Many still consider breakfast to be the most important meal of the day. But getting your kids to eat something before school isn't always easy, especially for the health-conscious parent.  Jennifer Willoughby, a pediatric registered dietitian at Cleveland Clinic Children's, says building a better back-to-school breakfast starts with two key components.

"It's really important to give them something with a protein and something with a carbohydrate. Preferably a whole grain or a piece of fruit, something that will fill them up and keep them full when they go in for that first class of the day," said Willoughby.

She says some Greek yogurt and a handful of high-fiber cereal is a great breakfast before school. Willoughby says adding a piece of fruit makes it that much better because of the fiber content, which will make your kids feel fuller, longer.  A piece of whole wheat toast with some peanut butter is another option, as is oatmeal, with some peanut butter or mixed nuts as your protein source. A hard-boiled egg and a piece of fruit also works.

Willoughby says the key is that combination of a protein and a carbohydrate to fuel the body and the brain.  And the best part is a healthy breakfast can be quick and easy, too.

"It doesn't take a lot of effort. Have things ready in the morning that they can just grab and go, even if they do something as simple as a glass of low-fat milk and a baggie of cereal on their way to school. You still want to have that pairing there, but it can be easy, it can be fun," she said.

Willoughby says there is one thing you should always get your kids to have before school each day. It's a glass of milk because juices can be really high in sugar.