A recent study has determined a link between children having low performance in schools and their habits of eating fast food. The research came from Ohio University and looked into the eating habits of 11, 700 children to see if there were any links what they ate and their academic performances.

The findings were published in the journal Clinical Pediatrics and determined that even small increases in the amounts of fast food that children eat can have a detrimental affect on their academic performances. To set up the study, the researchers first looked at children aged 10 to see what they were eating and how they measured up in subjects such as science, math, and reading, after a three year period.

From the sample of children studied, half of them ate fast food anywhere from one to three times a week. Their results found clear associations in the not just eating fast food but in the frequency of how much fast food was eaten and worse grade scores throughout the three year period. Kid’s who ate fast food nearly daily had 20 percent lower test scores on average than kids who did not.

Despite the findings that link together fast food eating and less successful academic performance, the link is not explicitly clear and therefore can’t be stated be stated as causal quite yet. The researchers did account for some other factors however, like habits and backgrounds of the kids. These included their fitness levels, socioeconomic backgrounds, other eating habits, what types of neighborhoods they lived in with their families, and what type of school they attended. The findings still held true even while taking the other factors into account.

Researchers from the study who suggest that it is a causal relationship however, feel that the link between fast food and worsening test scores could be blamed on the low levels of iron in fast food that is a crucial ingredient for cognitive development. Others suggest it might be due to the impaired memory and lessoning of learning of skills that occurs when people eat diets high in sugar, cholesterol, and fat. Malnutrition and high levels of fat have been documented in rats to specifically induce cognitive impairment.

Many fast food restaurants have made attempts to combat their bad reputations as being unhealthy by making big menu changes. McDonalds has already made big changes in the past but is planning some new ones in the coming year. For one thing, the fast food giant is dropping five of their extra value meals. They will be removing eight menu items, and introducing a “Create Your Taste” option where customers will be able to request their sandwich ingredients specifically.

Although McDonalds is making moves to drop a lot of oversized meal options, their plan might be less health related and more skewed towards staying relevant with their competition like the popular Chipotle restaurants. The McDonald company’s stock dropped by six percent this year.

Despite the many concerns about fast food beyond cognitive development, in the United States 13 percent of all calories eaten by kids and teens is still accounted for by fast food.