Researchers revealed some of the most addictive foods include highly-processed items such as pizza, French fries, and chocolate.

The study is the first to determine which specific foods are strongly linked to "food addiction," which is a major contributor to the obesity epidemic, the University of Michigan reported. Past animal studies have shown that highly-processed foods tend to be perceived as more delicious, but it was unknown if these types of foods could trigger addictive behaviors. Clinical studies have observed that some individuals meet the criteria for substance dependence for food.

"If properties of some foods are associated with addictive eating for some people, this may impact nutrition guidelines, as well as public policy initiatives such as marketing these foods to children," said Erica Schulte, a U-M psychology doctoral student and the study's lead author.

The recent study showed individuals with symptoms of food addiction of who had higher body mass indexes tended to have greater problems with processed food. They also tended to be more susceptible to the "rewarding "properties of processed foods. Unprocessed foods that do not contain added fat or refined carbohydrates (such as brown rice and salmon) were not associated with addictive eating behaviors.

"This is a first step towards identifying specific foods, and properties of foods, which can trigger this addictive response," Schulte said. "This could help change the way we approach obesity treatment. It may not be a simple matter of 'cutting back' on certain foods, but rather, adopting methods used to curtail smoking, drinking and drug use."

In the future, the researchers plan to look at whether or not addictive foods trigger changes in brain circuitry and eating behaviors.

The findings were published in a recent edition of the journal PLOS One.