Researchers from the McGill University in Montreal,
Canada have revealed that a hormone called ghrelin seems to play a vital role
in making food seem more appealing when people are really hungry.
The study found through brain scans that volunteers had a
bigger effect of desire when they were shown pictures of food after an
injection of the hormone. Using functional magnetic resonance imaging (fMRI),
the researchers assessed the brain's response to food and non-food images in 12
volunteers who were given ghrelin and 8 others who did not receive the hormone.
"When you go to the supermarket hungry, every food
looks better. Your brain assigns a cost versus benefit to every food item. Now,
we've found that it is ghrelin that acts on the brain to make food more appealing,"
said lead researcher Dr Alain Dagher, from McGill University.
The brain scans showed that ghrelin was responsible for
increasing activity in the reward centers of the brain.
"Food pictures become even more salient - people
actually see them better. It influences not only visual processing, but also
memory. People remembered the food pictures better when ghrelin was high,"
said Dr Dagher.
The details of the
study appear in the journal Cell Metabolism.