Fast Food, Slow Learning
Everyone knows that brain food isn’t usually handed out at drive-through windows, but could pizza and burgers be especially detrimental to growing minds? A study by Elizabeth Gershoff, associate professor of human development and family sciences, examined the culinary habits of fifth-graders and their subsequent academic performance as eighth-graders to find out.
The more often fifth-graders ate fast food, the worse the improvement rate in their reading, math and science test scores were by eighth grade. Students who didn’t eat fast food had 20 percent higher test score gains than those who ate the most fast food.
“The most detrimental findings were in kids who ate fast food every day,” said Gershoff. “Any effort parents can make to scale down from that is great.”
Many factors can influence test scores—bedtime, exercise, screen use and socioeconomic status, to name a few—so the authors carefully controlled for these. They even controlled for other differences in diet, such as the amount of vegetables, milk and soda children consumed.
“We tried to rule out all possible explanations, but the link was still there,” says Gershoff.
The study didn’t pinpoint the exact mechanisms behind reduced test scores, but other studies have shown that fast food lacks certain nutrients, especially iron, that aid cognitive development. Also, diets high in fat and sugar have been shown to hurt memory and learning.