A research study relayed by The New York Times conludes at this time that just the scent in particular of extra virgin olive oil and especially the Italian varieties which are particularly aromatic and rich in Hexanal (scent of freshly cut grass), triggered a continuous satiety response in the subjects studied when it was substituted for control with real olive oil...
Canola oil did not present the same benefits despite presenting a similar dietetic profile. Butter, which could be considered to offer a richly flavored aroma - especially when cooked perhaps, or for rarer, very fresh springtime, grassy varieties which they probably did not use - did not trigger that response.
It has been known for a while common sensically that richly flavored foods are more immediately satisfying.
But apparently, not all rich aromas have the same effect on our psyches.
We wonder what they would make of Argan oil, which smells in part of fruity olive.
"The research found that compared to other oils and fats, extra virgin olive oil was more likely to increase a person’s feelings of satiety after a meal. But another phase of the study showed that just imparting the scent of olive oil to food – by adding an aromatic extract – reduced the amount of calories people in the study consumed and improved their blood sugar response."
Read more in Is the Secret to Olive Oil in its Scent?