People who eat breakfast are significantly less likely to be obese and diabetic than those who usually don't, researchers reported at the American Heart Association's 43rd Annual Conference on Cardiovascular Disease Epidemiology and Prevention.
In their study, researchers found that obesity and insulin resistance syndrome rates were 35 percent to 50 percent lower among people who ate breakfast everyday compared to those who frequently skipped it.
"Our results suggest that breakfast may really be the most important meal of the day," says Mark A. Pereira, Ph.D., a research associate at Children's Hospital in Boston and assistant professor at Harvard Medical School. "It appears that breakfast may play an important role in reducing the risk of type 2 diabetes and cardiovascular disease."
Pereira says eating breakfast might have beneficial effects on appetite, insulin resistance and energy metabolism. "Just the habit of filling your belly in the morning might help people control their hunger throughout the day so they might be less likely to overeat in the morning or at lunch," he says.
"Or, there might be a hormonal basis for some of the effects because the hormone insulin controls blood sugar and blood sugar level is related to how hungry or energetic a person feels."
Insulin resistance syndrome is a metabolic disorder characterized by the combination of several factors such as obesity, high abdominal body fat, high blood pressure, and high fasting levels of blood sugar or the hormone insulin, which helps the body store glucose properly.
The syndrome also often includes problems in blood fat metabolism such as high levels of triglycerides and low levels of high-density lipoprotein (HDL – the "good" cholesterol). Although people with insulin resistance syndrome may not yet have diabetes, their bodies do not use glucose efficiently and those with the condition are at greater risk of developing type 2 diabetes as well as heart disease.
The risk reduction for obesity and insulin resistance was consistent for white men and women and for black men but not for black women, a difference the researchers are continuing to study, Pereira says.
Overall, about 47 percent of the whites and 22 percent of the blacks reported daily breakfast consumption. "Dietary patterns are known to differ widely, probably due to cultural differences, by race and ethnicity and even between men and women," he says.
The subjects included 1,198 black and 1,633 white participants of the CARDIA study whose breakfast habits and risk factors for heart disease were assessed over an eight-year period (1992-2000). Participants were aged 25-37 in 1992. The study results accounted for risk factors such as smoking, low physical activity, alcohol use and demographic factors. The CARDIA study is a prospective study of heart disease risk factors among young adults in four communities: Minneapolis; Oakland, Calif.; Chicago, and Birmingham.
This large, prospective study of young adults from two different racial groups makes a unique contribution to the literature, Pereira says. But, it's limited because researchers can't determine cause and effect from a self-reporting study.
"We need to do more research," he adds. "We have started looking at what people are eating when they eat breakfast, which led to our finding that eating whole-grain cereal each day was associated with a 15 percent reduction in risk for the insulin resistance syndrome."
Whole-grain cereals were defined as those that list a whole grain or bran first in the ingredients list or those that contain a whole grain and have at least 2 grams of fiber per serving.