The smell of a rich dessert can make your mouth water. But can an extra helping of its smell help you eat less?

To find out, researchers enlisted 10 adults, lots of vanilla custard and zero spoons—because the custard was squeezed directly into each subject's mouth, in amounts the subject controlled. With each taste, subjects also got a blast of the custard aroma puffed into the back part of their nose.

And when subjects smelled a stronger custard aroma, they took smaller samples than when the scent was weaker or imperceptible. The findings are in the journal Flavour. [Rene de Wijk et al, Food Aroma Affects Bite Size]

Why the smaller portions? The stronger aroma might signal to the brain that the food is richer and higher in calories—thus more filling. But regardless of mechanism, the researchers suggest that making food more aromatic might induce people to take smaller mouthfuls. And such smaller bites have been shown to help people feel fuller faster and eat less overall.

A whiff of a madeleine prompted Proust to remember an entire life. But many people would be grateful if it just helped them lose a few pounds.

—Katherine Harmon

[The above text is a transcript of this podcast.]