A breakfast of meat and eggs or nothing at all linked to extra weight, finds new study
BERKELEY – People who skip breakfast or who chow down on meat and eggs for their morning meal are more likely to carry extra weight than those who eat other foods, according to a new study by researchers at the University of California, Berkeley.
"Skipping breakfast has already been established as a risk factor for being overweight, but our study is the first to really look at how different breakfast types may affect weight while controlling for lifestyle and demographic variables," said Coralie Brown, co-author of the paper and a graduate student at UC Berkeley's School of Public Health at the time of the study.
The study, published Aug. 1 in the Journal of the American College of Nutrition, comes at a time when the proportion of American adults who skip breakfast has increased from 14 to 25 percent between 1965 and 1991. The number of obese adults in the United States has also grown, jumping from 23 percent in 1994 to 31 percent in 2000, according to the U.S. Centers for Disease Control and Prevention.
"More and more Americans are skipping breakfast as the pace of our lives becomes increasingly hectic," said Gladys Block, UC Berkeley professor of nutritional epidemiology and principal investigator of the study. "What our study shows is that if the goal is to lose or maintain weight, skipping breakfast is not a good way to go about it. Skipping breakfast may be just as bad as eating a chunk of cheese first thing in the morning."
The researchers analyzed data from 16,452 adults who participated in the Third National Health and Nutrition Examination Survey, or NHANES III, from 1988 to 1994. The data included body mass index (BMI) measurements, age, gender, race and other demographic information. The researchers also controlled for such factors as physical activity and smoking, and placed participants in one of 10 breakfast categories based upon the foods they reported eating the prior day.
So which category topped the list with the lowest average BMIs? According to the study, funded by Kellogg Company, the cereal manufacturer, people who ate ready-to-eat cereal, cooked cereal or quick breads for breakfast had significantly lower body mass index (BMI) measurements than those who ate meat and eggs or nothing at all. While Kellogg reviewed the paper, the company had no editorial control over its contents.
Unexpectedly, people in the quick bread category - which includes pastries, cookies and waffles - were among those with lower BMIs compared to other groups.
"That was a really surprising result for us," said Brown, who received her UC Berkeley master's degree in public health nutrition in May. "One possible explanation is that many of the people in the quick bread category were actually eating a formal breakfast with pancakes and waffles rather than a pastry on the run. Having breakfast is associated with a more organized meal pattern. Prior studies have suggested that people who follow more organized meal patterns are less likely to be obese because they are less likely to impulsively overeat or grab something quick and fatty at other times of the day. However, that is just a theory. We're really not certain why we got that result."
The study also included fruit and vegetable and beverage categories, but when those categories were compared to other groups, no significant differences in BMI were found.
The researchers went on to calculate the total calories the participants consumed for the entire day. They found that meat and egg eaters, consistent with their higher average BMIs, ate significantly more calories throughout the day than those in most of the other groups. The exception is for people who ate foods in the dairy, quick bread and cooked cereal categories.
"It appears that foods with low levels of insoluble fiber, such as meat and eggs, are linked to excess weight," said Brown. "That could be because insoluble fiber takes longer to digest, so you feel full longer. That may help prevent overeating later in the day."
Breakfast skippers had the lowest level of calorie consumption among the groups, a finding that seems at odds with the high BMIs associated with this category.
One possible explanation, said the researchers, is that people who choose to skip breakfast may already be overweight and are trying to cut down on calories by skipping a meal. It may also be because overweight individuals in this group underestimated the amount of food they ate and reported smaller portion sizes than they actually consumed.
Another possibility is that the breakfast skippers are eating the bulk of their calories later in the day. The researchers point to prior studies showing that eating larger meals in the evening rather than spacing the calories throughout the day contributes the most to weight gain.
"Overall, our findings support the theory that a low-fat, high fiber breakfast is associated with less weight," said Brown. "It could also point to the significance of organized meals. Foods that are eaten 'on-the-run' are typically high in fat and can lead to weight gain."
Other authors of the study are Marion Dietrich, a UC Berkeley food chemist working in nutritional epidemiology; and from Kellogg, Sungsoo Cho, director of nutrition, and Celeste Clark, vice president of corporate and science affairs.