ALLISON AUBREY, reporting:
I'm Allison Aubrey. When it comes to the brain and nutrition, there's lots of evidence to suggest that eating breakfast really can help kids succeed in the classroom. The reason is pretty straightforward: after fasting all night, developing brains needs a fresh supply of glucose or blood sugar.
Professor TERRILL BRAVENDER (Duke University): Without glucose our brain doesn't operate very well and people have difficulty understanding new information, they have difficulty with visual, spatial understanding, and they don't remember things as well.
AUBREY: Terrill Bravender is professor of pediatrics at Duke University. He says dozens of studies going back to the 1950s have consistently shown that children who eat breakfast, any breakfast, do better than those who don't.
In one study of 4,000 elementary school students, researchers gave half of the kids a morning meal and directed the other half to skip it. All of the children then took a battery of attention tests. Harvard psychologist Michael Murphy, who directed the study, says to measure, for instance, short-term memory, they used a digit span test.
Mr. MICHAEL MURPHY (Psychologist): We read a series of digits out loud - five, six, two - and asked them to repeat them. And we would read them longer and longer spans of digits, and the total score you get is the number of digits you were able to repeat correctly.
AUBREY: They also tested things such as verbal fluency. They asked children to name all the animals they could think of in 60 seconds. Across the board, Murphy says the breakfast eaters performed better.
So with the preponderance of evidence suggesting that breakfast really is key, the next question becomes does it matter what kinds of foods kids eat. Duke's Terrill Bravender says one thing he'd never serve his children is Froot Loops.
Prof. BRAVENDER: I hate to disown Froot Loops, but any sugared cereal really has a high glycemic index. And I think that not only is breakfast important by itself, but the composition of the breakfast is really important too.
AUBREY: The glycemic index is basically a measure of how quickly the body absorbs a carbohydrate and converts it to fuel. When it comes to sustained brain power, Bravender explains that food low on the scale, such as less-refined whole grains, are preferable. He says even though a bowl of Froot Loops and a bowl of old fashioned oatmeal may have the same number of carbs, they have different glycemic loads.
Prof. BRAVENDER: The Froot Loops will get in your body really quickly and cause a peak in blood sugar levels that then falls pretty dramatically after about two hours or so. The oatmeal, on the other hand, is absorbed a lot slower. And so you get a nice, slow rise in blood sugar levels, a nice amount of energy to last through the morning and you don't get that fall.
AUBREY: Bravender says this fall or dip in blood sugar can bring with it a release of hormones that can affect mood.
Prof. BRAVENDER: Those hormones are a signal to the body that something stressful is going on. And the response of many people to those hormones is to eat.
AUBREY: In some children, those hormones and the hunger can lead to distraction and lack of concentration. Recently scientists have begun to study this phenomenon. Last year, Tuft University psychologist Holly Taylor had one group of elementary school children eat oatmeal for breakfast. Another ate Captain Crunch. Then both the groups were given some tasks, such as memorizing the names of countries on a map. The oatmeal eaters did up to 20 percent better on the tests.
Ms. HOLLY TAYLOR (Psychologist): There were enough to show that the children were remembering more information about these maps after having eaten oatmeal.
AUBREY: Both cereals have the same amount of sugar, but Taylor says the difference is that the oatmeal had more protein, more fiber and therefore a lower glycemic index. These findings beg more research, but Duke's Terrill Bravender says they do suggest some basic rules.
First, families should focus on making sure that kids do eat something for breakfast. And if you are trying to track glycemic load, a quick shortcut is to serve less processed foods that have some protein and fiber. This will improve the odds that your child's blood sugar will hold steady until lunch.
Allison Aubrey, NPR News in Washington.
INSKEEP: And that's your health for this moment. Excuse me a moment while I go get some oatmeal. For our experts' picks on the best breakfast, go to NPR.org/yourhealth. Now, if you'll excuse me, I'm going to go get some oatmeal.