Breakfast is the first part of a day-long eating plan. Eating breakfast helps our bodies metabolize food more efficiently and cuts down on the urge to snack between meals. Unhealthy snacking for more than three days a week can increase your RealAge (physiologic age). Eating regularly helps break up long periods of fasting, meaning that our body doesn't have to gear up to digest a big meal after doing nothing for hours, which is not an efficient process. In addition, some researchers have hypothesized that we burn more fat during our waking hours, since we are more active. This means that we might burn off our breakfast calories more effectively than we would an overly large late-night dinner. However, this is still speculation.
A perhaps surprising health effect of eating breakfast is that it also makes your cardiovascular and immune systems younger. We don't know exactly why, but several theories exist. First, many cereals contain lots of soluble fiber, which prevents lipid buildup and thus helps prevent arterial aging. Fiber also helps decrease the risk of cancer. The average American eats 12 grams of fiber a day, but increasing your fiber intake to 25 grams a day can reduce arterial aging and make your RealAge as much as two years younger. Fiber is one of the "Fifteen Food Choices" that have definitely been shown to make a difference in how long and how well you live. Second, cereals are usually "fortified" with extra vitamins, minerals, and micronutrients. During breakfast, we get many of the essential nutrients that we may not get during the rest of the day. This is even more important if you don't eat lots of fruits and vegetables during the day, or if you don't take vitamin and mineral supplements regularly. Other typical breakfast foods (fortified fruit juices, yogurt, and whole fruit) contain essential nutrients such as vitamins C and D and calcium and magnesium.