Researchers say they've found the most conclusive proof to date that a good breakfast translates into better grades for kids. In a large-scale study out of Cardiff University, researchers in Wales asked 5,000 children aged 9 to 11 to record everything they ate over 24 hours, from breakfast on the first day to breakfast on the second, reports the Guardian. The results showed that kids who ate a quality breakfast had twice the chance of receiving above-average scores in standardized assessment tests six to 18 months later, compared to those who skipped. The word "quality" is key: Kids who ate candy or other junk food for breakfast—about 20% reported doing so—saw no boost in scores.
This "offers the strongest evidence yet of links between aspects of what pupils eat and how well they do at school," says the lead author in a release. While breakfast programs "can be seen as an unwelcome diversion," they "might also deliver educational improvements," the researcher adds. The head of one school tells the BBC that teachers can tell which students have skipped breakfast. "By around 10am they start flagging," she says. "It has an effect on behavior and concentration." In fact, teachers in the study estimated that kids who come to school hungry lose about two hours of learning a day, notes the International Business Times. (This breakfast advice might be bogus.)