Sugar Fix

When sending their children off to school, parents should remember that the foods they pack in their child's lunchbox can affect attention and learning during the day.

The biggest change parents should make, say nutritionists, is to limit the amount of sugar that kids eat at lunch (and breakfast). Doing so can give them the cognitive stamina to concentrate on their classes through the afternoon, say University of Michigan researchers.

Although the brain needs carbohydrates like sugar to function, the best carbohydrates to give kids are complex carbohydrates, like those found in whole grain breads and cereals. Simple sugars, like those found in sweetened juices, sodas and fruit cups cause a spike in blood sugar.

That spike is followed by a corresponding crash caused by a flood of insulin, a hormone that clears sugar out of the blood and into the body's cells to be used for fuel. The insulin spike is responsible for the sluggishness one feels—whether you're a grown-up or a kid—after the body has swept excess sugar from the bloodstream.

The cycle of sugar highs and lows can leave your child slumping in his chair only an hour after lunch, right in the middle of English class. A well-balanced lunch will mean a steady attention span.

Kids who are nutritionally fit have more energy, stamina and self-esteem that enhance their ability to learn, says Susan Aaronson, a registered dietitian with the health promotion division of the University of Michigan in Ann Arbor.

Obesity is a huge problem for kids, she says, which some schools have been trying to help change through healthier lunchroom fare. But the best option is still packing a lunch for your child, because few schools monitor the foods that children choose to eat in the cafeteria line.

Since kids are liable to trade their food with friends and classmates, the best way to make sure you're sending them to school with food they will eat is to involve them in choosing their lunch in the first place. You may want them to eat a hummus sandwich on rye bread, but if they hate it, you can be sure it will end up in the trash.

The basic rule of thumb when packing a lunch is to include as much variety as possible. Small portions are less daunting. Kids are more likely to dig into a sliced apple or peel a Clementine than take on a huge piece of fruit. Veggies can be made palatable with a dip, suggests Aaronson.

Making sure that lunch includes a serving of protein and little bit of fat can also help your child stay engaged through the afternoon. Fat and protein are important because they slow down the digestive process, so the body won't get slammed with a surge of sugar.

Parents most often go wrong when it comes to choosing lunchtime drinks. Aaronson suggests only three choices: water, milk or 100 percent juice. Many kid-friendly juices are fortified with vitamins, but contain only 10 or 20 percent juice; the beverages are often packed with excess sugars in the form of corn syrup.

Aaronson's final words of advice for parents: keep it interesting. Continue to urge your child to try new foods now and then, especially as the school year progresses and you find yourself in a lunchtime rut. Your daughter may hate seven-grain bread, but whole-wheat pita may get a pass. Something different and a little hip, like a wrap, might be a big hit.