The findings, reported in the Journal of Neuroscience, suggest that a hormone known as ghrelin could enhance the ability to find and identify food.
The new study shows ghrelin, made mainly in the stomach, binds to molecules in the brain's smell centre (olfactory bulb), suggesting the hormone is directly involved in odour processing.
“This new function of ghrelin was unknown prior to our discovery,” said the study’s lead author Dr Jenny Tong, from the University of Cincinnati.
“We think ghrelin is part of an important interface designed to help detect calories in our environment and to link those sensory inputs with the internal regulation of metabolism and body weight,” added Tong.