An American research team have uncovered the effect of aroma when people make the selection between healthy and unhealthy food.

Researchers from the marketing department at the University of South Florida in Tampa set out to understand how food-related ambient scents affected food choices.

The team found people exposed to an unhealthy food aroma for 30 seconds or less were more likely to make an unhealthy food selection.

When exposed to the aroma of an unhealthy food for two minutes or longer however, they found people were more likely to make healthy food choices.

The fascinating findings have been published in the Journal of Marketing Research, contributing insight into the psychology behind the worldwide obesity epidemic.

One of the team’s experiments used a school cafeteria frequented by 900 children across a period of three days which involved a control condition with no scent, an ambient aroma of pizza, and an ambient aroma of apples.

Using nebulisers to distribute the aroma near the children standing in line for food, researchers purposely slowed down the line so they would be exposed to the scent for at least two minutes.

On the day the apple was present, 36.96 per cent of the items sold were unhealthy, while on the control day, 36.54 per cent were unhealthy – an insignificant different between the two.

On the pizza aroma day however, only 21.43 per cent of items sold were unhealthy.

“We propose that this occurs because scents related to an indulgent food satisfy the reward circuitry in the brain, which in turn reduces the urge for actual consumption of indulgent foods,” the authors wrote.

The results were mimicked in a second study using cookie aromas and strawberry aromas on participants before asking them which of the two snacks they would choose after two minutes.

Those exposed to the ambient aroma of the unhealthy food were once again significantly more likely to choose the healthy option.

The published version of the study can be accessed here.