New research from the Agricultural Research Service of the U.S. Department of Agriculture shows that pistachios may contain fewer calories per serving than originally determined.

The research found that fat in pistachios may not be completely absorbed by the body, according to a news release.

“Existing scientific research indicates that fat from nuts is poorly absorbed through the gastrointestinal tract,” David Baer, a lead researcher of the study and supervisory research physiologist with the Beltsville Human Nutrition Research Center, said in the release. “This study confirms that the fat from pistachio nuts, specifically, is not completely digested or absorbed, resulting in a lower energy value.”

The study had 16 healthy adults eat pistachios as part of a controlled diet and measured the energy value of pistachios by calculating the differences in energy excretion. The resulting energy value of one 30 gram serving of pistachios was 5.9% less than previous calculations.

Researchers also found data that reinforced the heart health benefits of pistachios. The study found that when healthy individuals added 1.5 to 3 ounces of pistachios into their typical diets, they saw cardio-supportive results.

The findings of the study were presented at the Experimental Biology conference in Washington, D.C. April 11.