Skipping breakfast can cause irritability, fatigue

In the rush to get ready to go to work or class, skipping breakfast may be more harmful than one might think. 

According to a study conducted on more than 1,000 volunteers by the Journal of the American College Nutrition, people who ate a complete breakfast containing more than one-quarter of their daily calories consumed less fat and more carbohydrates throughout the day than those who skipped breakfast. 

Volunteers who ate breakfast also had a higher intake of vitamins and minerals and lower cholesterol levels. 

Another study conducted by the International Journal of Food Science and Nutrition found that people who ate cereal for breakfast every day felt better physically and mentally than people who did not eat breakfast. 

Maybe the old saying is right - breakfast is the most important meal of the day. But why exactly is this? 

During the typical eight-hour time period between dinner and breakfast, the body needs fuel for the many autonomous functions that take place while sleeping. This fuel is provided by glucose stored in the blood, muscles and the liver. 

More than half of the body's glucose is gone by morning, which means the body is basically fasting, so the name "breakfast" is fitting.  

The body needs a meal in the morning to regain this lost energy. While a burst of energy is naturally felt after sleeping, this energy will wear off as the day progresses. If one does not eat breakfast, the body will eventually be running on empty.  

Skipping breakfast can cause blood-sugar levels to drop, which can cause fatigue, irritability, lethargy and poor concentration. Compensating by eating a large lunch in the afternoon may boost energy levels somewhat, but will not make up for an entire day's worth of energy, according to dietician Elizabeth Somer in a WebMD interview. 

The food breakfast consists of is important as well. Breakfast should include at least one serving of fruit, which will increase the chances of consuming the recommended five servings of fruits and vegetables per day, according to Gloria Stables, director of the National Cancer Institute's "five-a-day" program. 

"People who skip breakfast generally fall short on the recommended servings, especially of fruit," said Stables. "If you don't get started with your first meal of the day, it's awfully hard for most people to catch up later." 

Drinking a tall glass of orange juice at breakfast provides more than a healthy dose of vitamin C. According to a study conducted by the American Journal of Clinical Nutrition, drinking a glass of orange juice every day increases HDL cholesterol, which helps keep arteries clear.  

Orange juice is also a good source of potassium, which can lower blood pressure and decrease the risk of a stroke. 

The body needs 25 to 30 grams of fiber per day. However, the average American only eats about 13 grams per day, according to the AJCN. The study found that women who ate breakfast cereals rich in fiber, and consumed 23 grams of fiber per day, were 23 percent less likely to have heart attacks than those who consumed 11 grams per day.  

The same study conducted with men found that a high-fiber diet reduced the chance of heart attacks by 36 percent. 

Most of these breakfast cereals also are fortified with vitamins and minerals, including folic acid. Folic acid prevents birth defects and can lower the risk of heart disease and colon cancer. 

Eating a high-fiber breakfast can also help people lose weight. According to a study conducted by The Journal of the American Medical Association, people who eat a high-fiber diet are less likely to gain weight than those who do not eat enough fiber.  

This may be because high-fiber foods slow the digestive process, which can ward off feelings of hunger later in the day. 

For those who perpetually skip breakfast, eating breakfast should "reset" their appetite clock in two to three weeks, according to Somer. After this time, one should feel a boost in energy and fewer problems with overeating throughout the day.