Obesity.
“Thus, pricing and taxing are potential mechanisms for reducing fast-food consumption,” they said.
Limiting access to fast food also could reduce consumption, they say. They note that fast food restaurants tend to congregate around schools. With three to four times as many such restaurants located within 1.5 km of schools in Chicago than elsewhere in the city.
Likewise, “fast food is present within many schools themselves, including 10% of elementary schools, 18% of middle schools, and 30% of high schools,” the researchers note.
Reducing advertising for fast food in schools and during children’s programming also could decrease demand and consumption, according to the study.
The American Academy of Pediatrics has recommended many of these measures out of concern for childhood obesity, the researchers note, adding that “these statements may serve to benefit children’s academic and cognitive development as well.”