You have probably heard that eating a healthy breakfast is important. After all, breakfast is often said to be the most important meal of the day. It's difficult to prove that any one meal is more important than another, but research does show that eating breakfast can lead to important health benefits.

Breakfast provides energy to start the day. This is especially important if you will be active in the morning, either through an early trip to the gym or if you have a strenuous job. But even people who are less active may find that they feel more alert if they eat breakfast – and not just because of the coffee.

Eating breakfast can help reduce hunger and overeating later in the morning or at lunch. This is why breakfast is often emphasized in weight loss diets. In fact, 78 percent of participants in the National Weight Control Registry report that they eat breakfast every day as a way to lose weight and keep it off. These “successful losers” have lost an average over 60 pounds, so their advice is worth paying attention to.

What is a healthy breakfast? Unfortunately, there is no specific answer to that question. I think most experts would agree that a good breakfast should include a combination of carbohydrates, protein, and even some fat but be low in added sugar. These broad guidelines suggest that there are many ways to create a healthy breakfast, even if it doesn't include traditional breakfast foods.

A better approach may be to identify foods that would be poor choices for breakfast. Chances are, if your breakfast doesn't include items from this list, you are on the right track. However, any of the following are true about your breakfast, it could likely use some improvements:

1. It has frosting on it

I think everyone would agree that foods that are frosted are better classified as dessert than breakfast. That said, from doughnuts to Pop Tarts to breakfast bars, many unhealthy breakfast foods are covered with a layer of frosting.

2. One of the ingredients is marshmallows

Just like frosting, breakfast foods that contain marshmallows are probably better choices for dessert. Marshmallows are found in cereals, granola bars, an other packaged foods that are almost always high in added sugars beyond the marshmallows.

3. It is topped with whipped cream

A fruit smoothie can be a healthy breakfast. But a fruit smoothie topped with whipped cream is likely closer to a milkshake as far as sugar and calories are concerned. The same goes for coffee drinks. A mocha-caramel latte with whipped topping may contain coffee, but it also has far more sugar, fat and calories than you might expect.

4. It contains chocolate

Research shows that eating chocolate may have health benefits. But the research involves consuming small amounts of dark chocolate, not chocolate doughnuts or chocolate-flavored cereal. Again, save the chocolate for dessert.

5. You’re eating it in your car

More specifically, you got the food while you were in your car, which means it likely came from the drive-through window at a fast-food restaurant. Fast food is just as poor of a choice for breakfast as it is for lunch or dinner.

Of course, there are exceptions to these guidelines. There is nothing wrong with treating yourself to a chocolate-frosted doughnut once in a while. But if your daily breakfast includes items from this list, you could benefit from a breakfast makeover, and this list should help you avoid many unhealthy choices.

Brian Parr, Ph.D., is an associate professor in the Department of Exercise and Sports Science at USC Aiken where he teaches courses in exercise physiology, nutrition and health behavior.

He is a member of the American College of Sports Medicine and is an ACSM certified clinical exercise specialist; his research focuses on physical activity in weight management and the impact of the environment on activity and diet.