BIRMINGHAM, ALA. — A new study from the University of Alabama at Birmingham shows that while an association exists between breakfast and weight management, the question of whether eating vs. skipping breakfast affects weight has not been answered by research.
A team led by David Allison, Ph.D., associate dean for science in the U.A.B. School of Public Health, said studies designed to find links between two things, like breakfast habits and obesity, often do not prove that one causes the other.
Andrew Brown, Ph.D., first author of the new study recently published on-line in the American Journal of Clinical Nutrition, led the examination of 92 studies about the proposed effect of breakfast on obesity. The related research literature, the authors found, seemed to be influenced by factors that led to exaggerated beliefs and statements about the purported effects of breakfast consumption on obesity. These include research that lacks probative value and biased research reporting, according to the U.A.B. researchers.
“We specifically found that research articles tended to overstate the strength of study designs and ignored evidence that did not support the proposed effect of breakfast on obesity,” Dr. Brown said. “These distortions leave readers believing that the relationship between breakfast and obesity is more strongly established by science than the data actually support.”
Dr. Allison and his team found that scientists collectively do not know as much about the relationship between skipping breakfast and obesity as previously thought, based on the current state of the related research.
The meta-analysis indicated there is certainty that breakfast-skipping and obesity are associated, but it cannot confirm whether there is a causal effect of skipping breakfast on obesity.
“Although we know that breakfast-skippers are more likely to be overweight or obese, we do not know if making breakfast-skippers eat breakfast would decrease their weight,” Dr. Brown said. “Nor do we know if making breakfast-eaters stop eating breakfast would cause them to gain weight.”
The authors suggest that if causal claims are desired, different research on the topic is needed. They called for stronger study designs that include randomizing people to eat or skip breakfast to help determine causal effects of breakfast on obesity. The U.A.B. is leading such a trial in roughly 300 adults at five sites around the world; results from the study are expected in spring 2014.
“Uncertainty should not be confused with evidence of no benefit or harm, though,” Dr. Allison said. “It just means that right now we don’t know how changing breakfast-eating habits will influence obesity — eating versus skipping breakfast could help control weight, cause more weight gain or have no effect — and the effect may vary from person to person.”