White bread consumption may be making you fat, according to a recent study HealthDay News reported.

Spanish researchers found that those who ate three or four slices of white bread per day are at a 40 percent higher risk of becoming overweight or obese than eating just one portion a week. People who favor whole grain bread also have a lower risk of gaining weight.

"The issue is that white bread is made with highly refined flour which is rapidly absorbed as sugar," Miguel Martinez-Gonzalez, researcher and a professor at the University of Navarra in Spain, told The Independent. "Essentially it is equivalent to a high consumption of sugar. The problem is similar to what we see with soft drinks, their sugars are rapidly transformed into fat an organism."

For the study, researchers tracked the eating habits of more than 9,000 young adults for an average of five years to assess the impact of white bread on a population where bread is a major part of the diet, HealthDay News reported.

They found that participants who ate both white and whole grain breads did not have an increased risk for weight gain. But those who ate large amounts of white bread - two or more portions - were 40 percent more likely to become overweight or obese than those who ate less than one portion of white bread a week.

The researchers found no significant link between eating whole grain bread only and becoming overweight or obese. Martinez-Gonzalez said this may be because of the types of carbohydrates, fiber content and other ingredients in whole grain bread. , HealthDay News reported.

"A sensible recommendation would be to switch to wholegrain bread, especially for people who usually consume a lot of bread," Martinez-Gonzalez said.

The findings were recently presented at the European Congress on Obesity.