New research from the University of Navarra in Spain suggests eating two or more servings of white bread a day increases the risk of obesity 40 percent.

The findings, presented this week at the European Congress on Obesity, held in Belgium, evaluated the relationship between white bread and weight change within several thousand study participants in Mediterranean Spain, where white bread is the staple.

The higher risk of being overweight or obese in those who consumed two or more daily helpings was compared to individuals who limited their white bread intake to one serving per week.

For an average length of five years, the researchers followed a total of 9,267 graduates of the school's SUN project, an ongoing study on the affects of diet on various health conditions.

The results revealed that generalized consumption of bread, which included types of white as well as whole wheat breads, was not associated with a jump in weight gain.

However, there was a definite risk boost when only white bread was eaten.

"The nature of the carbohydrate content of fiber and other micronutrients in wholemeal bread and slower absorption of carbohydrates may explain the lack of association between consumption of these and obesity," the study authors concluded.

Another study in the mid-2000s by Tufts University in Boston found calories from white bread and other refined grains seem to go to the gut and hang out as belly fat.

The Tufts researchers followed the eating habits of a group of healthy, largely middle-aged people in Baltimore, focusing on 459 people with a variety of eating habits, including some who liked eating refined grains and others who preferred fiber, such as whole grains, fruits and vegetables.

The Tufts study noted that, for some reason, calories from refined grains settled more often at the waistline and the belt sizes of those in the white bread-eating group expanded about one-half inch a year.

So, at the end of the three-year experiment, the white bread group clearly demonstrated three times the gut gain of those in the fiber-consuming group.

People who ate less fiber, that earlier study concluded, were more round.