Olive oil is already famed for being a heart-healthy part of the Mediterranean diet. But now a new study finds that it may have a surprising benefit. Unlike low-fat food products and other natural fats, olive oil helps to regulate the sensation of feeling full after eating, which could help keep your fingers off the nibbles between meals.

Researchers from Technische Universität München (TUM) and the University of Vienna studied four different edible fats and oils: lard, butterfat, rapeseed oil and olive oil.

Over a period of three months, study participants ate 500 grams of low-fat yogurt enriched with one of the four fats or oils every day -- as a supplement to their normal diet.

"Olive oil had the biggest satiety effect," reports lead researcher Peter Schieberle of TUM. "The olive oil group showed a higher concentration of the satiety hormone serotonin in their blood. Subjectively speaking, these participants also reported that they found the olive oil yogurt very filling."

During the study period, no member of this group recorded an increase in body fat percentage or weight.

Findings in the study also revealed that olive oil's aroma plays a part in its ability to make a person feel satiated. The researchers used olive oils from Spain, Greece, Italy and Australia for their study and found that the Italian oils contained larger amounts of two aroma compounds, Hexanal and E2-Hexanal.

"Our findings show that aroma is capable of regulating satiety," adds Schieberle. "We hope that this work will pave the way for the development of more effective reduced-fat food products that are nonetheless satiating."