(HealthDay)—If you're watching your weight, you may have to watch your white bread consumption, too.
When white bread is a diet staple, you may be more likely to become overweight or obese than if you favor whole grain bread, according to a new study.
Researchers tracked the eating habits and weight of more than 9,200 Spanish university graduates for an average of five years.
Participants who ate both white and whole grain breads were not at increased risk for weight gain. But those who ate only white bread and had two or more portions of white bread a day were 40 percent more likely to become overweight or obese than those who ate less than one portion of white bread a week, according to the study authors.
There was no significant link between eating whole grain bread only and becoming overweight or obese. This may be because of the types of carbohydrates, fiber content and other ingredients in whole grain bread, according to Miguel Martinez-Gonzalez, a professor at the University of Navarra in Spain, and colleagues.
"Consumption of white bread [of] two portions per day or more showed a significant direct association with the risk of becoming overweight or obese," they concluded.
The study was scheduled for presentation Friday at the European Congress on Obesity in Bulgaria. The research doesn't actually show a cause-and-effect relationship between white bread consumption and weight gain, just an association. And study results presented at meetings should be considered preliminary until published in a peer-reviewed medical journal.
Explore further: People who get food assistance are eating more whole-grain products
The U.S. Centers for Disease Control and Prevention explains how to achieve healthy weight.