Why eating the right breakfast is so important

Roll your eyes if you like, but the old bromide about breakfast being the most important meal of the day is true (mostly). Breakfast eaters tend to have better diets overall, consuming more fruit, vegetables, milk, and whole grains than non-breakfast eaters.

And because the time between dinner and the next morning's meal is the longest your body goes without food, breakfast has an effect on you that's different from any other meal. Eating within 2 hours of waking can make a difference in the way you metabolize glucose, or blood sugar, all day. Your glucose level rises every time you eat, and your pancreas produces insulin to shuttle the glucose into your cells, where it's used for energy. Research is finding that keeping glucose and insulin in the right balance has important effects on metabolism and health.  

"After a healthy breakfast your blood sugar increases a little bit, but it will take a while for your body to absorb it," says Eric Rimm, Sc.D., a professor of epidemiology and nutrition at the Harvard School of Public Health in Boston. "So you might not be hungry for lunch for 5 hours."

If you don't bother with breakfast, though, the prolonged fasting might lead to a bigger than normal boost in "hunger hormones" such as ghrelin, encouraging you to overeat at your next meal and leading to spikes and dips in glucose. "Over time, if your pancreas is constantly producing insulin to compensate for high levels of glucose, it will burn out and you'll develop diabetes," Rimm says.

What you eat is important, of course. If your idea of breakfast is a doughnut and a cup of coffee, or sugary cereal and a glass of fruit juice, you're setting the stage for metabolic havoc. Fortunately, breakfast can be flavorful as well as healthy. There are plenty of traditional breakfast foods that taste great and are good for you. Our food-testing team took a close look at 33 cereals and 27 Greek yogurts—two of the most popular breakfast items—to help you pick the most nutritious and best-tasting options.

We sampled all of the products and crunched the nutrition numbers to determine which ones were winners and which ones were not so hot. No matter what your preference—something sweet and crunchy or smooth and creamy—there's a nutritious breakfast for you.

Findings from a study called the Bath Breakfast Project at the University of Bath in the United Kingdom illustrate the effect that morning meals have on glucose balance. (See infographic below.) Researchers asked a group of subjects to eat 700 or more calories by 11 a.m. and another to fast until after noon. Both groups could eat whenever and whatever they wanted the rest of the day. Blood sugar was monitored every 5 minutes.

Although the two groups ate similarly after noon, the breakfast skippers had bigger spikes and drops in glucose levels. The breakfast eaters improved their insulin sensitivity—the body's response to rises in glucose—by 10 percent. "Eating breakfast seems to have a ‘second-meal effect,' says James Betts, Ph.D., the lead researcher and a senior lecturer in nutrition and metabolism. "It primes your metabolism to maintain stable blood sugar levels after subsequent meals."

1. It may protect your heart

In a recent study that involved almost 27,000 men, researchers found that those who didn't eat a morning meal were 27 percent more likely to develop heart disease than those who did. "Our research indicates that people who skip breakfast gain weight, which can lead to diabetes as well as high cholesterol and blood pressure—all of which can raise your risk of heart disease," Rimm notes. The reason isn't entirely known, but he says that breakfast skippers tend to overeat at other meals and snack excessively throughout the day.

2. It might lower your risk of type 2 diabetes

A morning meal may help you avoid fluctuating glucose levels, which can lead to diabetes. A study of almost 30,000 men found that not eating breakfast raised the risk by 21 percent, even after taking into account their body mass, what they ate, and other factors. In a study of women, those under age 65 who skipped breakfast even just a few times per week were 28 percent more likely to develop diabetes than women who ate it regularly. And if you're in the habit of dashing out the door for work in the morning with only a cup of coffee, take note: Women in the study who worked full-time had a greater risk than those who worked part-time, the researchers noted, possibly because job stress has been found to raise glucose levels.

3. It gets you moving

In a recent study published in the American Journal of Clinical Nutrition (AJCN), people who ate breakfast were more physically active during the morning than those who didn't. That might be because a temporary increase in blood sugar gave them more energy. It's interesting to note that those who ate a morning meal consumed more calories over the course of the day than the breakfast skippers—but they didn't gain weight because they were more active.

4. It might give you a mental edge

Research involving adults and children has indicated that breakfast might enhance memory, attention, the speed of processing information, reasoning, creativity, learning, and verbal abilities. Scientists at the University of Milan in Italy reviewed 15 studies and found some evidence that those benefits might be a function of the stable glucose levels that a morning meal provides.

5. It just might keep your weight down

Although more than 100 studies have linked eating breakfast with a reduced risk of obesity, researchers point out that those studies are merely observational and thus don't prove that the meal keeps you from gaining weight. More solid evidence comes from randomized controlled trials. One study of that type, published in the journal Obesity, found that overweight people who were dieting and ate more calories for breakfast than dinner lost more weight compared with subjects who ate larger evening meals. But other trials have been inconclusive. A study published in AJCN found that eating or skipping breakfast had no effect on weight loss, although it may have been too small to be meaningful.